/     THf      % 
O   LieSARIES  ^ 


^    KJL?  J 

\  mSS3  ^ 


^'ry  Of    »»* 

HEALTl 
3CI£» 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/americantextbook1905kirk 


LIST  OF  CONTRIBUTORS. 


ANGLE.  EDWARD   H.,  M.  D.,  D.  D.S. ; 

BURCHARD,  HENRY  H.,  M.  D.,  D.  D.  S. ; 

CASE.  CALVIN    S.,  M.  D.,  D.D.S.; 

CLAPP.  DWIGHT   M..  D.M.D.; 

CRENSHAW,  WILLIAM,  D.  D.S.; 

CRYER,  M.H.,  M.D.,  D.  D.  S. ; 

DARBY,  EDWIN   T..  M.  D.,  D.D.S.; 

GODDARD,  C.  L.,  D.D.S.; 

GUILFORD,  S.  H.,  A.M..  D.D.S..  Ph.D.; 

HEAD,  JOSEPH   B..  M.D.,  D.  D.  S. ; 

JACK,  LOUIS.  D.D.S. ; 

KIRK,  EDWARD   C.  D.  D.  S. ; 

NOYES.  FREDERICK   B..  B.  A.,  D.D.S. ; 

OTTOFY.  LOUIS.  D.D.S.; 

PEIRCE.  C.  N..  D.D.S.; 

THOMAS.  J.  D..  D.  D.  S. ; 

THOMPSON.  ALTON  HOWARD.  D.D.S. 

TRUMAN,  JAMES.  D.D.S. 


THE 


AMERICAN  TEXT-BOOK 


OF 


OPEPiATIVE  DENTISTRY. 


m  CONTRIBUTIONS  BY  EMINENT  AUTHORITIES. 


EDITED  BY 


EDWARD   C.  KIRK,  D.D.S., 

Professor  of  Clinical  Dentistry  in  the  University  of  Pennsylvania,  Philadelphia; 
Editor  of  "The  Dental  Cosmos;"  Officier  de  l'Academie  de  France. 


THIRD  EDITION,  REVISED  AND  ENLARGED. 


ILLUSTRATED  WITH   875   ENGRAVINGS. 


LEA   BROTHERS   &  CO., 

PHILADELPHIA    AND    NEW    YORK. 

1905 


Ksd 


Entered  according  to  Act  of  Congress  in  the  year  1905,  by 

LEA   BROTHERS   &  CO., 

in  the  Office  of  the  Librarian  of  Congress,  at  Washington.    All  rights  reserved. 


WESTCOTT    &    THOMSON. 
ELECTROTYPERS.    PHIU*0*. 


WITH  THE  CONSENT  OF  THE  CONTRIBUTORS 

THIS  BOOK  IS  DEDICATED  TO 

JAMES    TRUMAN,   D.D.  S., 

THE   CHARACTERISTIC  OF  WHOSE    LONG    PROFESSIONAL    CAREER    HAS 

BEEN  THE  INCULCATION  OF  THE  PRINCIPLES  UPON 

WHICH  THE  WORK  IS  BASED. 


PREFACE  TO  THE  THIRD  EDITION. 


The  early  exhaustion  of  the  second  edition  of  this  work  has  afforded 
opportunity  for  its  complete  revision,  the  results  of  which  are  now  pre- 
sented in  a  third  edition.  The  excellent  chapter  on  Dental  Embryology, 
by  Dr.  R.  R.  Andrews,  has  been  omitted  because  the  growth  of  that 
subject  and,  indeed,  of  all  that  pertains  to  dental  anatomy  and  histology 
has  compelled  the  retention  in  this  work  of  only  those  special  anatomical 
features  which  are  directly  applicable  to  the  elucidation  of  dental  oper- 
ative procedures.  The  number  of  excellent  treatises  now  exclusively 
devoted  to  dental  embryology  and  histology  makes  it  no  longer  neces- 
sary to  include  the  general  treatment  of  these  topics  in  a  work  strictly 
devoted  to  Operative  Dentistry. 

As  new  matter,  there  has  been  added  to  this  edition  a  chapter  upon 
the  Use  of  the  Matrix  in  Filling  Operations,  by  Dr.  Crenshaw,  which, 
it  is  confidently  expected,  will  prove  to  be  an  addition  valuable  and 
helpful  to  teachers  as  well  as  to  students. 

The  section  on  Orthodontia  has  been  treated  anew,  from  the  stand- 
point of  occlusion  as  the  scientific  basis  from  which  this  important 
departure  should  be  studied. 

With  the  cordial  consent  of  the  late  Dr.  Clark  L.  Goddard,  the 
treatment  of  the  subject  of  orthodontia  was  committed  to  Dr.  E.  H. 
Angle,  the  chief  exponent  of  the  modern  trend  of  thought  upon  ortho- 
dontia as  a  problem  of  occlusion. 

The  text  of  each  chapter  has  been  carefully  revised  by  its  author, 
with  the  exception  of  those  originally  written  by  the  late  Dr.  H.  H, 
Burchard,  whose  work  has  been  revised  by  the  Editor. 

It  is  due  to  each  of  the  contributors  to  state  that  the  Editor  is  respon- 
sible for  the  terminology  used  throughout  the  work.  In  assuming  this 
responsibility  the  terms  upon  which  divergence  of  opinion  was  found 
to  be  greatest  were  "canine"  and  "cuspid,"  "bicuspid"  and  "premolar," 
"  maxilla  "  and  "  upper,"  or  "  superior,  jaw,"  "  mandible  "  and  "  lower," 
or  "  inferior,  jaw,"  "  approximal "  and  "  proximal."    In  each  instance  the 


8  PREFACE  TO   THE  TIIIRH   EDITION. 

term  which  seemed  to  be  most  in  harmony  with  the  trend  of  good  scien- 
tific usage  was  adopted,  regardless  of  the  preferences  of  individual 
writers,  in  order  to  avoid  confusion  and  to  secure  that  harmony  of  treat>- 
ment  so  necessary  in  a  text-book  for  the  use  of  undergraduate  students. 

The  Editor  records  his  sense  of  deep  personal  loss  in  the  death  of 
Dr.  Clark  L.  Goddard,  whose  rare  attainments,  both  as  a  man  and  as  a 
dental  teacher,  could  ill  be  spared  from  the  ranks  of  contributors  to  the 
literature  of  dentistry. 

The  thanks  of  the  Editor  are  heartily  accorded  to  his  associate, 
Dr.  Julio  Endelman,  for  his  painstaking  work  in  the  preparation  of  the 
new  and  copious  index  for  this  edition  ;  to  many  colleagues  for  helpful 
suggestions ;  to  the  contributors  for  their  cordial  co-operation  in  the 
revision  of  the  work,  and  especially  to  the  large  body  of  dental  teachers, 
whose  practical  use  of  the  work  in  the  instruction  of  their  classes  is  the 
most  satisfactory  commendation  of  its  usefulness  as  a  text-book. 

The  present  edition  is  issued  in  the  confident  hope  that  the  work 
will,  in  even  greater  degree,  merit  the  approval  which  has  been  so  gen- 
erously accorded  to  its  predecessors. 

E.  C.  K. 

Philadelphia,  1905. 


LIST  OF  CONTRIBUTORS. 


EDWARD  H.  ANGLE,  M.  D.,  D.  D.  S., 

President  of  the  Angle  School  of  Orthodontia,  St.  Louis,  Mo. 

HENRY  H.  BURCHARD,  M.  D.,  D.  D.  S., 

Late  Special  Lecturer  on  Dental  Pathology  and  Therapeutics,  Philadelphia  Dental 
College,  Philadelphia. 

CALVIN  S.  CASE,  M.  D.,  D.  D.  S., 

Professor  of  Orthodontia,  Chicago  College  of  Dental  Surgery,  Chicago,  111. 

DWIGHT  M.  CLAPP,  D.  M.  D., 

Clinical  Lecturer  on  Operative  Dentistrj',  Dental  Department,  Harvard  University, 
Boston,  Mass. 

WILLIAM  CRENSHAW,  D.  D.  S., 

Dean  and   Professor   of    Operative    Dentistry  and    Dental    Pathology,   Atlanta 
Dental  College,  Atlanta. 

M.  H.  CRYER,  M.  D.,  D.  D.  S., 

Assistant  Professor  of  Oral  Surgery  in  the  University  of  Pennsylvania,  Philadelphia. 

EDWIN  T.  DARBY,  M.  D.,  D.  D.  S., 

Professor  of  Operative  Dentistry  and  Dental  Histology  in  the  University  of  Penn- 
sylvania, Philadelphia. 

C.  L.  GODDARD,   D.  D.  S., 

Professor  of  Orthodontia,   University  of  California,    College  of  Dentistry,  San 
Francisco,  Cal. 

S.  H.  GUILFORD,  A.  M.,  D.  D.  S.,  Ph.  D., 

Professor  of  Operative  and  Prosthetic  Dentistry  and  Dean  of  the  Philadelphia 
Dental  College,  Philadelphia. 

JOSEPH  B.  HEAD,  D.  D.  S.,  M.  D., 
Philadelphia. 


10  LfSr  OF  CONTRIBUTORS. 

Lolls  JACK.  I).  I).  S., 
Philailelphia. 

EDWARD  C.  KIRK,  D.  D.  S.,  So.  D., 

Professor  of  C'linioal  Uciuistiy  and  Dean  of  the  Department  of  Dentistry  in  tlie 
Univei-sity  of  Pennsylvania,  Philadelphia  ;  Officier  de  lAcadeiuie  de  Fi-anee. 

FKKDEKICK  B.  NOYES,  B.  A.,  I).  D.  S., 

Professor  of  Dental  Histology   in  the   Northwestern  University   Dental  School, 
Chicago,   111. 

LOUIS  OTTOFY,  D.  D.  S., 

Professor  of  Clinical  Therapeutics,  Chicago  College  of  Dental  Surgery,  Chicago ; 
Attending  Dental  Surgeon  St.  Luke's  Hospital,  Manila,  P.  I. 

C.  N.  PEIRCE,  D.  D.  S., 

Professor  of  Dental  Physiology,  Dental  Pathology,  and  Operative  Dentistry,  and 
Dean  of  the  Pennsylvania  College  of  Dental  Surgery,   Philadelphia. 

J.  D.  THOMAS,  D.  D.  S., 

Lecturer  on  Nitrous  Oxid,  Department  of  Dentistry,  University  of  Pennsylvania, 
Philadelphia. 

ALTON  HOWARD  THOMPSON,  D.  D.  S., 

Profes.sor  of  Dental  .\natomy,  Kansas  City  Dental  College,  Kansas  City,  Mo. 

JAMES  TRUMAN,  D.  D.  S., 

Professor  of  Dental  Pathology,  Therapeutics,  and  Materia  Medica  in  the  I'ni 
versity  of  Pennsylvania,  Philadelphia. 


CONTENTS. 


CHAPTER   I. 

PAGE 

MACROSCX)PIC  ANATOMY   OF  HUMAN  TEETH 17 

By  Al,ton  Howard  Thompson,  D.  D.  S. 

CHAPTER  II. 

DENTAL  HISTOLOGY  WITH  REFEKENCE  TO  OPERATIVE  DENTISTRY    53 

By  Fredrick  B.  Noy'es,  B.  A.,  D.  D.  S. 

CHAPTER  HI. 
ANTISEPSIS  IN   DENTISTRY 117 

By  James  Truman,  D.  D.  S. 

CHAPTER   IV. 

THE  EXAMINATION  OF  TEETH  PRELIMINARY  TO  OPERATION- 
METHODS,  INSTRUMENTS,  APPLIANCES— RECORDING  RESULTS, 
ETC 133 

By  Louis  Jack,  D.  D.  S. 

CHAPTER   V. 

PRELIMINARY  PREPARATION  OF  THE  TEETH— REMOVAL  OF  DE- 
POSITS AND  CLEANING  OF  THE  TEETH— WEDGING— OTHER 
METHODS  OF  SECURING  SEPARATION— EXPOSURE  OF  CERVI- 
CAL MARGINS  BY  SLOW  PRESSURE,  ETC 141 

By  Louis  Jack,  D.  D.  S. 

CHAPTER  VT. 
PRELIMINARY  PREPARATION  OF  CAVITIES— TREATMENT  OF  HY^- 
PERSENSITIVE  DENTINE  BY  SEDATIVES,  OBTLTSDENTS,  LOCAL 
AND  GENERAL  ANESTHETICS— STERILIZATION,  WITH  A  BRIEF 
CONSIDERATION  OF  THE  PHYSIOLOGICAL  AND  THERAPEUTICAL 
ACTION  OF  THE  MEDICAMENTS  USED 149 

By  Louis  Jack,  D.  D.  S. 

11 


12  CONTENTS. 

CHAPTER   VII. 

PAGF. 

PREPARATION  OF  CAVITIES— ol' KM. \(  i  TIIK  CAVITY— RKM()VIN(i 
THE  DECAY— SIIAPI.XC  THE  (  A  VITY  CLASSIFICATK  )N  OF 
CAVITIKS 175 

By  S.  11.  GuiLFOKD,  A.M.,  D.  I).  S.,  Pii.  U. 

CHAPTER    VIII. 
EXCLCSION  OF    MOISTURE— EJECTION  ()F    THE   i^ALIVA— APPEIC.V 
TION  OF  THE   DAM  IN   SIMPLE   CASES,  AND  IN   SPECIAL  CASES 
PRP:SENTING  difficult  complications— napkins  and  OTHER 
METHODS  FOR  SECURING  DRYNESS 199 

By  Louis  .I.vck,  D.  D.  S. 

CHAPTER   IX. 

THE  SELECTION  OF  FILLING  MATERIALS  WITH  REFERENCE  TO 
CHARACTER  OF  TO( )TII-STRUCTrRE,  VARIOUS  ORAL  CONDI- 
TIONS AND  LOCATIONS,  DEPTH  OF  CAVITY,  AND  PROXIMITY 
OF  THE  PULP— CAVITY  LINING  Wmi  ITS  PURPOSES 209 

By  Louis  Jack,  D.  D.  S. 

CHAPTER   X. 

TREATMENT  OF  FILLINGS  WITH  RESPECT  TO  CONTOUR,  AND  THE 
RELATION  OF  CONTOUR  TO  PRESERVATION  OF  THE  INTEG- 
RITY' OF   APPROXIMAL  SURFACES      221 

By  vS.  H.  Guilford,  D.  D.  S.,  Ph.  D. 

CHAPTER   XI. 

THE  OPERATION  OF   FILLING   CAVITIES   WITH    METALLIC    FOILS 

AND  THEIR  SEVERAL    MODIFICATIONS 227 

By  Edwin  T.  Darby,  D.  I).  S.,  M.  D. 

CHAPTER   XII. 
USE  OF  THE  MATRIX  IN   FILLING  OPERATIONS 261 

By  William  Crenshaw,  D.  D.  S. 

CHAPTER  XIII. 

PLASTIC    FILLING    MATERIALS-THEIR    PROPERTIFi^,     USES,   AND 

MANIPULATION 289 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 


CONTENTS.  13 

CHAPTER  XIV. 

PAGli 

COMBINATION  FILLINGS 329 

By  Dwight  M.  Clapp,  D.  M.  D. 

CHAPTER   XV. 

EESTOEATION  OF  TEETH  BY   CEMENTED  INLAYS 353 

By  Joseph  Head,  D.  D.  S.  M. 

CHAPTER  XVI. 

THE  CONSEKVATIVE  TREATMENT   OF  THE   DENTAL  PULP— DEVI- 
TALIZATION  AND   EXTIRPATION  OF  THE  PULP 385 

By  Louis  Jack,  D.  D.  S. 

CHAPTER  XVII. 

THE  TREATMENT  AND  FILLING  OF  ROOT  CANALS 413 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 

CHAPTER   XVIII. 

DENTO-ALVEOLAR   ABSCESS 467 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 

CHAPTER  XIX. 

PYORRHEA    ALVEOLARIS 493 

By  C.  H.  Peirce,  D.  D.  S. 

CHAPTER   XX. 

DISCOLORED  TEETH   AND  THEIR  TREATMENT 523 

By  Edward  C.  Kirk,  D.  D.  S. 

CHAPTER   XXI. 
EXTRACTION  OF  TEETH 549 

By  M.  H.  Cryer,  M.  D.,  D.  D.  S. 

CHAPTER   XXI  {Continued). 
EXTRACTION  OF  TEETH  UNDER  NITROUS  OXIDE  ANESTHESIA  .    .    621 
By  J.  D.  Thomas,  D.  D.  S. 


14  COyTKNT^. 

CHAPTER   XXI   (Concluded). 

PACK 

LOCAL  ANESTHETIC?^   AND  TooTH    EXTRACTION 631 

By  Henry  H.  Burchard,  M.  1>.,  I).  D.  S. 

chaptp:r  xxn. 

PLANTATION    OF  TEETH 639 

By  Louis  Ottokv,  I).  I).  S. 

CHAPTER   XXni. 

MANAOKMENT  OF  DECIDUOUS  TEETH 657 

By   CI.A14K   GoDDAKD,    A.  ^l.,    I).   I).  S. 

CHAPTER   XXIV. 

oKTIIoDoNTlA 677 

By  Edwakp  H.  Angle,  M.  D.,  D.  D.  S. 

C^HAPTER  XXV. 
THE  DEVELOPMENT  OF  ESTHETIC   FACIAL  CONTOURS 849 

By  Calvin  S.  Ca.se,  D.  D.  S.,  M.  D. 


INTRODUCTORY. 


A  STUDY  of  the  advances  which  have  of  recent  years  taken  place  in 
the  field  of  Operative  Dentistry  will  reveal,  besides  the  important  addi- 
tions to  our  knowledge  in  the  shape  of  novel  methods  and  improved 
technique,  a  vastly  more  important  advance  manifested  in  a  better  and 
more  general  understanding  of  scientific  principles,  and  the  application 
of  dental  science  to  dental  art,  resulting  in  a  more  rational  practice. 
Especially  is  this  true  in  regard  to  the  etiology  of  dental  and  oral 
pathological  conditions,  and  the  rationale  of  the  modes  of  treatment 
indicated  for  the  morbid  states  constantly  confronting  the  dental 
practitioner. 

The  modifications  in  surgical  methods  and  the  greatly  improved 
results  which  are  the  outgrowth  of  modern  scientific  studies  in  bacterial 
pathology,  while  they  have  made  a  considerable  impress  upon  dental 
operative  methods,  have  not,  however,  received  that  universal  practical 
acceptance  among  dental  operators  which  their  immense  importance 
demands.  There  is  no  field  of  special  surgery  in  which  the  import- 
ance of  exact  knowledge  with  respect  to  aseptic  and  antiseptic  treat- 
ment is  more  marked  than  in  the  practice  of  dentistry.  The  dental 
operator  is  continually  confronted  with  septic  conditions,  so  that  pre- 
cise knowledge  of  their  origin,  causes,  phenomena,  and  treatment  are 
essentials  to  the  legitimate  practice  of  the  profession. 

The  performance  of  any  operation,  and  especially  those  which  are 
classified  as  capital,  with  unclean  hands  or  infected  instruments  would 
in  the  present  stage  of  surgical  art  be  regarded  as  criminal  malpractice. 
It  should  be  so  considered  in  dentistry.  The  loss  of  a  patient's  life  as 
the  result  of  surgical  septic  infection  is  no  longer  permissible.  Lack 
of  antiseptic  precautions  in  certain  dental  operations  may  directly  lead 
to  and ,  as  a  matter  of  fact  has  been  the  cause  of  fatal  results.  It  has 
been  shown  conclusively  ^  that  a  large  variety  of  pathogenic  micro- 
organisms are  almost  constant  inhabitants  of  the  oral  cavity.  In  addi- 
tion to  the  numerous  forms  which  bring  about  an  acid  reaction,  there 
are  many  specific  organisms  which  produce  in  inoculated  animals 
pyemia  and  septicemia  in  their  several  clinical  classes.  But  while  the 
dental  practitioner  is  not  often  called  upon  to  face  the  issues   of  life 

1  W.  D.  Miller,  Dental  Cosmos,  November,  1891. 

15 


1 6  INTR  OD  UCTOR  Y. 

and  (It-atli  in  tlic  course  of  his  worU,  liis  rcsj)onsil)ilitios  as  related  tx) 
the  issues  with  which  he  does  deal  demand  of  him  the  same  care  and 
thoroughness  in  order  to  attain  the  character  of  result  which  the  pos- 
sibilities of  modern  dentistry  reijuire  of  him.  In  the  following  pages 
the  importance  of  asepsis  and  antisepsis  in  dental  operations  is  con- 
stantly impressed  upon  the  mind  of  the  student. 

By  the  term  awp,si,s  is  specifically  meant  the  condition  under  which 
are  excluded  those  influences  or  causes  whit'h  induce  infection  by  patho- 
genic micro-organisms ;  when  a  tissue  or  surface  has  been  rendered 
germ-free  it  is  said  to  be  in  an  (uscptic  condition.  By  antisepsis  is 
meant  the  means  by  which  the  septic  state  is  combated  or  the  aseptic 
state  is  attained. 

Under  the  aseptic  condition  repair  of  tissues  takes  place  normally 
without  interference,  w^ounds  and  injuries  heal  with  a  minimum  of  dis- 
turbance, and  the  inflanunatory  concomitant  is  of  the  sim])lc  traumatic 
type,  without  suppuration  or  tendency  to  diffusion. 

The  aseptic  state,  in  many  operations  in  the  mouth,  is  not  readily 
attainable  and  cannot  be  maintained  for  any  length  of  time  ;  but  in  all 
operations  which  involve  the  pulp  and  pulp  chamber,  as  well  as  the 
periapical  region  through  the  pulj)  canals  of  teeth,  strict  aseptic  con- 
ditions, as  regards  external  infection,  are  perfectly  attainable  through 
exclusion  of  the  oral  secretions  by  means  of  rubber  dam,  the  use  of 
suitable  disinfectants,  and  sterilized  instruments.  It  is  the  class  of 
operations  here  alluded  to  which  are  most  prolific  of  disturbance  from 
infective  inflammations  caused  by  ignorant  or  careless  manipulation. 

The  time  is  at  hand,  if  indeed  it  has  not  already  arrived,  when  puru- 
lent inflammations  following  dental  treatment  will  be  regarded  with 
the  same  condemnation  by  the  dentist  as  by  the  general  surgeon.  The 
operative  section  of  this  work  is  written  in  full  recognition  of  the  prin- 
ciples here  indicated. 


OPERATIVE  DENTISTRY. 


CHAPTEK   I. 

MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

By  Alton  Howard  Thompson,  D.  D.S. 


1.  Definition. — The  teeth  are  properly  defined  as  hard,  calcareous 
bodies  situated  in  that  portion  of  the  alimentary  canal  near  the  ante- 
rior or  oral  extremity.  In  man  they  are  confined  to  the  oral  cavity 
and  are  supported  by  the  maxillary  bones  only.  In  the  lower  verte- 
brates they  may  be  scattered  over  all  of  the  bones  and  cartilages  sur- 
rounding the  mouth. 

2.  Function. — The  main  function  of  the  teeth  is  the  mechanical  sub- 
division of  substances  used  for  food,  preparatory  to  their  digestion  ;  these 
organs  therefore  belong  to  the  alimentary  system.  The  elements  of 
their  function  are  prehension,  incising,  crushing,  mastication,  and  insali- 
vation.  For  the  performance  of  these  various  offices,  different  forms 
of  teeth  are  found  in  the  denture  of  man.  In  lower  animals  food-habit 
induces  the  evolution  of  many  various  and  extreme  forms  of  the  teeth. 

The  secondary  offices  of  the  teeth  in  man  are  as  adjuncts  in  vocal- 
ization and  articulate  speech ;  they  also  bear  an  esthetic  relation  to  the 
mouth  and  face. 

Fig.  1. 
a  b  c  d  e 


The  formatiou  of  single  teeth  from  the  single  cone  and  its  repetition  in  complex  teeth. 

3.  Mechanical  Design. — All  tooth  forms  are  evolved  by  modification 
from  a  simple  cone,  which  is  the  primitive,  typal  form.  The  teeth  of  fishes 
and  reptiles  are  but  simple  cones,  and  those  of  higher  mammals  are 
modifications  of  the  single  cone  or  combinations  of  two  or  more  cones 

2  17 


18  MACROSCOPIC  ANATOMY  OF   Till-:   III'MAN  TEETH. 

fused  together.  Tluis  in  mkiii  the  incisors  arc  formed  of  a  single  cone, 
the  base  of  whieli  is  compressed  to  form  the  wicK-  cutting  edge  (Fig. 
1,  a).  The  canine  or  cuspid  is  a  singk'  cone,  the  base  of  which  is  com- 
pressed into  a  trihedral  point,  or  jxtinted  jnramid  (6).  The  bicuspids 
are  composed  of  two  cones  fused  together,  the  forms  of  the  cones  being 
<|uite  distinct  the  entire  length  of  the  tooth,  as  in  the  upper  bicus])ids  (c). 
The  tvi)al  upper  molar  is  fornu'd  by  the  addition  of  the  third  cone  to 
the  bicuspid  form,  as  |)hiiMly  noticed  in  the  three  roots  and  the  primitive 
three  cusps  {d).  The  usual  (juadricuspid  form  is  made  by  the  addition 
of  a  cingule.  The  lower  molar  consists  of  four  cones,  which  may  be 
j)lainly  distinguished  i)y  an  analysis  of  its  elements  (e).  Each  cone  in 
the  structure  of  a  tooth  is  surmounted  by  a  cusp  or  tubercle.  Extra  cusps 
above  the  number  of  primary  cones  are  but  cingules  or  undeveloped  cusps. 

In  the  genesis  of  tooth  forms,  therefore,  the  complex  teeth,  as  the 
bicuspids  and  molars,  are  formed  by  the  repetition  and  addition  of  cones 
and  their  accompanying  cusps,  both  laterally  and  longitudinally  of  the  jaw. 

4.  The  Dental  Arch. — The  teeth  of  man  are  arranged  around  the 
margins   of  the  upper  and  lower  jaws  in  close   contact,  and  have  no 


Fig.  2. 


Square.  Rounded  Square.  Rounded.  Rounded  V. 

The  main  types  of  the  dental  arch. 

interspaces  between  them.  The  basal  arch  is  a  graceful  parabolic  curve, 
with  some  variations  which  lead  from  the  round  arch  to  the  incomplete 
parallelogram  or  even  to  a  well-defined  V  shape.  These  variations  may 
be  classified  as  follows : 

First:  The  square  arch  (Fig.  2,  a).  This  is  found  usually  in 
persons  of  strong  osseous  organization,  of  Scotch  or  Irish  descent — /.  e. 
of  Gaelic  extraction — and  is  probably  derived  in  the  first  instance  from 
a  dolichocephalic  people.  The  squareness  is  more  or  less  dependent 
upon  the  prominence  of  the  large  canines,  which  stand  out  very 
markedly  at  the  angles  of  the  square.  The  incisors  present  a  flat  front 
and  project  slightly,  with  little  or  no  curve  of  the  incisive  line. 
The  bicuspids  and  molars  fall  backward  from  the  canines  with  no  per- 
ceptible curve.  The  two  sides  are  quite  parallel,  but  sometimes  there 
mav  be  a  slight  divergence  toAvard  the  cheek  at  the  rear.  This  is  the 
low  form  of  arch  which  appears  in  the  apes  and  some  low  races. 


THE  OCCLUSION  OF  THE  TEETH. 


19 


Second :  The  rounded  square  (Fig.  2,  b).  This  is  the  medium 
arch  and  is  the  form  usually  met  with  in  ordinary,  well-developed  ro- 
bust Americans.  The  canines  seem  to  be  only  so  prominent  as  to  give 
character  to  the  arch  without  a  resemblance  to  the  arches  of  the  lower 
animals.  The  incisors  are  vertical  and  the  line  curves  slightly  from 
one  canine  to  the  other.  The  bicuspid-and-molar  line  curves  slightly 
outward  from  the  canine  and  converges  at  the  rear. 

Third :  The  rounded  arch  (Fig.  2,  c).  This  is  the  circular  or 
"horse-shoe"  arch.  It  is  nearly  semicircular,  the  ends  curving  in- 
ward at  the  rear,  the  outlines  of  the  arch  tracing  a  decided  horse-shoe 
shape.  The  canines  are  reduced  to  the  level  of  the  arch,  so  that  there 
is  no  prominence  of  these  teeth.  The  bicuspids  and  molars  follow  the 
line  of  the  curve.  This  arch  is  quite  characteristic  in  some  races,  as 
the  brachycephalic  South  Germans. 

Fourth  :  The  rounded  V  (Fig.  2,  d).  In  this  form  the  round  arch  is 
constricted  in  front  or  narrowed  so  that  the  incisors  mark  a  small  curve 
whose  apex  is  the  centre.  It  is  the  arch  of  beauty  and  is  that  most 
admired  in  women  of  the  Latin  races. 

These  are  but  the  basal  forms  of  the  dental  arch.  Ordinarily,  mod- 
ifications of  these  types  occur  in  all  degrees ;  it  is  the  variations,  the 
composites,  which  are  most  met  with  in  dental  practice. 

5.  The  Occlusion  of  the  Teeth. — The  upper  teeth  describe  the  seg- 
ment  of  a  circle  larger  than  that  of  the  lower  teeth  ;  so  that  the  edges 
of  the  anterior  teeth  above  close  over  those  below,  and  the  buccal  cusps 
of  the  grinding  teeth  above  close  outside  of  the  buccal  cusps  of  the 
lower  teeth  (Fig.  3).  By  this  arrangement  the  buccal  cusps  of  the 
lower  grinders  are  received  into  the  de- 
pressions or  sulci  between  the  buccal  and 
lingual  rows  of  the  cusps  and  tubercles 
of  the  upper  molars  and  bicuspids,  and 
the  lingual  cusps  of  the  upper  grinders 
are  received  into  the  sulci  of  the  lower 
grinders.  By  this  arrangement  the  whole 
of  the  morsal  surfaces  of  these  teeth  are 
brought  into  contact  in  the  several  move- 
ments of  mastication,  .thereby  rendering 
the  performance  of  this  function  more 
effective. 

Then,  again,  the  upper  incisors  usually 
close  over  the  lower  for  one-third  of  their 
length.     This  allows  of  the  shearing  action  by  which  the  incisive  func- 
tion is  performed  as  the  edges  of  these  teeth  are  drawn  past  each  other. 

The  line  of  the  horizon  of  occlusion  (Fig.  4,  A-B)  presents  a  decided 


Incisors. 


Fig.  3. 
Bicuspids. 


Molars. 


The  relative   position  of  the  upper 
and  lower  teeth  in  occlusion. 


20 


MACROSCOPIC  ANATOMY   OF  THE   IIVMAN  TEETH. 


curve  from  front  to  rear,  of  (greater  or  less  dogrcc  in  different  forms  of 
the  arch.  Thus  it  is  hit^dj  at  the  ineisors,  curving  downward  at  the  bicus- 
pids, reaching  its  k)west  ])()int  at  the  first  niokir ;  it  cuirves  upwanl  raj)- 
idly  at  the  second  molar,  and  is  highest,  again,  at  the  third.  In  the 
rounded  arcli  the  pUme  is  more  flattened,  and  it  exhibits  the  extreme 


Fig.  4. 


The  horizon  of  the  line  of  occlusidn  and  plane  of  occlusion. 

downward  curve  in  the  square  arch.  Between  these  extremes  there 
is  of  course  every  variety  of  modification.  The  form  of  the  plane  of 
occlusion  is  shown  in  Fig.  4,  C 

Fig.  5. 


The  apposition  of  the  upper  and  lower  teeth. 


The  tendency  of  the  bolus  of  food  is  toward  the  lowest  part  of  the 
curve  at  the  region  of  the  lower  first  molar,  so  that  the  extraction  of 
this  tooth  always  affects  the  performance  of  mastication. 

In  the  apposition  of  the  teeth  of  the  opposite  jaws  the  mechanical 


THE  OCCLUSION  OF  THE  TEETH. 


21 


arrangement  is  such  that  the  dynamics  of  mastication  is  subserved 
and  the  greatest  effectiveness  secured  (Fig.  5).  Thus  the  morsal  sur- 
face of  the  upper  central  incisor  is  opposed  to  all  of  that  of  the  cen- 
tral incisor  below  and  to  the  mesial  half  of  the  lateral ;  the  upper  lat- 
eral opposes  the  distal  half  of  the  lateral  below  and  the  mesial  face  of 
the  canine  ;  the  upper  canine,  the  distal  half  of  the  face  of  the  lower 
canine  and  the  mesial  half  of  the  first  bicuspid  ;  the  upper  first  bicuspid 
opposes  the  distal  half  of  the  lower  first  bicuspid  and  the  mesial  half 
of  the  second ;  the  upper  second  bicuspid  opposes  the  distal  half  of 
the  lower  second  bicuspid  and  part  of  the  lower  first  molar  :  the  upper 
first  molar  opposes  the  distal  part  of  the  lower  first  molar  and  the  me- 
sial half  of  the  second ;  the  upper  second  molar  opposes  the  distal  half 
of  the  lower  second  and  part  of  the  third ;  and  the  upper  third  covers 
the  remainder  of  the  lower  third  molar. 

By  this  method  of  apposition  the  teeth  are  so  arranged  that  two 
teeth  receive  the  impact  of  half  of  two  of  the  opposite  jaw,  thus 
distributing  the  force  of  occlusion  and  ensuring  the  safety  and  strength 
of  the  teeth.  This  "  break-joint "  arrangement  permits  each  tooth  to 
bear  two   opposing  ones,  and   also   helps  to   preserve   the  alignment. 


Fig.  6. 


Incisors.     Canines  or   Premolars  or 
cuspids.        Bicuspids. 


Molars. 
The  classes  of  the  teeth,  comprising  the  left  half  of  a  full  denture. 


Then  again,  if  one  tooth  be  lost,  the  opposing  teeth  still  rest  against 
two  teeth,  one  at  each  side  of  the  space.  The  normal  condition  of 
the  articulation  is  rarely  preserved,  however,  as  mutilation  usually  dis- 
turbs it ;  the  teeth  move  on  account  of  the  force  of  occlusion,  and  effec- 
tive mastication  is  more  or  less  destroyed. 


22  MACROSCOPIC  ANATOMY   OF   THE  IIl'MAX   TEETH. 

().  Number  and  Classes  of  the  Teeth. — Man  lias  thirtv-two  teeth, 
diviiU'd  into  four  classes,  viz. — (Ist)  ixcisoks,  (2(1)  canines  or  crspiDS, 
(3d)  I'KEMOLAPvy  or  bicuspids,  and  (4th)  molars  (Fig.  G).  This  is 
expressed  by  the  dental  formula  as  follows  : 


2—2         1  —  1    ,.    2  -  2         .3—3 

-,   e. ,  Oi.  ,  in. 

2-2'        1  —  1'        2—2'        3—3 


(1)  The  incisors  are  oigiit  in  number,  iour  above  and  four  below, — 
two  on  each  side  of  the  median  line.  The  two  next  to  the  median  line 
are  called  the  central  incisors,  the  ones  next  to  them  distally,  the  lat- 
eral incisors. 

(2)  The  canines  are  four  in  number,  two  above  and  two  below, — 
one  on  each  side  immediately  approximating  the  lateral  incisor  on  the 
distal  side. 

(3)  The  bicuspids  are  eight  in  number,  four  above  and  four  below, 
— two  on  each  side  ap])roximating  the  canines  on  the  distal  side. 
The  first  of  these  next  the  canine  is  called  the  Jird  bicuspid,  the  one 
next  to  it  on  the  distal  side  the  second  bicuspid.  The  same  designa- 
tion applies  to  both  upper  and  lower  bicuspids. 

(4)  The  molars  are  twelve  in  number,  three  on  each  side  of  each 
jaw,  approximating  the  second  bicuspid  on  the  distal  side.  The 
molar  next  to  the  second  bicuspid,  both  above  and  below,  is  called  the 
first  molar;  the  next  one  distally  is  called  the  second  molar ;  the  next 
one  distally,  and  the  last  tooth  in  the  jaw,  is  called  the  third  molar  or 
"  wisdom  tooth  "  {dens  sapientice). 

Functionally,  the  incisors  are  formed  for  cutting,  as  their  name  im- 
plies ;  the  canines  for  prehension  and  tearing  (for  which  purpose  this 
tooth  in  lower  animal  forms  is  often  excessively  developed).  It  also 
serves  in  guiding  the  bite.  The  bicuspids  are  the  crushing  teeth,  and 
the  molars  are  formed  for  grinding,  triturating  and  insalivating  the 
food. 

The  Incisors. 

7.  The  Upper  Central  Incisor. — This  is  the  first  tooth  in  the  den- 
tal series  in  man.  It  is  situated  in  the  front  of  the  mouth,  next  to  the 
centre  of  the  arch,  which  is  the  mesial  border  of  the  intermaxillary 
bone.  In  adult  man  these  bones  fuse  with  the  anterior  borders  of  the 
right  and  left  superior  maxillary  bones.  Their  junction  with  each  other 
marks  the  centre  of  the  dental  arch. 

The  general  form  is  that  of  a  truncateil  cone  with  its  base  flattened 
out  to  form  the  cutting  edge. 

Its  function  is  to  cut  or  incise  food,  hence  its  name  from  the  Lat. 
incisus,  "to  cut  into." 


THE  INCISORS. 


23 


The  mechanical  structure  of  the  croion  is  a  matter  of  importance.  It 
will  be  observed  that  it  consists  of  several  elements  :  first,  a  broad  cut- 
ting blade  (Fig.  7,  a)  supported  by  two  strong  lateral  columns  (6)  on 

each   side,  and   that  these   columns 
are  upheld  by  two  strong  marginal 

Fig.  8. 


Fig. 


The  mechanical  design  of  the  crown  of 
the  upper  central  incisor :  a,  the  blade  ;  b, 
the  two  columns  supporting  the  blade  ;  c, 
the  marginal  ridges  acting  as  guys,  brac- 
ing the  columns ;  d,  the  basal  ridge  as  the 
base  of  attachment  for  the  guys. 


d  f 

Diagram  of  the  labial  face  of  the  upper  central 
incisor. 


ridges  (c)  leading  up  from  the  lower  ridge  (d).  These  ridges  are  but- 
tresses, which  guy  and  uphold  the  columns  which  contain  and  carry  the 
blade.  Hence,  when  these  ridges  are  destroyed  by  caries  or  in  operating, 
the  support  of  the  column  is  lost  and  the  blade  readily  breaks  away. 

The  form  of  the  crown  is  spade-like,  or  a  compressed-w^dge  shape, 
the  edge  being  quite  thin  and  the  thickness  increasing  rapidly  to  the 
base.  It  is  slightly  bent  toward  the  lingual  side,  or  much  curled  over  in 
some  cases. 

The  labial  face  is  imperfectly  square  or  oblong,  the  cervical  margin 
being  rounded  (Fig.  8,  a).  It  is  convex  from  side  to  side,  but  only 
slightly  so  from  cervix  to  edge.  Two  shallow  depressions  or  furrows 
extend  the  length  of  the  face  perpendicularly  (6)  dividing  it  into 
thirds,  called  lobes, — the  mesial,  (c),  median  (d) 
and  distal  lobes  (e).  These  furrows  and  lobes  are 
quite  conspicuous  when  the  tooth  is  erupted,  but 
are  abraded  by  age  and  the  wear  of  use  and  denti- 
frices, until  the  face  becomes  smooth.  The  mesial 
margin  is  a  little  longer  than  the  distal  so  that 
the  cutting  edge  slopes  upward  toward  the  distal 
side(/).  _ 

The  lingual  face  is  smaller  than  the  labial, 
being  on  the  inner  and  smaller  curve  of  the 
crown,  and  is  narrower  from  side  to  side  (Fig.  9). 
It  is  triangular  in  outline,  being  wide  at  the  edge  and  narrow  and 
rounded  at  the  base  or  cervix.  The  marginal  ridges  (a)  are  high 
and  conspicuous,  and  extend  from  the  basal  ridge  to  the  edge  on  the 


Diagram  of  the  lingual  face 
of  the  upper  central  in- 
cisor. 


24  MACROSCOPIC  ANATOMY  OF   Till:   III' MAS    TKKTU. 

mesial  :iml  distal  inar<rins  <»f'  this  surface  Tlic  i)asal  ri(l*r«'  {!')  is  a 
stronix  elevation  eontimums  with  the  iiiar<rinal  ridges  at  the  base  of 
the  erown.  It  is  sometimes  (leNX'loped  into  a  raised  cusp,  the  ridge 
at  the  base  of  which  forms  a  cingulum.  A  ridge  or  lobe  (r)  extends 
from  the  basal  ridge  to  tlie  centre  of  the  edge,  uniting  with  the  median 
lobe  from  the  labial  face  to  form  the  median  tubercle.  A  depression 
or  fossa  {(l)  is  found  on  each  side  of  the  median  lobe  between  it  and  the 
marginal  ridges,  or,  when  the  lobe  is  low  or  entirely  absent,  these  fossae 
mav  be  continuous.  A  fault  or  fissure  at  its  junction  with  tlie  basal 
ridge  forms  the  seat  of  caries  in  teeth  of  low  structure. 

The  mesial  face  (Fig.  10)  is  a  rather  long  triangle  in  shape,  with  a 
concaved  base  at  the  cervix  of  the  tooth  (<;), 
and  a  long  point  toward  the  edge.  It  is 
nearly  straight  in  a  longitudinal  direction, 
but  rounded  and  convex  transversely.  It  is 
longer  than  the  distal  face,  the  edge  descend- 
ing in  that  direction.  The  enamel  line  dips 
doM'nward  into  this  face,  and  there  is  a  de- 
Mesial.       Distal.         9  prcssiou  above  it  (It)  which  sometimes  extends 

The  mesial  and  distal  faces  and     upward  Oil  the  root.     The  point  of  contact 

edge  of  the  upper  central   in-  •  i      i  •  i      ■ 

cisor.  With  the  opposing  tooth  is  near  the  cutting 

edge. 

The  distal  face  is  also  triangular  in  outline  (Fig.  10)  but  it  is  more 
curved  in  the  longitudinal  axis,  so  that  this  surface  is  convex  in  all 
directions.  It  is  most  curved  in  the  transverse  direction.  The  enamel 
dips  downward  into  the  surface  (r/),  as  in  the  mesial,  but  there  is  not  so 
much  of  a  depression  above  this  line.  The  point  of  contact  is  one-third 
of  the  distance  from  the  angle  (e). 

The  edge,  or  morsal  margin,  of  the  crown  is  formed  by  the  com- 
pression of  the  top  of  the  truncated  primitive  cone.  It  is  quite  wide 
and  square  except  at  the  distal  corner,  which  is  rounded.  The  angle 
with  the  mesial  face  is  acute  (Fig.  10,  /).  When  the  tooth  is  first 
erupted,  the  edge  has  three  prominent  tubercles  [g),  which  correspond 
to  the  ridges  on  the  labial  and  lingual  faces.  These  are  soon  worn  off 
with  use,  so  that  the  edge  usually  looks  straight.  The  pitch  of  the 
edge  is  toward  the  median  line. 

The  iiccl:  of  the  central  incisor  is  a  rounded  pear-shape  in  outline, 
the  labial  half  being  wider  (Fig.  11,  a)  than  the  lingual.  There  is  not 
much  constriction  of  the  tooth  at  the  neck.  The  enamel  edge  curves 
upward  on  the  root  on  the  labial  and  lingual  sides,  and  dips  down- 
ward on  the  mesial  and  distal  faces.  It  terminates  abruptly  on  all 
sides,  especially  on  the  lingual,  where  a  considerable  ridge  is  some- 
times raised  (Fig.  10,  c). 


THE  INCISORS. 


25 


Fig.  11. 


The  root  of  the  upper  cen- 
tral incisor. 


The  root  is  cone-shaped  and  tapering  (Fig.  11,  b).     The  rounded 
pear-shaped  section  continues  almost  to  the  end. 

The  pulp  chamber  is  spacious  and  open,  and  of 
the  general  form  of  the  tooth  {a  and  c).  The  radi- 
cal portion  of  the  canal  gives  free  access,  but  the 
flattened  coronal  portion  is  difficult  to  cleanse.  In 
young  teeth  the  cornua  or  horns  of  the  pulp  may 
project  far  toward  the  angles  (c). 

8.  The  Lateral  Incisor. — This  tooth  approxi- 
mates the  central  incisor  on  its  distal  side,  and  is 
also  implanted  in  the  intermaxillary  bone.  It  is 
of  similar  spade-like  form  and  of  the  same  architectural  design  as  the 
central,  modified  by  the  distal  half  being  more  rounded  in  every  direc- 
tion. As  the  crown  is  narrower  than  the  central,  the  destruction  of  the 
marginal  ridges  on  the  lingual  face  weakens  the  edge  still  more,  so 
that  it  breaks  oif  more  easily.  The  crown  is  narrower  in  the  mesio- 
distal  diameter  than  the  central,  but,  still  almost  as  wide  labio-lingually, 
the  relative  difference  of  thickness  in  the  two  directions  is  more  ap- 
parent. The  tooth  has  the  appearance  of  being  compressed  mesio- 
distally.  >The  thickness  increases  rapidly  from  the  edge  to  the  neck 
(Fig.  12,  B). 

Fig.  12. 


^^■^  B  C  D 

The  upper  lateral  incisor. 

The  labial  face  (Fig.  12,  C)  is  more  rounded  than  that  of  the  cen- 
tral. It  is  half  incisor  and  half  canine  (a),  the  mesial  half  toward  the 
central  incisor  resembling  that  tooth  (6),  and  the  distal  half  toward 
the  canine  resembling  it  (c).  The  mesial  angle  of  the  edge  is  quite 
acute,  while  the  distal  angle  is  rounded  and  obtuse.  The  three  lobes 
may  be  well  developed,  similar  to  those  on  the  central  incisor,  but 
are  usually  indistinct,  although  the  central  ridge  is  prominent. 

The  lingual  face  (Fig.  12,  D)  is  much  depressed,  but  less  concave 
than  that  of  the  central  incisor.  The  marginal  (cZ)  and  basal  ridges  (e) 
are  quite  prominent.  The  basal  ridge  is  often  raised  into  a  prominent 
cingule  or  talon,  an  exaggerated  example  of  Avhich  is  shown  in  Fig.  13, 
which  is  a  revival  of  the  basal  talon  found  in  the  lower  quadrumana, — 
and  the  insectivora.     This  cingule  oeenrs  more  frequently  on  the  lateral 


26  MACROSCOPrr  AXATOMV   OF  Till:   //r.l/.l.V    TKKTH. 

incisor  than  <m  any  otlu-r  of  tlic  anterior  t«'('tli.  The  depression 
al)ove  it  is  ofton  tlie  location  of  a  fault,  a  fissun;  or  |)it,  which  hc- 
conies  the  seat  of  caries.  The  basal  ridge  is 
sometimes  cut  hv  a  tissun-  which  leads  down  quite 
n]>on  the  neck  of  the  tooth  (Fig.  1-,/). 

Sometimes  the  entire  surface  is  full  and  rounded 
without  any  concavity  whatever. 

The  mesial  face  (g)  is  of  triangular  form  similar 

a      to  that  of  the  central  incisor.    It  is  rounded  toward 

the  edge  lahio-lingually,  but  flattened  at  the  neck, 

**  with  a  depression  at  the  enamel  line  which  leads 

Showing   unusual    develop-  *^  mi       i    i  •    i  i      • 

ment  of  the   cinguie  or   Upward  upon  the  root.      1  he  labial  angle  is  some- 

basal  talon  on  an  incisor,    ^jj^^^.^  ^j^^.  ^^,^^  ^^^- ^  depression  (/(),  wllich  givCS  the 
(From  case  reported  by  Dr.  ^  .  .         , 

w.  H.  Mitchell,  Dattai  Cos-  angle   a  hook  shape.     The  depression  varies  in 
«,o.,voi.xxxiv.p.i036.)       ^^.j^^jj^   ,^j^^j  ^l^^^^^j^    .^j^^l   j^^,j^.  become  the   seat  of 

caries.  The  point  of  contact  with  the  central  incisor  is  at  the  junction 
of  the  lower  with  the  middle  third  of  the  length  of  the  face. 

The  dktal  face  is  more  convex  in  all  directions  and  resembles  the 
canine  in  form,  being  in  harmony  with  the  general  form  of  the  distal 
half  of  that  tooth.  From  cervix  to  edge  it  is  rounded  and  the  contact 
eminence  in  the  middle  third  is  very  full  (/).  From  this  point  it  rounds 
off  rapidly  to  the  edge.  The  upper  third  is  depressed  rapidly  toward 
the  cervix,  with  a  considerable  depression  at  the  enamel  line  leading 
off  to  the  distal  groove  on  the  root. 

The  edge  is  divided  into  two  portions  by  the  prominent  tubercle  (_/) 
in  the  middle  which  terminates  the  prominent  central  ridge  of  the 
labial  face.  The  mesial  half  is  straight,  like  that  of  the  central. 
When  worn,  these  features  disappear  and  the  edge  becomes  almost 
straight.  The  pitch  of  the  edge,  like  that  of  the  central,  is  toward 
the  median  line. 

The  neck  is  much  flattened  mesio-distally,  and  is  of  a  compressed 
pear  shape,  or  flattened  oval  on  section.  The  enamel  margin  pursues 
the  same  course  as  on  the  central  incisor,  rounding  upward  toward  the 
root  on  the  labial  and  lingual  sides  and  dipping  downward  on  the 
distal  and  mesial.  It  does  not  terminate  so  abruptly  as  that  of  the 
central  incisor,  and  presents  less  of  a  ridge  at  the  gingival  margin. 

The  root  is  commonly  longer  than  that  of  the  central  incisor,  is 
narrower,  flattened  mesio-distally  (Fig,  12,  A,  B).  It  tapers  gradually, 
not  rapidly  like  the  root  of  the  central  incisor.  It  is  a  flattened  oval 
on  section  (e).  Sometimes  there  is  a  hook  at  the  end,  curved  distally. 
Grooves  sometimes  occur  on  the  mesial  and  distal  sides. 

The  pulp  canal  is  flattened  in  conformity  to  the  shape  of  the  root, 
but  is  readily  entered  if  the  root  be  straight. 


THE  INCISORS. 


27 


The  lateral  incisor  is  very  irregular  as  to  form,  presenting  various 
degrees  of  deformity  or  abnormality,  and  may  sometimes  be  reduced  to 
a  mere  peg.  It  is  also  erratic  as  to  eruption,  being  sometimes  sup- 
pressed, not  appearing  for  several  generations  of  a  family.  It  follows 
the  third  molar  in  the  frequency  of  its  irregularities  both  as  to  form 
and  frequency  of  non-eruption. 

The  third  incisor  of  the  primitive  typal  mammal  sometimes  reap- 
pears in  man,  and  is  known  as  a  supernumerary.  It  rarely  assumes  the 
proper  incisor  form  and  position  in  the  arch,  but  usually  erupts  within 
the  arch  and  is  a  mere  pointed-peg-shaped  tooth. 

9.  The  Lo^wer  Incisors. — These  are  most  conveniently  described  as 
a  group,  as  they  are  very  similar  in  form,  having  but  slight  variations 
between  the  central  and  lateral  incisors  to  be  noted. 

They  are  located  in  the  anterior  portion  of  the  lower  jaw,  upon  each 
side  of  the  median  line,  opposite  the  incisors  above.  Their  function  is  the 
same  as  that  of  the  upper  incisors,  the  cutting  of  food,  which  they  per- 
form by  opposing  the  upper.  The  lower  central  opposes  only  the  cen- 
tral above ;  the  lateral,  both  the  upper  central  and  lateral  incisors. 

The  lo-wer  central  incisor  is  the  smallest  tooth  in  the  dental  series. 
It  is  of  spade-like  form  (Fig.  14),  the  crown  being  a  double  wedge 
shape  (a,  6).  The  first  wedge  (a)  is  observed  on  viewing  the  crown 
from  the  front,  the  widest  portion  being 
at  the  morsal  edge  and  the  point  at  the 
cervix.  The  second  wedge  is  observed 
from  the  side  (6),  the  widest  part  being 
at  the  neck  and  the  point  at  the  morsal 
edge  of  the  crown.  The  edge  is  thin, 
but  the  labio-lingual  diameter  increases 
rapidly  to  the  cervix,  which  is  the 
widest  part.  The  crown  is  widest 
mesio-distally  at  the  edge,  but  diminishes  to  the  neck,  which  is  scarcely 
more  than  half  the  width  of  the  edge.  The  tooth  cone  is  therefore 
compressed  in  one  direction  at  the  edge,  and  in  another  at  the  cervix. 
The  mechanical  elements  are  the  same  as  those  of  the  upper  central,  but 
with  the  parts  less  strongly  marked. 

The  labial  face  is  a  long  wedge  shape  («),  the  widest  part  at  the 
edge  and  narrowing  to  the  cervix.  It  is  usually  straight,  or  nearly 
so,  longitudinally,  and  straight  across  the  edge,  but  round  and  con- 
vex at  the  neck  and  the  cervical  half.  Sometimes  vertical  ridges  are 
found  on  these  teeth  when  they  are  first  erupted,  but  these  soon 
wear  oif. 

The  lingual  face  is  depressed  and  concave  from  edge  to  cervix  (c), 
but  less  so  from  side   to   side.       The  marginal   ridges  are  often  well 


The  lower  incisor. 


28  MACL'OSCOI'IC  A.XA'J'O.VY    OF    TUI'.    IITMAX    TKKTII. 

marked.  In  the  lateral  ineisoi-  the  fossa  is  often  more  markeci  and 
the   mariiiiial    ridges   more  distinct. 

The  iiusidl nnd  didal  sides  are  of  wi-tlge-liki"  i'orm,  straight  from  edge 
to  cervix  and  widening  in  the  same  direction.  A  depression  runs  across 
the  neck  just  above  the  enamel  line. 

'i'he  neck  is  much  compressed  disto-mesially,  and  the  rf)ot  partakes 
of  this  flattening  through  its  entire  length.  The  section  presents  a 
compressed  oval  {e).  The  enamel  line  dips  downward  on  the  labial  and 
lingual  sides,  and  curves  upward  on  the  mesial  and  distal,  in  a  manner 
characteristic  of"  the  incisors. 

The  edge  is  perfectly  straight  from  side  to  side,  after  the  three  tuber- 
cles, found  when  first  eru])ted,  are  worn  off. 

The  root  is  flattened  like  the  neck,  and  frequently  a  groove  runs  the 
entire  length  on  the  mesial  and  distal  sides.  Occasionally  complete 
bifurcation  residts,  which  recalls  the  form  of  this  tooth  found  in  lower 
animals. 

The  pulp  canal  (e)  is  of  similar  form  t(»  the  root,  and  is  flattened 
and  thin,  so  that  it  is  often  difficult  to  effect  an  entrance  to  it  with 
instnnuents. 

The  lateral  is  similar  in  form  to  the  central  incisor,  but  is  wider  at 
the  edge  and  the  distal  corner  of  the  edge  is  slightly  rounded  (d).  In  all 
other  features  it  resembles  the  central  incisor. 

The  Canines  or  Cuspids. 

10.  The  Upper  Canine. — This  is  the  third  tooth  from  the  median 
line  and  a|>i)roximates  the  lateral  incisor  on  its  distal  side.  It  is  the 
first  tooth  |)osterior  to  the  intermaxillary  suture  and  is  imbedded  in 
the  maxilla  })roper.  It  is  commonly  said  to  form  the  spring  of  the 
arch,  and  conveys  the  impression  of  great  strength,  as  is  indicated  by 
its  strong  imphuitation.  It  is  more  strongly  implanted,  and  by  a  longer 
and  larger  root,  than  any  of  the  other  teeth.  Zoologically  it  is  the 
largest  tooth  in  the  dental  series,  but  in  man  is  much  reduced  from 
its  prototype,  the  larger  carnassial  canine  of  lower  animals,  especially 
the  carnivora.  It  is  the  principal  prehensile  tooth,  and  is  therefore 
first  in  order  of  function  in   the  dental  series. 

The  canine  in  man  preserves  the  typal  form,  for  its  mechanical 
structure  is  still  that  of  a  single  cone,  brought  to  a  point  (Fig. 
15,  a).  This  is  the  earliest  form  of  teeth  found  in  the  lower  verte- 
brates, the  fishes  and  reptiles,  which  present  only  simple  conical  teeth 
in  all  parts  of  the  jaw.  It  has  an  older  history  than  any  other  tooth, 
and  stiil  bears  the  marks  of  the  many  changes  through  which  it  has 
passed   in  the  course  of  its  evolution. 


THE  CANINES  OR   CUSPIDS. 


29 


The  crown  has  a  spear-head  shape  (6),  hence  the  name,  cuspid,  by 
which  this  tooth  is  frequently  designated,  from  the  Lat.  cuspis,  "  point, 
pointed  end."  It  is  constructed  essentially  for  piercing  and  tearing. 
The  central  cusp  or  point  is  braced  in  all  directions ;  the  edges  leading 
up  to  it  both  mesially  and  distally  (which  serve  for  cutting  as  well),  the 

Fig.  15. 


The  upper  canine. 


strong  labial  ridge  coming  downward  from  the  cervix  (c)  to  the  median 
ridge  leading  up  on  the  lingual  surface  (rf),  all  support  it  in  the  office 
of  prehension  and  the  laceration  of  flesh. 

The  labial  face  (b)  presents  the  outlines  of  the  spear  shape,  more  or 
less  rounded  in  diiferent  cases.  Starting  from  the  well-defined  cusp  just 
in  front  of  the  central  axis  of  the  tooth,  it  widens  sharply  for  about 
one-third  of  its  length,  whence  it  narrows  gradually  to  the  gum  line, 
which  is  fully  rounded.  In  some  cases  the  mesial  and  distal  angles  are 
rounded  and  the  outlines  are  more  of  a  leaf  shape  (e).  The  surface 
is  slightly  rounded  mesio-distally,  so  that  the  sides  slope  roundly  or 
flatly  away  from  the  central  ridge.  This  ridge  descends  from  the  middle 
of  the  cervical  margin,  curving  slightly  forward  and  then  backward  to 
the  point  of  the  cusp  (c).  This  curve  recalls  the  curving  shape  of  this 
tooth  in  the  Felidse.  It  is  usually  a  sharp,  prominent  ridge,  but  may 
be  reduced  and  rounded  so  as  to  be  scarcely  perceptible.  The  three  lobes 
of  the  surface  are  imperfectly  marked, — the  central  ridge  dominating 
and  dwarfing  the  lateral  ones.  The  lateral  furrows  on  each  side  of 
the  central  ridge  separating  it  from  the  lateral  lobes  are  more  or  less 
marked,  especially  toward  the  edge.  Wear  reduces  in  time  the  prom- 
inence of  the  lobes  and  ridges  and  obliterates  the  furrows. 

The  Ungual  face  is  of  similar  spear  shape  (d),  but  is  more  flat.  It  is 
rarely  concave.  The  thickness  of  the  crown  increases  gradually  to 
the  lateral  prominences,  which  gives  a  blade-like  edge,  then  rapidly 
to  the  shoulder  at  the  base.  A  strong  vertical  ridge  extends  from  the 
cusp  to  the  basal  ridge  (d),  with  a  slight  concave  depression  on  each 
side.  The  basal  ridge  is  well  marked  and  sometimes  develops  into 
a  cingule,  more  or  less  marked.     The  marginal  ridges  lead  up  on  each 


30  MACROSCOPIC  AS  ATOMY    OF    TIIK   HI-MAX    TKKTH. 

side  only  so  far  a>  the  lateral  jn-otiilHTaiico.  Tlicy  arc  not  strongly 
marked  as  a  rule.  The  fosste  on  each  side  of  the  vertical  median  ridge, 
between  it  and  the  marginal  ridges,  may  he  <|uite  deep  hut  are  usually 
shallow  and  ill  defined. 

The  mesial  face  in  outline  is  not  unlike  the  central  ineisor,  but  its 
contour  is  very  diU'erent,  for  it  is  more  or  less  rounded  in  all  direc- 
tions, and  the  lateral  eminence  in  the  lesser  third  makes  this  part  espe- 
cially full  (i).  From  this  j)oint  the  surface  is  depressed  roundly  to  the 
enamel  line  at  the  neck,  where  a  depression  of  greater  or  less  depth  is 
lound.  It  is  someNvhat  flattened  at  the  cervix.  The  point  of  contact 
is  at  the  eminence,  which  touches  the  lateral  incisor. 

The  (Jisfdl  face  is  of  similar  form  to  the  mesial,  exce])t  that  it  is  more 
full  and  the  eminence  more  pronounced,  which  gives  the  increased  width 
of  the  crown  on  that  side.  The  surface  descends  rapidly  toward  the  neck 
and  is  rounded  labio-lingually.  The  point  of  contact  with  the  first  bi- 
cuspid is  on  the  lateral  protuberance. 

The  morsal  edge  presents  a  prominent  cusp  which  is  almost  central 
to  the  long  axis  of  the  tooth.  The  side  facets  slope  away,  but  still  retain 
their  cutting  edge  (6).  The  distal  side  of  the  edge  is  longer  than  the 
mesial,  by  reason  of  the  increased  size  of  the  distal  protuberant  angle. 
The  sharp  point  is  soon  worn  off  to  a  rounded  cusp,  and,  as  wear 
increases  with  age,  it  may  be  reduced  to  a  straight  surface  between  the 
mesial  and  distal  protuberances  {</). 

The  neck  is  a  flattened  oval  on  section,  or  the  lateral  direction  of  the 
labial  portion  may  be  greater  than  that  of  the  lingual  (h).  The  enamel 
line  preserves  the  same  curves  as  on  the  incisors,  /.  e.  rounding  upward 
on  the  labial  and  lingual  surfaces  and  dipping  downward  on  the  mesial 
and  distal.  The  enamel  terminates  gradually  with  but  a  slight  ridge, 
unless  it  should  be  on  the  lingual  side.  A  depression  occurs  on  both 
mesial  and  distal  sides  above  the  curve,  which  may  lead  up  as  a  groove 
on  the  root. 

The  root  is  longer  than  that  of  any  other  tooth,  and  it  is  at  least 
one-third  larger  than  that  of  the  central  incisor.  It  is  of  a  rounded 
trihedral  form,  or  irregularly  conical.  It  is  usually  straight,  and  tapers 
to  a  slender  point,  which  may  be  curved  or  very  crooked.  In  well- 
arranged  dentures,  where  it  has  erupted  naturally,  it  is  usually  straight. 

The  root  canal  is  large  and  open,  of  the  same  form  as  the  tooth,  and 
easily  entered.  It  is  regularly  formed  excejit  in  those  cases  where  the 
root  is  curved,  and  even  in  these  it  can  be  filled  if  not  too  crooked,  as 
it  is  so  open  and  accessible. 

11.  The  Lower  Canine. — This  is  similar  to  the  u])per  in  form  and 
outline,  except  that  it  is  somewhat  smaller,  more  slender,  and  more 
rounded  in  form  (Fig.  16,  (i).     It  differs  also  in  being  more  compressed 


THE  CANINES  OB  CUSPIDS.  31 

mesio-distally  and  in  being  flattened  in  the  neck  and  root.  The  crown 
leans  backward  on  the  root  so  that  the  mesial  face  is  almost  straight  the 
entire  length  of  root  and  crown.  It  forms  the  spring  of  the  lower  arch, 
and  is  strongly  built  to  oppose  the  strong  upper  canine  in  the  act  of 
prehension  and  tearing.  It  opposes  the  mesial  surface  of  the  canine 
above  and  the  distal  surface  of  the  upper  lateral  incisor. 


b  c 

The  lower  canine. 

The  labial  face  is  a  long  oval  (a),  the  cusp  being  blunt  and  the  neck 
rounded  while  the  mesial  side  (c)  is  flattened.  The  lobes  are  indistinct 
and  the  central  ridge  rounded  from  side  to  side.  The  entire  face  is  in- 
clined inward  to  accommodate  the  occlusion.  The  crown  in  many  cases 
presents  the  appearance  of  being  blunt  toward  the  distal  side. 

The  lingual  face  (6)  is  flat,  sometimes  cup-shaped,  and  the  marginal 
ridges  are  not  prominent.  The  central  ridge  sometimes  stands  out 
strongly.  The  basal  ridge  is  weak  and  is  rarely  developed  into  a 
cingule.  The  crown  increases  gradually  in  thickness  from  the  point 
to  the  neck. 

The  morsal  surface  presents  a  mere  rounded  eminence  ;  the  cusp  may 
be  sharp  in  childhood,  but  usually  it  is  soon  reduced  by  wear.  Some- 
times it  remains  sharp  and  prominent.  The  lateral  edges  are  not  devel- 
oped, but  are  mere  ridges  leading  down  to  the  lateral  faces,  which  are 
not  prominent,  except  the  distal  (d),  which  is  often  full. 

The  mesial  face  is  quite  flat,  and  straight  with  that  face  of  the  root. 
The  eminence  is  not  marked.  It  is  rounded  only  at  the  eminence,  but 
flattened  at  the  cervical  third  (c). 

The  distal  face  has  the  most  prominent  eminence  (d),  the  crown  being 
bent  in  that  direction.  The  cervical  third  of  this  face  is  flat.  It  descends 
rapidly  from  the  eminence. 

The  neck  is  usually  oval  (/)  or,  when  compressed,  spindle-shaped 
upon  section  (g),  being  depressed  on  the  mesial  and  distal  sides  at  the 
origin  of  the  grooves  running  up  on  the  root.  The  enamel  line  is 
not  so  variable  as  on  the  incisor,  but  more  nearly  on  a  level  on  all  four 
aspects. 


32 


MACROSVOl'lV  ASATOMY    >>/■•   TJI/-:   ^[l'^fA^   TEETH. 


The  mot  is  lontx,  Hattciicd,  and  tajx-rin^  {<t,  h,  c).  It  is  shorter  tlian 
that  of  the  upper  canine.  It  is  grooved  on  the  mesial  and  distal  sides, — 
so  much  so  as  to  tend  toward  bifurcation.  This,  indeed,  sometimes  hap- 
pens in  man,  thereby  ri'calling  the  Ibriu  usual  to  the  ])riniates  and  some 
other  lower  animals. 

The  root  canal  is  of  tlie  same  general  form  as  the  root,  often  pre- 
senting the  spindle  shape  on  section.  It  is  somewhat  difficult  to  enter 
on  account  of  its  flattened  shape  and  narrowed  channel. 


Fig.  17. 


b  c 

The  upper  bicuspids. 


ment  of  a  root  to  support  it. 


The  Bicuspids. 

1 2.  The  Upper  Bicuspids. — The  upper  l)icus])id  is  formed  by  duplica- 
:ion  of  the  primitive  cone  and  cnsp  in  a  transverse  direction  (Fig.  17,  a), 

\'iewed  from  the  standpoint  of  com- 
j)arative  dental  anatomy,  the  external 
cone  is  the  (•(intiic  cone — and  to  this  is 
added  the  internal  nr  hictispirJ  cone,  the 
tooth  being  a  double  canine.  The  bi- 
cuspids are  the  first  of  the  complex- 
teeth.  Tile  internal  cusp  is  formed 
by  the  raising  of  the  inner  primitive 
cusp  of  the  canine  and  the  devclop- 
The  distinctive  feature  of  the  architec- 
ture, therefore,  is  its  formation  from  two  cones,  and  this  makes  it  a 
weak  tooth  as  regards  its  mechanical  structure  and  resistance  to  mas- 
tication, for  the  binding  of  the  bases  of  the  cones  and  cusps  depends 
upon  the  connecting  power  of  the  two  marginal  ridges  (h,  b),  and  when 
these  are  destroyed  the  cones  readily  part  and  split  off. 

The  bicuspids  in  man  are  homologous  with  the  ])remolars  of  the 
quadrumana  and  other  lower  mammals.  They  succeed  and  displace  the 
molars  or  grinders  of  the  deciduous  set.  They  are  placed  next  after  the 
canines  in  both  jaws,  and  midway  between  the  cutting  and  grinding  teeth. 
Their  function  is  the  crushing  of  food  preparatory  to  mastication. 

The  upper  first  bicuspid  approximates  the  canine  on  the  distal  side. 
The  buccal  face  (c)  is  of  spear-head  shape,  similar  to  that  of  the 
canine.  This  is  more  apparent  in  some  lower  mammals  than  in  man,  in 
whom  it  is  much  reduced  and  rounded,  so  as  to  give  usually  the  apjiear- 
ance  of  a  long,  rounded  oval.  Tiie  buccal  cusp  (c)  rises  sharply  and 
prominently  from  the  lower  centre  of  the  face,  from  which  a  strong  ridge 
(fJ)  leads  up  to  the  cervical  border.  The  mesial  and  distal  lobes  (e,  e)  are 
rarely  conspicuous,  and  the  furrows  between  them  and  the  central  ridge 
lead  but  half  way  up  the  crown.  The  lobes  sometimes  have  prominent 
points   at   the  morsal  margins  which  in  lower  mammals  become  pro- 


THE  BICUSPIDS.  33 

nounced  cingules.  The  buccal  marginal  ridges  descend  from  the 
points  of  the  cusp  to  the  points  of  the  lateral  lobes.  The  distal  ridge 
is  usually  longer  than  the  mesial.  The  cervical  border  is  rounded  and 
oval  from  side  to  side. 

The  lingual  face  (/)  is  full  and  rounded,  more  or  less  straight  perpen- 
dicularly and  rounded  mesio-distally.  It  is  convex  in  both  directions. 
The  lingual  cusp  rises  over  it  full,  but  is  blunt  and  round ;  the  mar- 
ginal ridges  are  rounded,  not  angular,  and  curve  sharply  round  to  meet 
the  mesial  and  distal  marginal  ridges. 

The  mesial  face  (Fig.  18,  g)  is  wide  and  flat  transversely,  full  at 
the  morsal  surface  at  the  marginal  ridge,  which  is  prominent,  and  de- 
scending flat  to  the  cervix,  where 

a  depression  (h)  occurs  which  ex-  ^^^-  ^^■ 

tends  well  up  the  face. 

The  distal  face  is  of  similar 
form,  but  is  rather  more  convex 
and  the  portion  at  the  marginal 
ridge  more  prominent.  The  de- 
pression from  the  root  does  not 
extend  so  far  up  on  the  face.  ^  „,  , .       ., 

r  The  upper  bicuspids. 

The  morsal  surface  shows  an 
abrupt  change  from  that  of  the  canine  next  to  it,  as  it  presents  two 
distinct  cusps  or  points  instead  of  one.  One  cusp  is  on  the  buccal 
margin  (j)  of  the  crown,  and  one  on  the  lingual  {K),  and  they  are  named 
the  buccal  and  lingual  cusps.  The  buccal  cusp  is  sharp  and  prominent, 
and  is  not  unlike  the  single  canine  cusp.  The  lingual  cusp  is  broader 
and  more  rounded — indeed  it  is  preferable  to  term  it  a  tubercle. 

The  outline  of  the  morsal  surface  is  imperfectly  quadrate  and  is  bor- 
dered by  well-marked  marginal  ridges,  named  as  follows  : 

The  mesial  marginal  ridge  {J),  bordering  the  mesial  face  of  the  crown  ; 
the  distal  marginal  ridge  on  the  distal  side  (m),  the  buccal  marginal 
ridges  (w)  descending  from  the  point  of  the  buccal  cusp  to  meet  the  buc- 
cal terminations  of  the  distal  and  mesial  marginal  ridges  at  the  angle 
formed  by  the  junction  with  the  buccal  lateral  lobes  (o),  and  the  lingual 
marginal  ridges  (p),  descending  from  the  lingual  tubercle  to  meet  the 
lingual  termination  of  the  mesial  and  distal  marginal  ridges. 

The  triangular  ridges  descend  from  the  cusps  toward  the  centre  of 
the  tooth  and  unite  at  the  central  groove.  In  defective  teeth  they  do 
not  fuse,  leaving  a  fault  or  fissure  which  becomes  the  seat  of  caries. 
This  groove  or  sulcus  extends  from  one  lateral  marginal  ridge  to  the 
other  mesio-distally  (r)  and  widens  into  the  mesial  and  distal  sulci  at 
each  end.  The  triangular  grooves  (s)  run  from  the  mesial  and  distal 
sulci  toward  the  mesial  and  distal  angles,  dividing  the  marginal  ridges 


34  MACROSCOPIC  .\y.\TOMY  OF  Till-:   IlfWAX   TEETH. 

from  the  trianjjuhir.  Tlicy  also  Itccoinc  the  scat  of  caries  in  imperfectly 
formed  tooth. 

Tho  )i(rk  of  tlic  first  bicuspid  is  conii)rcssc(l  or  s])in(no-shaped  (t), 
the  enamel  line  risin*:;  on  the  hnecal  and  lingual  sides  and  dipping 
down  on  the  mesial  and  distal.  The  enamel  margin  tapers  otf  gradually 
on  to  the  root.  A  wide,  deep  de})rossion  usually  occurs  ((/)  on  tho  mesial 
side  of  the  neck,  leading  to  the  groove  on  the  root.  On  the  distal  face 
this  is  not  so  well  marked. 

Tho  root  is  much  Hattonod  mesio-tlistally,  with  a  decided  groove  ex- 
tending up  both  sides.  This  grooving  tends  to  cause  bifurcation  of  the 
root,  which  actually  occurs  in  one-third  of  the  cases,  especially  in  persons 
of  strong  build.  This  bifurcation  is  a  persistent  relic  of  lower  forms 
of  tho  premolars,  as  in  the  apes. 

The  root  canal  is  flat  at  the  neck,  and  nearly  always  bifurcated,  even 
when  the  root  is  not  separated.  This  is  readily  seen  by  holding  a  bicus- 
pid having  one  root,  up  to  the  light,  when  tho  central  portion  will  l)e  ob- 
served to  be  translucent.  Tho  usual  bifurcation  necessitates  the  search 
for  both  canals  in  every  case  in  treating  this  tooth. 

The  upper  second  bicuspid  {ic)  approximates  the  first  on  the  distal 
side,  and  is  similar  to  it  in  every  way,  except  that  it  is  usually  smaller  and 
more  rounded  in  all  directions.  Tho  sharp  features,  conspicuous  ridges, 
etc.  are  not  so  strongly  marked.  The  cusps  are  reduced,  the  ridges  more 
rounded,  and  the  morsal  face  more  flattened,  and  it  is  often  wrinkled. 
The  triangular  ridges  are  more  likely  to  be  united,  thus  making  the  crown 
stronger.  The  crown  is  thinner  mosio-distally.  The  neck  is  more 
rounded  or  oval. 

A  most  conspicuous  difference  is  in  the  7'oot,  which  is  narrower  labio- 
lingually,  is  more  rounded,  and  is  rarely  bifurcated.  It  is  sometimes 
cylindrical  or  cubical  in  form.  It  is  disposed  to  be  turned,  and  is  often 
crooked.     The  7-oot  canal  is  sinorle  and  readilv  entered. 

13.  The  Lower  Bicuspids. — Those  are  placed  next  after  the  lower 
canines  on  the  distal  side.  In  form  they  are  not  truly  bicuspid,  for  the 
first  is  unicuspid  and  the  second  is  tricuspid  in  the  pure  typal  forms ; 
but  they  are  arbitrarily  termed  bicuspids  on  account  of  their  position  as 
compared  with  the  u])])er  bicuspids,  which  are  typically  bicuspid. 

The  architectural  form  of  these  teeth  is  that  of  the  single  cone,  the 
crown  being  augmented  in  various  directions  by  the  addition  of  cin- 
gules  to  the  primitive  cusp. 

The  lower  first  bicuspid  is  a  well-formed  transitional  tooth,  for  it 
grades  from  canine  to  bicuspid  and  is  typically  composite.  It  more 
closely  resembles  a  canine  than  a  bicuspid  in  its  usual  form,  because 
the  inner  cusp  is  almost  suppressed  and  is  rarely  as  large  as  the  outer 
one  (Fig.  19,  «).     In  fact,  it  looks  like  a  canine  with  a  cingule  raised 


THE  BICUSPIDS. 


35 


upon  its  inner  face.  This  cusp  is  really  a  cingule,  for  it  is  rarely  raised 
to  the  full  height  of  a  cusp. 

It  varies  much  in  size  from  a  mere  point  on  the  basal  ridge  (6)  on 
through  various  degrees  of  development,  up  to  a  full  cusp  as  large  as 
the  buccal  cusp,  when  the  tooth  becomes  a  true  bicuspid.  The  tooth  is 
therefore  essentially  a  primitive  unicuspid  premolar,  of  the  form  of  this 
tooth  in  some  of  the  lower. primates. 

The  buccal  face  (c)  is  caniniform,  or  a  long  oval  in  outline  with 
the  cusp  rising  as  an  abrupt  point  above  it.  The  angle  of  the  junc- 
tion of  the  marginal  ridges  may  stand   out  prominently.     The   face 


The  lower  first  bicuspid. 

curves  markedly  toward  the  lingual  side,  so  that  the  buccal  cusp  becomes 
central  to  the  long  axis  of  the  tooth  («).  The  cervical  border  is  rounded 
at  its  margin  and  convex  from  side  to  side.     The  lobes  are  not  marked. 

The  Ungual  face  (d)  is  convex  from  side  to  side  and  straight  vertically, 
but  is  not  perpendicular,  as  it  is  directed  toward  the  lingual  side.  Its 
height  depends  upon  the  height  of  the  lingual  cingule,  which  varies  from 
a  mere  buccal  ridge  throiigh  various  degrees  up  to  the  full-sized  cusp. 

The  mesial  and  distal  surfaces  are  of  similar  form,  convex  from  side 
to  side  (a,  6)  slightly  flattened  at  the  cervical  border  and  flaring  out  to 
meet  the  full  marginal  ridges,  which  are  round  and  prominent.  The 
prominence  of  these  ridges  and  the  inward  inclination  of  the  lingual 
face  gives  the  crown  a  decided  bell  shape,  tapering  to  the  neck  (d). 

The  morsal  surface  (e)  is  peculiar  and  differs  from  every  other  tooth 
in  its  great  variability  and  the  extremes  which  it  may  present,  from 
being  a  full  bicuspid  to  a  mere  canine.  This  face  is  nearly  circular  in 
outline,  the  widening  of  the  lateral  surfaces  by  the  spreading  of  the 
marginal  ridges  (/,  /)  adding  to  the  width.  The  buccal  cusp  (g)  is  large 
and  prominent,  and  is  also  drawn  toward  the  centre  of  the  tooth  to 
accommodate  the  occlusion.  Sometimes  it  is  high  and  sharp  when  the 
lingual  cusp  is  reduced,  and  is  low  and  blunt  when  the  latter  is  en- 
larged,— appearing  to  have  an  inverse  ratio  in  size  to  the  inner  cusp. 
The  lingual  tubercle  or  cingule  varies  much  in  size,  from  a  mere  point 
on  the  basal  ridge,  above  the  cervical  border,  to  a  pronounced  cingule, 
a  larger  cingule,  a  small  cusp,  then  a  full  cusp,  the  basal  ridge    (A) 


36  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

being  raised  with  it.  The  ridges  are  the  mesial  and  distal  marginal 
ridges  (/,  /),  whieh  are  bowed  out  round  and  full  and  are  always  pro- 
nounced ;  the  buccal  marginal  ridges  (/,./'),  leading  down  irom  the  buc- 
cal cusp  to  form  an  angle  with  the  mesial  and  distal  marginal  ridges  ; 
the  basal  ridge,  when  the  lingual  eingule  is  lowered  (6) ;  and  the  tri- 
angular ridge  of  the  buccal  cusj),  whieh  is  always  large  and  when  the 
inner  tubercle  is  reduced  leads  down  as  a  high  central  eminence.  The 
lingual  eingule,  as  a  rule,  possesses  no  triangular  ridge. 

The  central  groove  usually  crosses  the  central  ridge  {h),  but  not 
always,  being  often  bowed  around  its  lower  termination.  Sometimes  the 
ridge  is  crossed  by  a  sulcus.  The  groove  terminates  in  a  sulcus  at  each 
end,  with  slight  triangidar  grooves  branching  up  on  the  buccal  cusp. 
Tile  neck  is  usually  oval  on  section,  being  much  constricted,  the  crown 
flaring  upward  from  the  cervical  portion,  giving  the  crown  the  well- 
known  bell  shape.  The  enamel  line  dips  i)ut  slightly,  being  usually 
level  on  all  four  sides.  The  buccal  border  sometimes  presents  a  prom- 
inent ridge. 

The  i-oot  is  single,  long,  ta})ering  and  may  be  nearly  round,  but  is 
usually  flattened  mesio-tlistally.  It  is  sometimes  thick  the  greater  part 
of  its  length,  and  terminates  in  an  abrupt,  round,  blunt  apex  (c,  d).  It 
is  very  liable  to  be  crooked.  It  is  rarely  bifurcated  and  does  not  pre- 
sent grooves  on  its  lateral  faces. 

The  puljj  canal  is  constricted  and  flattened  at  the  neck,  and  the  back- 
ward inclination  of  the  teeth  makes  it  difficult  to  enter.  The  possibility 
of  the  root  being  crooked  and  the  peculiarity  of  its  anatomical  rela- 
tionships' also  increase  the  uncertainty  of  treatment,  which  makes  the 
root  canals   of  the  lower  bicuspids  difficult  to  deal  with. 

The  lower  second  bicuspid  aj)proximates  the  first  on  its  distal  side. 
It  resembles  the  first  as  regards  the  general  form  of 
Fig.  20.  ^jjg  crown,  its  tapering  bell  shape,  the  constriction  of 

the  neck,  and  the  shape  of  the  root.  In  all  these 
features  there  is  little  diffi?rence  between  these  teeth, 
and  the  description  of  the  first  will  apply  also  to  the 
second  bicuspid. 

The  moi\mI  surface  (Fig.  20),  however,  differs  very 
il  materially  from  that  of  the  first.     This  is  circular  in 

The  morsai  surface  of     outline  like  the  first,  and  the  buccal  cusp  is  full  and 

the  lower  secoQcl  bi- 

cuspid.  rounded  (a),  but  the  inner  cusj)  is  divided  by  a  groove 

(6)  running  over  it,  into  two  parts,  so  that  it  is  really 

divided  into  two  tubercles.    This  makes  the  lower  second  bicuspid  in  its 

typal  form  a  tricuspid  tooth  ;  so  that  it  diffi'rs  from  the  lower  first,  which 

has  but  one  cusp,  and  from  the  others,  which  have  but  two  cusps.     The 

•  See  page  606,  Chapter  XXL,  on  Extraction  of  Teeth. 


THE  MOLARS.  37 

lingual  tubercles  vary  much  in  size,  so  that  one  may  be  suppressed  and 
the  tooth  seem  bicuspid.  The  mesial  lingual  tubercle  (c)  may  be  of 
large  size  and  be  developed  at  the  expense  of  the  distal  (rf) ;  this  may 
be  a  mere  cingule  on  the  distal  marginal  ridge  and  appear  on  the  distal 
side,  but  it  is  always  present. 

The  morsal  groove  (e)  is  triangular  in  design,  passing  between  each 
of  the  three  tubercles.  A  well-marked  triangular  ridge  descends  from 
each  of  the  cusps. 

The  tricuspid  form  of  the  morsal  surface  of  this  tooth  is,  of  course, 
a  reproduction  of  the  trituberculate  premolars  of  the  lower  primates, 
and  of  still  lower  mammals,  although  the  triangular  form  of  the  crown 
is  lost  in  man. 

The  Molars. 

14.  The  Tuberculate  Teeth. — Molar  teeth  appear  early  in  the  scale 
of  vertebrate  life  ;  mere  crushing  teeth  are  found  in  fishes,  and  slightly 
tuberculate  teeth  in  the  reptiles.  The  grinders  are  of  simple  form  in  the 
lowest  mammals.  The  Bruta  have  simple,  flat-crowned  molars,  which 
are  undifferentiated  and  used  merely  for  crushing.  Tuberculate  molars 
appeared  early  in  the  placental  mammalia,  the  trituberculate  molars  being 
found  in  numerous  fossil  species,  which  are  the  typal  form  and  forerunners 
of  the  tuberculate  molars  in  the  higher  mammalia.  The  simple-crowned 
tooth  with  a  single  tubercle  (haplodont,  Cope),  becomes  duplicated  and 
doubled,  with  a  crown  supporting  several  tubercles  [bunodont).  The 
transition  from  simple  to  complex  teeth  is  accomplished  by  the  repeti- 
tion of  the  type  in  different  directions  and  the  addition  of  cusps  and 
roots  both  laterally  and  longitudinally  of  the  jaw.  The  upper  molar  is 
formed  by  the  addition  of  the  third  cusp  to  the  bicuspid  type  and  has 
three  roots,  which  support  three  or  four  tubercles.  Lower  molars  con- 
sist of  four  cones  which  support  four  or  five  tubercles.  The  lower  mo- 
lar is  therefore  the  more  complex  tooth.  The  bicuspid  is  more  complex 
than  the  canine,  the  upper  molar  than  the  bicuspid,  the  lower  than  the 
upper  molar. 

The  molar  teeth  of  man  are  bunodont  in  form,  i.  e.  they  have  simple 
rounded  tubercles  on  the  grinding  face.  They  are  of  simple  and  primi- 
tive type,  and  indeed  are  most  like  the  molars  of  the  bears  and  other 
omnivorous  animals.  They  are  not  highly  specialized  like  those  of  the 
carnivora  on  the  one  hand  with  high  sharp  blades  for  cutting  flesh,  nor 
like  those  of  the  herbivora  on  the  other,  which  are  extended  laterally  for 
grinding  tough  vegetable  fibre.  They  are  of  low  organization  as  regards 
their  functional  development. 

The  molars  in  man  are  twelve  in  number,  three  on  each  side  of  each 
jaw,  and  are  placed  at  the  rear  of  the  arch,  opposite  the  strong  triturat- 


38  MACROSCOriC  ANATOMY   OF  TIIF.    11  I'M  AS   TF.F.TII. 

iiif  nuisclcs,  lor  the  purpose  of  cnisliinii;  ;ni(l  niMsticatiiiir  food.  They 
aro  important  factors  in  alimentation  and  contribute  to  tlie  lunction  of 
digestion  hy  jireparino-  iood  for  the  stomach.  Their  loss  impairs  this 
function  seriously  and  leads  to  deranp;cment  of  the  stomach  hv  over-tax- 
ing: it  with  imperfectly  masticated  food-suhstances. 

15.  The  Upper  Molar. — The  typical  upper  molar  is  lormed  hy  the 
fusion  of  three  cones,  as  is  plainly  observed  in  the  tliice  roots  and  tiie 
three  tubercles  (Fig.  21,  A).  The  tricuspid  molar,  therefore,  is  a  primi- 
tive form,  and  is  occasionally  seen  in  man,  the  normal  firm  being  (piadrl- 
tuberculate.  The  fourth  additional  cusp,  the  disto-lingual  {b),  is  merely 
a  supplemental  cusp  added  to  the  crown.  An  u]>per  molar  is,  there- 
fore, composed  of  three  tubercles,  and  a  cingule  which  has  not  yet 
developed  a  root  to  sujiport  it.  The  trituberculate  molar  is  the  primitive 
form  of  this  tooth,  the  ((uadrituberculate  appearing  later,  and  is  found  in 
only  a  few  living  forms,  as  some  of  the  lemurs  and  the  insectivorous 
and  carnivorous  mammalia.  In  man  there  is  sometimes  a  reversion  of 
the  up])er  molar  to  the  trituberculate  form,  which  is  a  marked  degeneracy 
in  the  form  of  this  tooth.  In  an  analysis  of  this  tooth,  therefore,  the 
mesio-buccal  tubercle  (c)  is  the  canine  cusp  ;  the  mesio-lingual,  the  bicus- 
pid cusp  {d)  ;  the  disto-buccal,  the  molar  cusp  (e),  and  the  disto-lingual 
is  but  a  supplemental  cusp, — it  is  not  a  true  cusp,  as  it  has  no  root  to 
support  it. 

The  architecture  of  the  upper  molar  presents  some  interesting  features. 
We  observe  that  the  crown  is  in  a  general  way  a  geometrical  form,  a 
cube  (/),  when  perfect  and  symmetrical.  It  is  suggestive  of  symmetry, 
but  wdien  taken  with  the  root  form  is  not  quite  perfect,  for  it  is  sup- 
ported on  three  roots  instead  of  four  to  correspond  with  the  four  tuber- 
cles at  the  four  corners.  So  it  lacks  the  "  harmony  of  adequate  sup- 
port," which  is  a  cardinal  principle  in  architecture.  But  the  crown 
separately  is  a  symmetrical  form,  a  cube,  although  the  angles  are  rounded 
off  and  the  corners  and  points  are  toned  down  and  not  acute.  We  no- 
tice that  there  are  four  strong  columns,  one  at  each  of  the  four  corners 
(ff).  They  are  connected  on  the  four  sides  by  the  marginal  ridges  acting 
as  strong  connecting  arches  (h).  These  arches  are  related  to  the  col- 
umns of  the  crown,  and  both  are  impressively  proportioned.  The  cusps 
may  be  likened  to  the  capitals  of  the  columns,  and  the  descending  mar- 
ginal and  triangular  ridges  to  the  cornice,  gathered  together  to  form  the 
capitals.  The  triangular  ridges  may  be  considered  girders  (i),  bind- 
ing the  four  together  and  also  bracing  the  square  obliquely.  Or,  the 
four  triangular  ridges  running  to  the  centre  may  be  regarded  as  half- 
arches  or  buttresses,  supporting  the  roof  vault, — the  grinding  face. 
Other  elements  could  be  marked  out  in  an  architectural  study  of  the 
crown  of  this  tooth,  showing  its  beautiful  design  and  symmetry. 


THE  MOLARS. 


39 


The  upper  first  molar  approximates  the  second  bicuspid  on  its  distal 
side.  There  is  a  marked  and  abrupt  change  in  form,  as  the  molar  has 
double  the  number  of  cusps  of  the  bicuspid, — being  formed  like  two 
bicuspids  fused  together.  The  four  tubercles  mean  an  extension  of  sur- 
face and  a  further  adaptation  to  functional  requirements.  The  crown 
is  large  and  cubical  in  form,  and  more  or  less  rounded. 


Fig.  21. 


A  e 


Architectural  diagram. 


s  q 
The  upper  molar. 


The  buccal  face  (k)  is  wide  and  rounded.  It  is  twice  the  width  of 
the  bicuspids.  It  is  broadest  at  the  morsal  margin,  narrowing  upward  to 
the  cervix,  where  it  is  widely  rounded  or  arched.  A  vertical  depression, 
the  buccal  groove  (I),  extends  from  the  cervical  border  to  the  morsal 
margin,  dividing  the  face  into  two  oblong  rounded  eminences,  the  mesial 
and  distal  buccal  lobes  {m  m). 

The  lingual  face  {n)  is  more  rounded  than  the  buccal,  the  cervical  por- 
tion being  the  most  convex  (o),  the  mesial  and  distal  sides  being  depressed 
toward  the  single  lingual  root.  The  morsal  half  is  divided  by  the 
lingual  groove  (q),  which  descends  over  the  lingual  marginal  ridge  be- 
tween two  lobes,  the  mesial  (?■)  and  distal  (p),  which  are  usually  much 
rounded.  The  morsal  half  of  the  face  curves  toward  the  grinding  sur- 
face. The  mesial  lobe  sometimes  presents  the  lingual  cingule  (s),  a 
sort  of  fifth  tubercle  of  greater  or  less  size.  A  groove  branches  from 
the  lingual  groove  and  extends  over,  between  the  cingule  and  crown. 

The  mesial  face  {T)  is  flat  longitudinally,  descending  from  the  marginal 
ridge   to  the  cervix  in  a  nearly  straight  line.     Bucco-linguallv  it  is 


40 


MACROSCOPIC  .l.V.17Y>.V}'   OF  THE  HUMAN  TEETH. 


convex,  nearly  flat  at  the  marginal  ridge,  aii<l  rounded  at  the  cervix, 
heing  depressed  toward  the  lingual  root.  Sometimes  a  depression  from 
the  l)ifur('ation  of  the  mesio-buceal  and  lingual  roots  extends  partway 
up  on  the  face  (u). 

The  distal  face  is  similar  to  the  mesial  except  that  it  dips  more 
toward  the  cervix,  and  is,  perhaps,  more  rounded  toward  the  lingual 
root. 

The  morsal  surface  (Fig.  22)  is  the  most  important  part  of  this  tooth, 
and  shows  features  that  make  it  interesting  and  unique.     The  abrupt 


Fig.  22. 


.7         / 


i1     h      j       <• 

The  morsal  surface  of  the  upper  first  molar. 

change  from  the  bicuspid  form  is  notable,  for  there  are  presented  four 
cusps,  a  doubling  of  the  number ;  the  outline  of  this  face  presents  a 
square  form  with  tubercles  at  each  corner,  the  mesio-buccal  («),  the 
disto-buccal  (6),  the  mesio-lingual  (c),  and  the  disto-lingual  (d) ;  the  lat- 
ter is  erratic  and  may  be  either  pronounced  or  quite  reduced  in  size. 

There  are  four  marginal  ridges — the  mesial  {e),  buccal  (/),  distal  (<7) 
lingual  {h),  the  oblique  (i),  and  the  four  triangular  ridges  (j).  The  oblique 
ridge  connects  the  mesio-lingual  with  the  disto-buccal  tubercle  and  is 
really  the  remnant  of  the  marginal  ridge  of  the  tricuspid  molar ;  the 
fourth  cusp,  the  disto-lingual,  being  raised  up  on  the  disto-lingual  side. 
The  four  triangular  ridges  descend  from  the  four  tubercles  toward  the 
centre  of  the  tooth,  the  oblique  ridge  being  formed  by  the  fusion  of  the 
triangular  ridges  of  the  mesio-lingual  and  disto-buccal  cusps. 

There  are  two  fossse  {k),  one  mesial  and  the  other  distal  to  the  oblique 
ridge.  Sometimes  the  latter  is  cut  by  a  groove  or  sulcus  (l)  which 
extends  from  the  mesial  to  the  distal  fo.ssa.  Sometimes  by  the  reduction 
of  the  disto-lingual  lolx'  and  cusp,  the  mesial  fossa  is  extended  and 
becomes  central  to  the  crown.  A  groove  extends  from  the  mesial  fqgsa 
over  the  buccal  marginal  ridge  (///)  cjuite  on  to  the  buccal  face,  dividing 
the  mesial  from  the  distal  buccal  lobes.  A  groove  also  extends  over 
the  lingual  marginal  ridge  (n)  down  upon  the  lingual  face,  dividing  the 
lingual  lobes.  When  this  groove  becomes  a  fissure,  caries  ensues  and 
the  disto-lingual  cingule  readily  breaks  away,  this  cingule  being  a  weak 
feature  in  the  mechanical  design  of  this  tooth  ;  cutting  the  distal  mar- 
ginal ridge  also  weakens  this  cusp.    The  triangular  grooves  branch  from 


THE  MOLARS.  41 

the  two  fossae  on  to  the  cusps,  dividing  the  triangular  from  the  marginal 
ridges. 

The  neck  of  this  tooth  is  of  rounded  rhomboid  form  on  section  (o), 
widest  at  the  buccal  side.  The  enamel  is  almost  level  on  all  four  sides, 
dipping  downward  slightly  on  the  mesial  and  distal.  A  depression 
occurs  at  the  bifurcation  of  the  buccal  roots,  and  an  inward  inclination 
on  the  mesial  and  distal  sides. 

The  roots  are  three  in  number  (Fig.  21),  two  on  the  buccal  side, 
which  are  small  and  flat  or  round,  and  one  on  the  lingual  side,  which  is 
large  and  rounded.  The  roots  are  usually  separated,  but  may  be  found 
united,  by  a  septum  of  cementum,  in  various  directions.  The  mesio- 
buccal  root  is  the  larger  of  the  two  buccal  roots,  and  forms  a  second 
turning-point  or  spring  of  the  arch.  All  the  roots  are  slightly  bent 
and  may  be  very  crooked. 

The  jpulp  chamber  branches  into  three  canals,  one  in  each  root.  The 
lingual  canal  is  large  and  open  and  is  readily  entered.  The  canals  of  the 
two  buccal  roots  are  small  and  fine,  and,  with  the  possibility  of  crooked- 
ness in  the  roots,  present  the  most  difficult  problems  as  to  treating  and 
filling  found  in  the  whole  denture. 

The  upper  second  molar  is  similar  to  the  first  in  some  respects  but 
very  different  in  others.  It  is  rather  smaller,  is  not  usually  full  and 
square,  but  disposed  to  become  rhomboid  in  form  (Fig.  23,  a,  b),  by 
disto-mesial  compression. 

The  buccal  face  is  similar  to  that  of  "^ 

the  first  molar,  and  the  same  description       /'-^'■^T^     fl  i  w^     a  (i    /i 
will   apply  to   it.      If  any  difference  is      IrngM    I  it   %      (l/irjf 
fiDund  it  is  that  the  face  is  strongly  com-     \^^0     |  Jp    I      wW^W 
pressed  from  front  to  back,  and  the  disto-       /iw     JliP'Tl     JMi% 
lingual  cusp  is  more  reduced  as  a  con-      ijmM   w  %    M    I    t    'l 

The  lingual  face  (c)  is  different  from  *„^       '^  f'    ,  ^ 

^  •'  ^  '  The  upper  second  molar. 

that  of  the  first  molar  in  that  by  the  sup- 
pression of  the  disto-lingual  tubercle  {d)  and  the  distal  lobe,  the  mesio- 
lingual  lobe  is  enlarged  so  that  it  occupies  the  entire  face,  which  is  full, 
rounded,  and  convex  (e).  It  is  rarely  divided  into  two  lobes  as  in  the 
first  molar,  owing  to  the  enlargement  of  the  mesial  lobe  and  the  pushing 
backward  of  the  oblique  ridge,  which  throws  the  lingual  groove  on  to 
the  disto-lingual  angle  {<£) ;  or  the  groove  may  be  absent  altogether. 

The  mesial  and  distal  faces  are  similar  in  form  to  those  of  the  first 
molar,  being  perhaps  more  flattened. 

The  morsal  face  is  similar  to  that  of  the  first  molar,  except  that  the 
tubercles  are  less  pronounced  and  the  distal  ones  are  reduced  in  height 
to  accommodate    the  upward    curve  of  the  line    of  occlusion    at  this 


42 


MACROSCOPIC  ANATOMY  OF  THE  HUMAN   TEETH. 


|)oiiit.  The  (listo-linffual  oiiifrulc  is  snialltT  than  that  upon  the  first 
molar,  and  is  often  hardy  marked.  This  throws  the  oblique  ridge  more 
to  the  distal  side  and  enlart^es  tlie  mesial  f(»ssa.  The  various  grooves  are 
the  same  as  on  the  Hrst  molar,  except  that  one,  the  lingual,  may  be  lost. 

The  neck  is  less  regular  in  outline  than  that  of  the  Hrst  molar,  as  the 
crown  varies  so  mueii  in  shape.  It  is  more  flattened  mesio-distally  and 
ilepressed  toward  the  roots. 

The  roots  are  the  same  in  number  and  general  form  as  in  the  first 
molar,  but  spread  less  and  are  more  irregular  in  form.  They  may  con- 
verge or  be  crooked,  or  may  be  fused  together.  This  makes  the  pulp 
canals  more  difficult  to  treat.  Sometimes  the  three  roots  are  completely 
fused,  as  in  the  third  molar,  and  the  canals  may  coalesce  ;  or  the  canals 
of  the  two  buccal  roots  may  run  into  one.  The  irregularity  and  uncer- 
tainty of  the  form  of  the  roots  make  this  tooth  difficult  to  deal  with  in 
treatinc;  its  root  canals. 

10.  The  Lower  Molars. — The  lower  first  molar  ajiproximates  the 
lower  second  bicuspid  on  its  distal  side.  It  is  the  first  of  the  true  grind- 
ers of  the  lower  jaw  and  the  largest  tooth  in  the  dental  series.  Unlike 
the  upper  molars  the  transverse  diameter  is  less  than  the  mesio-distal. 
The  greater  width  is  found  across  the  base  of  the  disto-buccal  tubercle. 
The  crown  is  s(juare  or  trapezoidal  in  form,  de])ending  on  the  size  of  the 
fifth  tubercle.  Being  quinquituberculate,  the  crown  is  broadened  by  the 
multicuspid  grinding  face.  The  buccal  face  is  inclined  toward  the  centre 
of  the  tooth,  for  its  morsal  half,  to  accommodate  the  occluding  teeth. 

Architecturally,  the  tooth  is  formed  of  four  cones  (Fig.  24,  A),  and 


Architectural  diagram. 

g 


B 

The  lower  tirst  molar. 

mav  be  roughly  divided  into  four  quarters.     There  are  four  primitive 
cones  with  their  tubercles  and  one  cingule  in  the  structure. 


THE  MOLARS.  43 

The  morsal  surface  (B)  is  trapezoidal  in  outline,  the  buccal  line 
being  the  longest.  The  buccal  angles  are  acute,  while  the  lingual 
are  rounded  and  obtuse. 

There  are  five  tuber-des,  two  on  the  lingual  margin  and  three  on  the 
buccal.  They  are  named  the  mesio-buccal  (c),  median  buccal  (d),  disto- 
buccal  (e),  disto-lingual  (/),  and  mesio-lingual  (g).  These  tubercles  are 
less  obtuse  and  more  rounded  than  those  of  the  other  grinding  teeth,  the 
mesio-buccal  usually  being  the  largest,  the  others  are  not  so  prominent, 
rarely  raised  and  sharp. 

The  ridges  are :  the  marginal  ridges — buccal,  distal,  lingual,  and 
mesial — and  the  five  triangular  ridges  descending  from  the  five  tuber- 
cles toward  the  centre  of  the  tooth. 

The  grooves  and  sulci  upon  the  morsal  surface  are  very  irregular.  A 
deep  sulcus  traverses  the  face  from  the  mesial  to  the  distal  marginal 
ridge.  A  groove  runs  off  toward  the  lingual  side,  dividing  the  lingual 
cusps  (i),  sometimes  cutting  the  lingual  marginal  ridge,  but  rarely 
reaching  over  on  the  lingual  face.  A  groove  runs  toward  the  buccal 
side,  dividing  the  mesio-buccal  from  the  median  tubercle  (j),  cutting 
the  marginal  ridge  and  extending  over  quite  on  to  the  buccal  face.  This 
groove  often  becomes  the  seat  of  caries  owing  to  the  enamel  structure 
being  faulty.  Another  groove  extends  toward  the  disto-buccal  angle  (k), 
dividing  the  median  from  the  disto-buccal  tubercle,  and  rarely  extends 
over  on  to  the  buccal  face.  A  groove  may  extend  distally  cutting  the 
distal  marginal  ridge  (I),  and  one  mesially  cutting  the  mesial  marginal 
ridge  (m),  but  these  are  not  usually  marked.  The  triangular  groove  run- 
ning up  on  each  side  of  the  triangular  ridges  (n)  divides  these  from  the 
marginal  ridges.  Supplemental  grooves  may  divide  the  triangular  ridges 
again.  The  pits  at  either  end  of  the  sulcus  may  become  the  seat  of  caries 
through  faulty  formation. 

The  buccal  face  (C)  is  an  irregular  trapezoid  in  form,  the  morsal  margin 
being  longest ;  the  mesial  and  distal  sides  converge  toward  the  cervical 
border,  which  is  rounded.  The  morsal  margin  is  broken  by  the  three 
tubercles  rising  upon  it.  The  buccal  face  is  convex  in  all  directions, 
that  from  the  morsal  to  the  cervical  borders  being  the  most  marked 
owing  to  the  morsal  half  converging  toward  the  centre  of  the  tooth. 
The  buccal  groove  (o)  leading  over  from  the  morsal  face,  divides  the 
face  into  two  lobes  which  are  full  and  rounded.  Sometimes  the  disto- 
buccal  groove  cuts  off  another  lobe,  thus  making  three  lobes  on  the  buccal 
face.  These  grooves  sometimes  lead  to  the  cervical  border,  but  usually 
terminate  in  the  middle  of  the  face  in  a  pit,  which  may  become  the  seat 
of  caries  through  faulty  formation  of  the  enamel. 

The  lingual  face  (D)  is  wide,  rounded,  smooth  and  convex,  rather 
straight  perpendicularly,  leaning  in  the  lingual  direction.     It  forms  a 


44  MArROSCnPIC  ANATOMY  OF  THE  TTIWAX  TEKTJI. 

slmrj)  autrlf  with  the  niorsal  surface,  wliicli  is  siirmoiiiitcd  with  two 
tiilxTcU's.  Sometimes,  l)iit  rarely,  the  lintrnal  ^move  jiasses  over  on  to 
tliis   face. 

The  iiirsid/  and  disfa/  fdcr.^  (n)  are  wide  and  flattened  transversely, 
hut  convex  vertically.  They  are  trajnzoidal  in  outline,  the  niorsal 
border  bein^  longer.  The  cervical  border  is  more  convex,  and  dips 
toward  the  neck  of  the  tooth. 

The  neck  (f)  is  very  regidar  in  outline  and  contour.  It  is  approxi- 
mately sijuare  with  all  four  sides  depressed  in  the  centres.  The  mesial 
and  distal  are  depressed  at  the  origins  of  the  grooves  leading  down 
upon  the  roots ;  the  lingual  and  buccal  are  depressed  at  the  bifurca- 
tion of  the  roots,  the  depression,  which  is  w'ide  and  deep,  extending  up 
on  to  the  neck,  especially  upon  the  buccal  side.  The  enamel  line  is 
(juite  irregular,  dipping  down  on  the  lingual  and  buccal,  and  leading 
well  up  on  the  mesial  and  distal  sides. 

The  rootx  are  two  in  number,  placed  with  their  longer  diameter  trans- 
versely to  the  jaw.  They  are  wide  bucco-lingually,  and  flat  and  narrow 
disto-mesially,  being  situated  distally  and  mcsially  to  the  crown.  The 
])osterior  is  formed  of  the  two  posterior  cones,  and  the  anterior  of  the 
two  anterior  cones  (A).  This  is  plainly  shown  in  the  formation  of  the 
roots,  which  are  grooved  botli  distally  and  mesially,  and  in  the  tendency 
to  bifurcation,  which  sometimes  actually  occurs.  They  divide  close  to 
the  crown,  so  that  the  grooves  of  bifurcation  extend  well  up  on  the 
neck.  The  distal  root  is  thicker  and  more  rounded  than  the  mesial, 
the  latter  being  more  flattened,  with  the  grooves  deeper,  and  it  is  more 
often  bifurcated.     Both  are  deflected  from  the  median  line. 

The  root  canal  is  shaped  like  the  roots,  with  two  main  branches. 
The  distal  branch  is  the  larger,  being  round  and  ojien,  as  the  root  is  more 
rounded.  The  mesial  branch  is  flat  and  spindle-shaped,  being  diflicult 
to  enter,  and  usually  having  two  sub-branches  following  the  buccal  and 
lingual  divisions  of  the  root.  These  sub-branches  are  small  and  hair- 
like aud  troublesome  to  enter. 

The  lo-wer  second  molar  (Fig.  25)  differs  from  the  first  in  many 
respects.  It  is  of  the  same  general  form,  but  is  more  quadrangular,  as 
it  has  but  four  tubercles.  It  is  more  rounded  and  symmetrical  than  the 
first,  the  four  cones  and  four  primitive  tubercles  being  well  marked. 
The  absence  of  the  fifth  tubercle  leads  to  most  of  the  differences  between 
the  second  and  the  first  molar. 

The  morsal  face  (c)  has  but  four  tubercles,  one  at  each  corner  of  the 
face,  differing  from  that  of  the  first  molar,  which  has  five.  The  fifth 
tubercle  rarely  appears  in  the  higher  races  of  mankind,  but  is  some- 
times found  in  the  low  and  savage  races,  and  occurs  regularlv  in  the 
apes.     It   is  n(^t  uncommon  in  the  negro,  but  is  absent  as  a  rule  in 


THE  MOLARS. 


45 


the  European  races.  The  tubercles  are  symmetrical,  rounded  and 
obtuse,  the  lingual  being,  however,  sharper  than  the  buccal. 

The  sulci  describe  a  cruciform  shape,  separating  the  four  tubercles 
symmetrically  from  each  other.  The  buccal  groove  sometimes  continues 
on  to  the  buccal  face,  rarely  to  the  lingual.  The  triangular  grooves 
run  up  on  the  morsal  triangular  ridges.  The  marginal  ridges  are  well 
marked,  the  mesial  and  distal  being  often  divided  by  grooves.  The 
triangular  ridges  are  usually  well  marked,  leading  to  the  centre  of  the 
tooth.     They  are  full  and  strong. 

The  buccal  face  (d)  is  convex  and  of  more  regular  form  than  that 
of  the  first  molar.     It  is  divided  into  two  lobes  (e,  e)  by  the  buccal 


Fig.  25. 


h       h 
The  lower  second  molar. 


groove  (d),  which  is  rarely  deep.  A  pit  is  often  found  in  the  centre 
of  the  face,  which  may  become  the  seat  of  caries.  The  face  is  curved 
toward  the  centre  of  the  tooth,  as  in  the  first  molar. 

The  lingual  face  is  similar  to  that  of  the  first  molar,  but  may  be  more 
rounded  toward  the  morsal  border.  It  is  symmetrically  convex  in  both 
directions. 

The  mesial  and  distal  faces  (/)  are  similar  to  those  of  the  first  molar 
except  that,  the  crown  being  smaller,  they  may  be  more  perpendicular, 
but  are  well  rounded. 

The  neck  (g)  is  more  regularly  formed  than  that  of  the  first  molar, 
the  margin  of  the  enamel  line  being  quite  as  irregular.  It  may  be  more 
constricted. 

The  roots  (A,  h)  are  similar  to  those  of  the  first  molar,  but  are  more 
rounded  in  shape,  are  usually  crooked,  and  on  that  account  difficult  to 
treat. 

The  root  canals  are  similar  to  those  of  the  first  molar,  but  the  tend- 
ency to  crookedness  renders  treatment  quite  difficult.  The  direction 
of  irregularity  of  form  is  so  uncertain  that  no  rule  can  be  applied  to  it. 

17.  The  Third  Molars. — The  upper  and  lower  third  molars  can  best 
be  described  together,  on  account  of  their  similar  eccentricities.  They 
are  very  irregular  as  to  the  time  and  to  the  frequency  of  their  appearance 
in  civilized  man.     About  one-half  of  the  individuals  of  European  races 


4fi  MACROSCOPIC  Ay  ATOMY  OF  THE   ffl'MAX   rKETU. 

onipt  tlicin  at  the  normal  period,  /.  c  seventeen  to  twenty-one  years  of 
atjc.  In  one-fourth  th(\v  erupt  at  irregular  intervals  to  the  thirtieth 
vear,  and  in  the  remainder  they  may  appear  later,  or  the  first,  seeond, 
third,  or  all  of"  them,  may  he  absent  alto»;'eth('r.  In  one  series  of  inrty 
adult  skulls  observed,  twelve  had  one  or  more  absent.  The  absence  and 
othei-  erratic  peculiarities  of  these  teeth  sometimes  seem  to  be  hereditary 
and  can  be  traced  in  families  through  several  generations. 

This  tooth  is  often  reduced  in  size  and  may  be  a  mere  peg  (Fig.  26,  a). 
it  is  of  very  irregular  form  in  civilized  races,  but  is  as  large  and  as  well 

formed  as  the  other  molars  in  most 
races  low  in  the  ethnological  scale. 
The  contraction  of  the  jaws  through 
disuse  has  much  to  do  with  the  mal- 
development  of  this  tooth,  and  it  is 
often  so  cramped  for  room  as  to  pro- 
duce distressing  irritation  which  ne- 

The  upper  third  molar.  .  .  .  _ 

cessitates  its  removal.  Impaction 
and  malposition  of  the  third  molars  render  them  difficult  of  extraction 
and  are  the  fruitful  source  of  many  serious  lesions.  (See  the  chapter 
on  Extraction  of  Teeth.) 

The  upper  third  molar  is  more  or  less  similar  to  the  other  upper 
molars  when  perfect  and  well  developed,  but  it  is  very  erratic  as  to  form 
and  structure. 

This  tooth,  when  well  formed,  is  of  trituberculate  form  (h),  the 
disto-lingual  cingule  being  suppressed.  This  cingule  diminishes  grad- 
ually from  the  first  molar,  in  which  it  is  well  formed,  to  the  second, 
where  it  is  reduced,  then  to  the  third,  where  it  is  almost  or  entirely 
absent.  The  oblique  ridge  thus  becomes  the  posterior  marginal  ridge 
(e),  as  in  the  typical  trituberculate  molar.  The  three  tubercles  are 
reduced  and  rounded.  The  sulci  usually  degenerate  into  fissures,  as 
the  formation  of  this  tooth  is  notoriously  faulty.  The  enlarged  mesial 
fissures  thus  become  the  seat  of  extensive  caries. 

The  hitccal  face  resembles  that  of  the  first  and  second  molars,  but  is 
more  rounded. 

The  lluf/ual  f((ce  (d)  is  full  and  rounded,  with  but  a  single  lobe,  owing 
to  the  reduction  or  absence  of  the  disto-lingual  tubercle. 

The  mexiaJ  f<toe  (e)  is  similar  to  that  of  the  second  molar,  but  reduced, 
and  the  distal  face  is  round  and  short,  as  no  tooth  succeeds  it  in  the  rear. 

The  neck  is  constricted  and  tapers  toward  the  conate  roots.  It  is  of 
a  rather  rounded  triangular  shape. 

The  three  rooU  of  the  upper  molars  are,  in  the  third,  usually  more 
blunt,  conate,  short  in  form,  and  may  curve  backward.  In  lower  races 
and  sometimes  in  individuals  having  strong  osseous  organizations,  the 


THE  MOLARS. 


47 


The  lower  third  molar. 


typical  three  molar  roots  are  found.  Sometimes  there  are  multiple 
roots,  which  are  likely  to  be  curved  in  various  directions  and  may 
have  decided  hooks. 

In  the  large  conate  root,  the  root  canals  usually  coalesce,  but  in 
cases  in  which  the  root  is  divided  there  will  also  be  division  of  the 
pulp  chamber. 

The   lower   third  molar   is  similar    to   the  other  lower  molars  in 
general  form  (Fig.  27,  a),  but  is  probably  not  so  erratic  and  not  subject 
to  such  extreme  variations.     The  crown  is 
quadrangular  in  section,  the  angles  rounded. 

On  the  morsal  face  (b),  there  are  four 
principal  tubercles  as  in  the  second  molar, 
but  this  may  be  supplemented  by  the  ex- 
tension of  the  disto-marginal  ridge  into  a 
cingule  or  heel  (c).  This  heel  is  rather 
erratic ;  it  may  be  large  or  small,  thus 
modifying  the  size  of  the  morsal  sur- 
face. Sometimes  the  face  is  wrinkled  and,  like  this  tooth  in  the 
orang  utan,  the  sulci  exhibit  the  cruciform  shape  similar  to  that  of  the 
second  molar.  The  many  grooves  leading  away  from  the  main  sulcus  may 
be  imperfect  and  become  the  seat  of  caries.  The  buccal  groove  running 
from  the  morsal  on  to  the  buccal  face  (a)  is  very  subject  to  imperfection. 

The  four  lateral  faces  are  similar  to  those  of  the  second  molar,  except 
that  the  distal  is  more  convex  and  full,  and  often  very  prominent  if  the 
fifth  cingule  is  well  developed. 

The  neck  is  of  similar  shape  to  that  of  the  second  molar. 

The  roots  are  similar  to  those  of  the  other  loAver  molars,  but  generally 
smaller  as  compared  with  the  crown  (d).  They  are  usually  divided  like 
the  others,  but  the  two  may  be  fused  together,  or  be  closely  opposed. 
In  either  case  they  are  usually  projected  distally  more  or  less,  leading 
backward  into  and  under  the  ramus,  thereby  rendering  extraction  of 
this  tooth  difficult  and  dangerous,  especially  where  the  mandible  is  of 

Fig.  28. 


The  fourth  molar. 


dense  structure  or  where  there  is    impaction.     The  roots    are  usually 

more  rounded,  especially  the  distal  one,  than  those  of  the  other  molars. 

The  pulp  canals  are  generally  divided,  whether  the  root  is  or  not. 


48 


MACROSCOPIC  Ay  A  TO  MY    OF   Till-:   lU'MAX    TEETH. 


As  tlic   nxtts  arc    usually  crooked,   the    dilticiilty  of  onteriiitj:;    them  is 
increased,  as  the  canals  follow  the  form  of  the  roots. 

Fourth  molars  sometimes  a|)|»ear  as  superiiumerarv  teeth,  and  are 
either  fused  to  the  U])]ter  thii'd  molar  in  a  variety  of  uncouth  forms 
(Fi^.  "JS,  (t)  or  eru[)t  sej)arately  as  mere  |)e<;-sliaj)ed  teeth  between  the 
buccal  faces  of  the  second  and  third  molars  (J))  or  at  tlio  distal  aspect 
of  the  latter  t(»oth.  The  fourth  molar  rarely  appears  as  a  full  molar, 
except  in  some  of  the  lar<;e-toothed  races,  as  neg;roes,  Australians,  etc., 
and  then  usually  in  the  lower  jaw.  Among  the  negroes  in  Africa  the 
fourth  molar  is  sometimes  found  in  full  form  as  a  typical  molar. 

Fig.  29. 


Negro  jaw  with  fourth  molar. 


The  Deciduous  Teeth. 

18.  The  DECIDUOUS  teeth  are  those  which  appear  in  infancy  and 
serve  the  purpose  of  dental  organs  during  the  first  years  of  the  develop- 
ment of  the  individual,  until  the  jaws  and  their  environment  are  ready 
for  the  larger,  permanent  teeth  to  come  into  place.  They  bear  a  direct 
relationship  to  the  conditions  of  the  digestive  apparatus  and  the  food 
required  at  that  early  stage.  The  food  of  infancy  being  simple  and 
requiring  little  mastication,  the  deciduous  set  are  small  and  insufficient 
for  the  reduction  of  more  resisting  substances.  As  these  foods  come  to 
form  part  of  the  dietary,  the  larger  teeth  of  the  permanent  set  appear, 
and  perform  the  duties  of  higher  functional  activity. 

The  croicn.s  of  the  deciduous  teeth  resemble,  in  a  general  way,  those 
of  the  permanent  teeth  which  succeed  them,  except  the  deciduous 
molars  (Fig.  30,  a,  d),  which  are  very  different  from  the  bicuspids 
of  the  permanent  set  which  displace  them. 

The  incisors  of  both  jaws  precede  the  analogous  teeth  of  the  same 
series  of  the  ])ermanont  set.  They  are  similar  in  form,  but  reduced  (6), 
and  do  not  have  the  main  features  so  characteristically  marked.  They 
are    infantile   in   form   and   function.       The   roots   of  these    teeth    are 


THE  DECIDUOUS  TEETH. 


49 


resorbed  at  from  the  fifth  to  the  ninth  year,  when  the  permanent  incisors 
come  into  place,  beginning  with  the  lower  centrals. 

The  canines  (c)  of  both  jaws  are  still  more  reduced  from  the  strong, 


Fig.  30. 


The  deciduous  teeth. 


full  form  of  their  permanent  successors,  and  are  but  little  more 
specialized  than  the  incisors.  They  are  of  the  same  general  form  as 
the  permanent  canines,  but  much  less  developed. 

But  in  the  deciduous  molars  are  found  some  important  features 
which  mark  distinctive  differences.  They  are  of  true  molar  form  as 
compared  with  the  permanent  molars,  but  they  occupy  the  place  of  the 
bicuspids.  There  are  no  bicuspids  in  the  deciduous  set,  the  molars  being 
of  full  molar  pattern  {a,  d). 

The  deciduous  molars  of  both  jaws  are  of  irregular,  quadrangular 
form  on  the  morsal  surface,  diverging  rapidly  outward  to  the  neck, 
Avhich  presents  a  large  buccal  ridge  standing  out  at  the  margin  of  the 
enamel,  and  is  rounded  off  suddenly  to  the  neck,  which  is  much  con- 
tracted. This  thick  ridge  is  characteristic  of  the  deciduous  molars  and 
is  absent  in  those  of  the  permanent  denture.  It  is  somewhat  more 
prominent  and  bulging  on  the  buccal  than  on  the  other  faces.  In 
adjusting  ferrule  crowns  to  these  teeth,  the  gold  need  not  be  carried 
beyond  this  ridge  but  burnished  over  it  slightly. 

The  morsal  surface  (e)  of  the  upper  deciduous  grinders  presents  the 
characteristic  pattern  of  the  upper  molars,  four  tubercles,  oblique  ridges, 
etc.,  but  reduced  and  contracted.  A  distinctive  feature  is  that  the 
marginal  ridges  and  angles  are  more  acute  and  sharp  than  in  the  per- 
manent molars.  Sometimes  the  two  lingual  cusps  are  reduced  to  one 
and  the  lingual  border  is  rounded  and  crescentic. 

The  second  molar  is  larger  than  the  first  and  the  morsal  surface  is 
wider. 


50  MACROSCOPIC  AXATO^fy  OF  THE  HUM  AS  TEETH. 

The  transverse  (liaineter  of  the  crowns  of"  the  ujiper  mohirs  is  the 
longest. 

The  i-owKK  MoLxVRs  {d)  are  simihir  to  the  |)ernianent  mohirs  in  pat- 
torn,  hnt  are  more  irrejjnhir  as  to  the  eontonr  of"  the  morsal  surface  (/). 
The  tnherch's  may  he  liiirlier  than  in  the  ii|)|)er  niohirs,  and  the  tri- 
anirnlar  ridijes  more  marked.  The  central  fossa  may  l)e  hir<re  and  wide, 
or  divided  hy  the  trian<j:uhir  rid<res.  The  second  mohir  is  tive-h)i)ed, 
unHke  the  second  permanent  molar,  whicli  has  Imt  four  cusps.  The 
morsal  face  is  decidedly  trajK-zoidal  in  outline,  the  mesio-distal  diameter 
being  greater  than  the  transverse. 

The  roots  of  the  deciduous  molars  are  similar  to  those  of  the  other 
molars,  except  that  they  are  very  divergent  to  accommodate  the  crown 
of  the  advancing  bicuspids.  They  are  thin  and  long,  and  difficult  to 
enter  and  fill.  The  pnlp  chamber  is  large  and  open  in  the  crown  ;  as 
a  consecpienee  of  this  caries  soon  reaches  the  pnlp.  Treatment  and 
filling  of  the  canals  is  difficult  and  uncertain. 

The  Variations  of  Tooth  Forms. 

19.  The  teeth  iiuni  v<try  quite  extensively  from  the  typal  forms  which 
have  been  described,  and  these  variations  may  be  due  to  a  mimber  of 
causes.  Through  all  degrees  of  variation,  however,  the  type  is  still  pre- 
served, unless  the  tooth  form  is  (piite  destroyed  by  pathological  causes. 

The  general  causes  of  variation  may  be  enumerated  as  follows  : 

(1)  Incompleteness  of  development. 

(2)  Reversion  to  primitive  types. 

(3)  Temperamental  impress. 

(4)  Pathological  lesions. 

(1)  Under  incompleteness  of  development  may  be  grouped  all 
those  varieties  of  stunted  growth  which  are  the  effect  of  disuse  and 
the  consequent  effort  of  Nature  to  reduce  and  suppress  the  teeth  as 
useless  parts.  The  third  molar  teeth  suffer  most  from  these  suppressive 
attempts  of  Nature  in  the  effort  toward  economy  of  growth  ;  next  to 
these  teeth,  the  upper  lateral  incisors  are  most  frequently  affected  by 
reduction  of  size,  stunted  growth  and  suppression.  Other  teeth  are 
Rirely  affected,  or  but  very  slightly,  by  this  influence,  except  in  rare 
cases. 

(2)  Under  the  second  head,  reversion  to  primitive  types,  we  have  a 
variety  of  interesting  phenomena  in  the  form  of  parts  of  the  human 
teeth  which  seem  to  be  a  zoological  legacy.  These  consist  of  conspic- 
uous features  which  reappear  and  seem  to  recall  forms  of  the  teeth 
observed  in  some  of  the  lower  animal  orders,  especially  the  quadrumanu 
and  insectivora. 

Among  these  features  may  be  mentioned  the  curved  upper  central 


THE   VARIATIONS  OF  TOOTH  FORMS.  51 

incisor  with  the  prominent  cingule  on  the  lingual -buccal  ridge,  making 
a  notch  which  recalls  the  incisors  of  the  moles  ;  the  prominent  cingule 
on  the  lingual  face  of  the  lateral  incisor,  which  is  not  uncommon  and 
recalls  the  form  found  in  the  insectivora  and  some  of  the  quadrumana ; 
the  extra-long,  curved  canine,  with  extra-large  median  ridges,  which 
recalls  the  large  forms  of  this  tooth  in  the  baboons  and  in  the  car- 
nivora ;  the  double  root  sometimes  found  in  this  tooth  is  also  a  re- 
version to  the  insectivorous  type  ;  the  three-rooted  bicuspid  is  a  quad- 
rumanous  reversion ;  the  upper  tricuspid  molar  is  a  primitive  typal 
form,  leading  back  to  the  lemurs  and  beyond  them  to  the  early  typal 
mammals  found  in  fossil  formations  ;  the  notched  and  grooved  incisor 
recalls  the  divided  incisor  of  the  Galeopithecics  ;  the  double-rooted  lower 
incisors  and  canines  recall  insectivorous  forms ;  the  unicuspid  lower 
first  bicuspid  is  an  insectivorous  type  and  is  often  quite  marked  in  man ; 
the  fifth  cusp  on  the  lower  second  molar  is  a  quadrumanous  rever- 
sion ;  the  wrinkled  surface  of  the  lower  third  molar  is  like  that  of  the 
orang. 

There  are  other  features  that  might  be  named  illustrating  the  work- 
ings of  the  laiv  of  atavism,  by  which  parts  once  lost  in  evolution  may 
reappear  and  be  reproduced. 

(3)  Under  the  third  head,  temperamental  impress,  may  be  noticed 
those  differences  of  form  and  structure  which  have  relation  to  the  domi- 
nant temperament  in  the  constitution  of  the  individual.  Great  differ- 
ences exist  between  the  teeth  of  different  persons,  and  these  are  mainly 
dictated  by  temperament. 

The  teeth  of  the  primary  basal  temperaments  present  the  following 
physical  peculiarities,  which  are  characteristic  of  the  particular  tempera- 
ment : 

The  BILIOUS  TEMPEEAMENT  presents  teeth  that  are  of  a  strong 
yellow ;  large,  long,  and  angular,  often  with  transverse  lines  of  forma- 
tion, without  brilliancy,  transparency,  and  of  but  slight  translucency ; 
firm  and  close  set  and  well  locked  in  articulation. 

The  SAXGUINE  TEMPERAMENT  has  teeth  that  are  symmetrical  and 
well  proportioned,  with  curved  or  rounded  outlines,  and  round  cusps  ; 
cream  color,  inclined  to  yellow,  rather  brilliant  and  translucent ;  well 
set,  and  occlusion  firm. 

The  NERVOUS  TEMPERAMENT  has  teeth  which  are  rather  long,  the 
cutting  edges  and  cusps  long  and  fine ;  color  pearl-blue  or  gray,  very 
transparent  at  the  apex  ;  the  occlusion  very  penetrating. 

The  LYMPHATIC  TEMPERAMENT  presents  teeth  that  are  pallid  or 
opaque,  dull  or  muddy  in  coloring ;  large,  broad,  ill-shaped,  cusps  low 
and  rounded  ;  the  occlusion  lose  and  flat. 

Of  the  binary  combinations: 


52  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

The  sANcriNKo-iiiLiors  has  teeth  which  are  hirjije,  with  strong  edges 
and  hirge  eiisps  ;  color  dark  yellow,  and  quality  good. 

The  Nf:RVO-Rn.i()rs  has  teeth  that  are  long  and  narrow,  with  long 
cusps  ;  color  yellowish  or  bluish  or  both  combined  ;  the  enamel  strong, 
the  dentin  soft. 

The  i.YMPHO-Bii.iOT^s  has  teeth  that  are  large,  with  thick  edges  and 
short  thick  cusps  ;  yellowish  in  color  ;  enamel  of  good  structure  and 
polish,  and  dentin  fair. 

The  BiLi<)-sAN(a'iNEOUS  has  teeth  of  average  size,  round  arch,  well- 
developed  cusps  and  edges  ;  rich  dark-cream  color ;  excellent  in  quality. 

The  NERVO-SANGUINEOUS  has  teeth  of  average  size,  good  shape,  round 
arch,  good  edges  and  cusps  ;  rich  cream  (?olor ;  enamel  and  dentin  of 
excellent  structure. 

The  I.YMPHO-SANGUINEOUS  has  teeth  of  more  than  average  size, 
shapely  edges  and  cusps,  rounded  arch  ;  color  grayish  cream  ;  enamel 
and  dentin  fairly  good. 

The  Bii.io-NERVOus  has  teeth  variable  in  size  and  form,  sometimes 
broad,  again  very  long  with  more  pointed  and  long  cusps ;  the  color 
generally  bluish  ;  enamel  fairly  good,  dentin  soft  and  sensitive. 

The  sANGUiNEo-NERVors  has  teeth  of  average  size,  good  shape, 
round  arch  ;  color  grayish  blue  ;  soft  and  frail. 

The  Biivio-LYMPHATic  luis  teeth  usually  large,  with  thick  edges, 
short  thick  cusps,  and  flat  arch  ;  color  yellowish  ;  quality  good. 

The  SANGUiNEO-LYMPHATic  has  teeth  of  more  than  the  average  size, 
broad  round  arch  ;  color  gray  ;  enamel  and  dentin  poor. 

The  np:rv()-ia'MPHATIC  has  teeth  of  average  size,  good  shape,  aver- 
age length,  rather  round  arch  ;  color  bluish  gray  ;  soft  and  poor. 

Combinations  of  the  binaiy  temperaments  are  of  the  most  common 
occurrence  in  individuals,  but  there  is  usually  one  basal  temperament 
that  preponderates  over  the  others  and  gives  its  characteristic  to  the 
teeth  as  a  predominating  influence. 

(4)  Under  the  fourth  head,  pathological  lesions,  are  to  be  included 
all  those  disturbances  of  nutrition  which  eventuate  in  faidty  formation 
of  the  teeth,  whether  due  to  specific  hereditary  diseases,  mere  malnutri- 
tion, idiosyncrasies,  predispositions,  defective  fimctional  life,  etc.  But 
this  leads  beyond  the  province  of  this  chapter  into  the  field  of  special 
pathology. 


CHAPTER   IT. 

DENTAL  HISTOLOGY  WITH  REFERENCE  TO  OPERATIVE 

DENTISTRY.^ 

By  Frederick  B.  Noyes,  B.  A.,  D.  D.  S. 


The  development  of  our  knowledge  of  the  cell  has  had  a  most  pro- 
found effect  upon  the  entire  practice  of  medicine  ;  in  fact,  the  progress  of 
modern  medicine  dates  from  the  studies  of  cell  biology,  the  germ  theory  of 
disease  being  only  one  of  the  phases  of  this  development.  In  terms  of  the 
cell  theory  the  functions  of  the  body  are  but  the  manifest  expression  of 
the  activities  of  thousands  or  millions  of  more  or  less  independent  but 
correlated  centres  of  activity :  if  these  centres  or  cells  perform  their 
functions  correctly,  the  functions  of  the  body  are  normal ;  but  if  they 
fail  to  perform  their  office,  or  work  abnormally,  the  functions  of  the 
body  are  perverted.  In  the  last  analysis,  then,  all  physiology  is  cell 
physiology ;  all  pathology  cell  pathology.  To  modern  medicine  his- 
tology, or  the  cell  structure  of  the  organs  and  tissues  of  the  body, 
together  with  cell  physiology,  is  the  rational  foundation  of  all  practice. 
This  is  as  true  for  the  dentist  as  for  the  piij^sician  so  far  as  regards  all 
of  the  soft  tissues  of  the  mouth  and  teeth  that  he  is  called  upon  to 
treat  and  handle.  With  caries  of  the  teeth,  the  disease  which  most 
demands  the  attention  of  the  dentist,  the  case  is  somewhat  different. 
Caries  of  the  teeth  is  an  active  destruction,  by  outside  agencies,  of 
formed  materials  which  are  the  result  of  cell  activity  (the  tissues  them- 
selves being  passive).  The  cellular  activities  of  organs  and  tissues  of 
the  body  may  have  an  influence,  but  this  is  only  in  producing  those 
conditions  of  environment  which  render  the  activities  of  the  destructive 
agents  efficient  in  their  action  upon  tooth  tissues.  Though  the  enamel 
and  dentin  are  passive,  we  can  understand  the  phenomena  of  caries 
only  as  we  understand  the  structure  of  the  tissues ;  and  not  only 
must  the  treatment  of  caries  be  based  upon  a  knowledge  of  the 
structure  of  the  tissues,  but  the  mechanical  execution  of  the  treatment 
is  facilitated  by  that  knowledge.  In  the  preparation  of  cavities  the 
arrangement  of  the  enamel  wall  is  determined  by  our  knowledge  of 
the  direction  of  enamel  prisms  in  that  locality,  and  to  a  certain  extent 

^  In  the  preparation  of  this  material  I  am  indebted  to  Dr.  G.  V.  Black  for  the  use  of 
his  large  and  valuable  collection  of  microscopic  slides,  and  for  much  advice  and  many 
suggestions. 

53 


54 


DhW'J'AL    mSTOlJX.y  ASI>   OPERATIVE  DEyiTISTRY. 


tlir  position  of  tlu:  cavity  inar<;iiis  must  he  governed  hy  our  knowledge 
ot'  tlie  structure  of  the  enamel.  In  the  execution  of  the  work  a  niiiuite 
knowledge  of  the  direction  of  enamel  rods  becomes  the  most  important 
element    in   ra[)idity  and  success  of  operation. 

From  the  standpoint  of  comparative  anatomy,  the  teeth  are  found 
to  l)e  not  a  part  <tf  the  osseous  svstem,  hut  appendages  of  the  skin, 
and  are  to  i)e  compared  with  such  structures  in  tlie  body  as  the  nails 
and  the  hair.  The  teeth  are  a  part  of  the  exo-skeleton,  and  their  rela- 
tion to  the  l)ones  of  the  endo-skeleton  is  entirely  secondary,  for  the  })ur- 
j)ose  of  strength,  tlie  Ixtne  growing  uj)  around  the  tooth  to  support  it. 

If  we  examine  the  skin  of  such  an  animal  as  the  shark,  we  Hud 
the  entire  surface  covered  with  small   calcified   bodies  which  are  reallv 


Fk. 

M. 

1 

i 

^^>y>j^^^H^^H 

1  ^ 

J 

^^^V 

Shark's  skull  (Lainua  cornubica),  showing  succession  of  teeth. 

small  simple  cone-shaped  teeth.  The  mouth  cavity  is  to  be  regarded, 
when  viewed  in  the  light  of  its  development,  as  a  part  of  the  outside 
surface  of  the  body  which  has  been  inclosed  by  the  development  of  the 
neighboring  parts,  and  the  dermal  scales  or  rudimentary  teeth  which 
were  found  in  the  skin  covering  the  arches  which  form  the  jaws  have 
undergone  special  development  for  the  purposes  of  seizing  and  masti- 
cating the  food.  In  the  simplest  forms  there  is  only  a  development 
in  size  and  shape  of  these  scales,  and  they  are  supported  only  by  the 
connective  tissue  which  underlies  the  skin.  These  teeth  are  easily  torn 
off  in  the  attempt  to  hold  a  resisting  prey,  and,  as  in  the  shark,  they  are 
constantly  being  replaced  by  new  ones  (Fig.  31).  In  the  more  highly  de- 
veloped forms  there  is  a  growth  of  the  bone  of  the  arch  forming  the  jaw 


DENTAL   TISSUES.  ^^ 

upward  around  the  bases  of  these  scale-like  teeth,  to  support  them 
more  firmly  and  render  them  more  useful. 

If  we  compare  the  structure  of  the  hair  with  that  of  the  tooth,  we 
find  in  the  case  of  the  hair  a  horny  structure  formed  by  epithelial 
cells  resting  upon  a  papilla  of  connective  tissue;  in  the  case  of  the 
tooth,  a  calcified  structure  formed  by  epithelial  cells  resting  upon  a 
papilla  of  connective  tissue  which  is  also  partially  calcified. 

The  relation  of  the  bones  of  the  jaws  to  the  teeth  is  entirely  a  secondary 
and  transient  one.     The  bone  grows  up  around  the  roots  of  the  teeth  to 

Fig.  32. 


Changes  in  the  mandible  with  age  ;  buccal  and  lingual  view. 

support  them,  and  is  destroyed  and  removed  with  the  loss  of  the  teeth 
or  the  cessation  of  their  function.  In  this  way  the  development  of  the 
alveolar  process  takes  place  around  the  temporary  teeth  ;  all  of  this  bone 
surrounding  their  roots  is  absorbed  and  removed  with  the  loss  of  the 
temporary  dentition,  and  a  new  alveolar  process  grows  up  around  the 
roots  of  the  permanent  teeth  as  they  are  formed.  This  development  of 
bone  around  the  roots  of  the  teeth  leads  to  the  changes  in  the  shape  of 
the  body  of  the  lower  jaw,  increasing  the  thickness  above  the  mental 
foramen  and  the  inferior  dental  canal.  When  the  teeth  are  finally  lost 
this  bone  is  again  removed  and  the  body  of  the  jaw  is  reduced  in  thick- 
ness from  above  downward  (Fig.  32).  These  phenomena  are  of  im- 
portance in  their  bearing  upon  the  causes  and  treatment  of  diseased  con- 


66  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

ditions   of  the  teeth,  particularly  those  which  involve  the  supporting 
tissues. 

Dental  Tissues. — The  human  teeth  are  made  up  of  four  tissues 
(Fi^^.  33) : 

1 .  The  enamel  covers  the  exposed  portion  of  the  tooth,  or  crown, 
and  gives  the  detail  of  crown  form.  Its  function  is  to  protect  the  tooth 
against  the  wear  of  friction. 

2.  The  dentin  forms  the  mass  of  the  tooth  and  determines  its  class 
form,  the  number  <»f  cusps  and  the  innnber  of  roots  being  indicated  by 
the  dentin  form. 

3.  Cementum  covers  the  dentin  beyond  the  border  of  the  enamel, 
overlapping  it  slightly  at  the  gingival  line  and  forming  the  surface  of 
the  root.  Its  function  is  to  furnish  the  attachment  of  the  fibers  of  the 
peridental  membrane,  which  fastens  the  tooth  to  the  bone. 

4.  The  pulp  or  soft  tissue  filling  the  central  cavity  in  the  dentin 
is  the  remains  of  the  formative  organ  which  has  given  rise  to  the  dentin. 
Its  functions  are  the  formation  of  dentin  and  a  sensory  function. 

In  describing  the  structure  of  the  teeth  and  the  arrangement  of  the 
structural  elements  of  the  tissues  directions  are  described  with  reference 
to  three  planes  : 

The  mesio-disto-axial  plane,  a  plane  passing  through  the  centre  of  the 
crown  from  mesial  to  distal  and  ])arallel  with  the  long  axis  of  the  tooth. 

The  bucco-linguo-axial  plane,  a  plane  passing  through  the  centre  of 
the  crown  from  buccal  to  lingual  and  parallel  with  the  long  axis  of  the 
tooth. 

The  horizontal  plane,  at  right  angles  to  the  axial  planes. 

The  Supporting-  Tissues. — The  human  teeth  are  supported  on  the 
maxillary  bones,  their  alveolar  processes  growing  up  around  the  roots  of 
the  teeth,  so  that  the  roots  fit  into  the  holes  in  the  bone.  The  calcified 
structures  of  the  tooth  and  the  bone  are  not,  however,  united,  but  the 
roots  are  surroiuided  by  a  fibrous  membrane,  the  pendenlal  membra'ne^ 
or  peincementinn,  which  fastens  the  tooth  to  the  bone. 

Enamel. 

The  enamel  differs  from  all  other  calcified  tissues  in  the  nature  of 
the  structural  elements  of  which  this  tissue  is  made  up,  in  the  degree 
of  calcification,  and  in  origin,  being  the  only  calcified  tissue  derived 
from  the  epiblast. 

The  enamel  is  formed  from  an  epithelial  organ  derived  from  the 
epithelium  of  the  mouth  cavity  and  indirectly  from  the  epiblastic  germ 
layer,  while  all  other  calcified  tissues  are  products  of  the  niesoblast. 
In  the  case  of  bone  and  dentin  the  formative  tissue  is  persistent.     It 


ENAMEL. 

Fi(i.  33. 


57 


Ground  section  of  a  canine  :  E,  enamel ;  Cm,  cementum  ;  I),  dentin  ;  Pc,  pulp  chamber  ;  De,  dento- 
enamel  junction  ;  £rf,  enamel  defect ;  G',  junction  of  enamel  and  cementum  at  the  gingival  line; 
6t,  granular  layer  of  Tomes.    (Reduced  front  photomicrograph  made  in  three  sections.) 


58  DENTAL  HISTOLOCY   AMt    tn'EllATIVK  DENTISTRY. 

is  possible  ill  the  boiic  at  least,  tlwretorc,  to  have  (h'jreiierative  and  re- 
generative changes,  or  the  removal  of  part  of  the  ealciuni  salts  and  their 
rephieeinent  tlirougli  tlie  aireiiey  of  the  formative  tissue  ;  while  in  the 
enamel  no  sucii  regenerative  change  is  possible,  as  the  formative  tissue 
disappeared  when  the  tissue  was  completed  and  before  the  eruption  of 
the   tooth. 

The  enamel  is  the  hardest  of  human  tissues.  Chemieallv  it  is  com- 
posed of  the  phosphates  and  carbonates  of  calcium  and  magnesium  and 
a  very  small  amount  of  the  fluorids,  water,  also  a  very  small  amount 
of  organic  matter  if  any.'  The  enamel  in  the  natural  condition,  bathed 
in  the  fluids  of  the  mouth,  contains  a  considerable  amount  of  water. 
If  dried  at  a  little  above  the  boiling-point  of  water,  it  gives  up  part 
of  it  and  shrinks  considerably,  so  as  to  crack  in  fine  cheeks.  If  heated 
almost  to  redness,  it  suddenly  gives  off'  from  ."3  to  o  per  cent,  (of  the 
dry  weight)  of  water  with  almost  explosive  violence.  These  facts  were 
demonstrated  some  years  ago  by  Charles  Tomes,"  and  account  for  nu)st 
of  what  was  formerly  recorded  as  organic  matter  in  old  analyses. 

If  we  observe  under  the  microscope  the  action  of  acids  upon  thin 
sections  of  enamel,  when  the  inorganic  salts  are  entirely  removed,  the 
structure  of  the  tissue  vanishes,  there  being  no  trace  of  organic  matrix 
left  as  in  the  case  of  bone  or  dentin.  In  the  growth  of  bone  and 
dentin  the  formative  tissue  produces  first  an  organic  matrix  in  the  form 
of  the  tissue,  and  into  this  the  inorganic  salts  are  dej)osited,  combining 
with  the  organic  substances  of  the  matrix.  This  union  is  comj)ara- 
tively  weak,  however,  for  by  the  action  of  acids  the  combination  is 
broken  up  and  the  inorganic  salts  arc  dissf>lved  ;  or  by  heat  the  organic 
matter  is  removed,  and  in  either  case  the  form  of  the  tissue  will  be 
maintained. 

In  the  case  of  the  enamel,  the  formative  organ  produces  organic 
substances  containing  inorganic  salts,  and  the  substances  are  arranged 
in  the  form  of  the  tissue  after  the  manner  of  a  matrix;  but  finally 
imder  the  action  of  the  formative  organ  all  of  the  organic  matter  is 
removed  and  substituted  by  inorganic  salts,  whatever  organic  matter  is 

'  Von  Bibra  gives  the  following  analysis  of  enamel : 

(  alcinm  phosphate  and  fliiorid 89.82 

Calcium  carbonate 4.37 

Magnesium  phosphate 1.34 

Other  salts 88 

Cartilage 3.39 

Fat 20 

Total  organic 3.59 

"      inorganic 96.41 

*  Journal  of  Physiology,  1896.  ^ 


ENAMEL. 


59 


found  in  the  fully  formed  tissue  being  the  result  of  imperfect  execution 
of  the  plan. 

The  enamel  is  composed  of  two  structural  elements,  the  enamel,  rods, 
or  prisms,  sometimes  called  enamel  fibers,  and  the  interprismatic  or 
CEMENTING  SUBSTANCE,  both  of  which  are  calcified.  It  is  to  the  arrange- 
ment of  these  structural  elements  that  the  characteristics  of  the  tissue 
with  which  we  are  most  concerned  in  operative  procedures  are  due. 

While  both  the  prisms  and  interprismatic  substance  of  the  enamel 
are  calcified,  or,  better,  composed  of  inorganic  salts,  the  two  substances 
— that  is,  the  substance  of  the  rods  and  the  substance  between  the  rods 
— show  markedly  different  properties  both  chemical  and  physical.  If 
treated  with  acid,  the  interprismatic  substance  is  acted  upon  more 
rapidly  than  the  rods,  so  that  the  latter  become  more  conspicuous.  By 
this  means  sections  of  the  enamel  may  be  etched  to  render  it  easier  to 
study  the  direction  and  arrangement  of  the  rods.  If  the  action  of  the 
acid  is  carried  far  enough,  the  rods  will  fall  apart  before  they  are  them- 

FiG.  34. 


Enamel  rods  isolated  by  caries.    (About  465  X.) 

selves  entirely  dissolved.  Fig.  34  is  from  the  debris  in  a  carious  cavity, 
and  shows  rods  isolated  by  the  action  of  the  acids  of  caries. 

The  interprismatic  substance  is  not  as  strong  as  the  rods,  so  that  in 
splitting  or  breaking  the  enamel  the  tissue  separates  on  the  lines  of  the 
cementing  substance,  occasionally  breaking  across  a  few  rods  but  fol- 
lowing their  general  direction,  the  lines  running  between  rods,  not  at 
their  centres. 

In  cleaving  the  enamel  the  chisel  does  not  enter  the  tissue  sepa- 
rating rod  from  rod,  but  the  edge  engages  with  the  surface,  and   the 


60  liKSTAl.    insTolJxiY    AM)    OPERATIVE   DEyTlSTRY. 

force  applied  at  an  acute  angle  with  the  <lincti<»n  of"  the  rods  fractures 
the  tissue  in  the  lines  of  least  resistance.  If  the  edge  be  keenly 
sharp,  it  will  enter  the  tissue  slightly,  and  then  the  bevel  acts  as  a 
wedge  in  addition  to  the  force  applied  to  the  shaft  of  the  instrument; 
but  if  the  edge  be  dull,  it  will  rest  across  the  ends  of  many  rods,  will 
not  engage  with  the  surface,  and  the  force  applied  will  break  and 
crumble  the  tissue  but  will   not  cleave  it. 

The  enamel  rods,  or  prisms,  aiv  long,  slender  prismatic  rods  or 
fibers,  five-  or  six-sided,  j)ointed  at  both  ends  and  alternately  ex])anded 
and  constrict(>d  throughout  their  length.  They  are  from  8.4  to  4.5 
microns'  in  diameter,  some  of  them  apparently  reaching  the  entire 
distance  from  the  surface  of  the  dentin  to  the  surface  of  the  enaiuel  ; 
but  as  the  diameter  of  the  rods  is  the  same  at  their  outer  and  inner 
ends,  and  as  the  crown  surface  is  much  greater  than  the  surface  of  den- 
tin covered  by  enamel,  there  are  many  rods  which  do  not  extend 
through  the  entire  thickness.  These  short  rods  end  in  tapering  points 
between  the  converging  rods  which  extend  the  entire  distance.  To 
express  this  in  terms  of  development :  as  the  formation  of  enamel 
begins  at  the  surface  of  the  dentin,  the  increasing  area  of  crown  sur- 
face requires  more  ameloblasts,  and  as  new  ameloblasts  take  their  place 
in  the  layer  the  formation  of  new  enamel  rods  begins  between  the  rods 
which  were  jireviously  forming.  These  short  rods  are  most  numerous 
over  the  marginal  ridges  and  at  the  points  of  the  cusps,  and  will  be 
considered  more  fully  in  connection  with  those  positions. 

In  ground  sections  cut  at  right  angles  to  the  direction  of  the  rods'' 
the  tissue  has  the  appearance  of  a  mosaic  floor,  the  outline  of  the  rods 
being  more  distinct  if  they  have  been  marked  out  by  treating  the  section 
.slightly  with  acid  (Fig.  35).  In  longitudinal  sections  (Fig.  36)  the  si(h's 
of  the  rods  are  not  smooth  and  even  like  the  sides  of  a  lead  pencil,  but 
are  alternately  expanded  and  constricted.  They  are  well  illustrated  by 
taking  balls  of  soft  clay  and  sticking  them  together  one  above  another 
to  form  a  rod,  then  ])utting  a  nimiber  of  rods  together  so  that  by 
mutual  pressure  they  take  hexagonal  forms.  This  illustrates  also  the 
manner  of  growth  of  the  tissue  in  formation.  The  expansions  and 
constrictions  can  be  seen  in  rods  that  have  been  scraped  from  a  cleaved 
surface  of  enamel,  but  better  by  isolating  rods  by  the  slight  action  of 
dilute  acid  (Fig.  37). 

In  the  construction  of  the  tissue  the  rods  are  so  arranged  that  the  ex- 

'  A  micron  is  tlie  unit  of  microscopic  mensiiremont.  and  is  ecpial  to  f.ne  one-tlionsandtli 
of  a  millimeter. 

•^  In  describing  the  direction  of  enamel  rods  tliey  are  always  considered  as  extending 
from  the  dentin  to  tlie  sinface,  and  the  angle  is  formed  at  I  he  sni-face  of  the  dentin  with 
the  locating  plane,  either  horizontal  or  a.\ial. 


ENAMEL. 


61 


pansions  of  one  rod  come  opposite  to  the  expansions  in  the  adjoining 
rods,  and  do  not  interlock  with  their  constrictions.     This  arrangement 


Fig.  35. 


Transverse  seetiun  of  enamel  rods.     (About  so     .) 

leaves  alternately  a  greater  and  a  less  amount  of  cementing  substance 
between  them. 

Fly.  36. 


Enamel  rods  in  thin  etched  section.    (About  800 X.) 

When  observed  under  the  microscope,  the  enamel  rods  show  a  char- 
acteristic appearance  of  light  and  dark  lines  running  across  them. 
These  markings  are  similar  to  the  striations  of  voluntary  muscle  fibers, 


<>2 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


and  are  described  as  the  striation  of  the  fiuuncl.      It  is  seen  not  only  in 
isolated  rods  (Fig.  34),  but  also  in  sections  ground  in  their  direction  (Fig. 


Fi...  :{7. 


Enamel  rods  isolated  by  scraping.    (About  SUO  a  .) 

38).     This  appearanw  of"  striation  in  the  enamel  is  caused  by  the  alter- 
nate expansions  and  constrictions  of  the  rods  refracting  the  light  like  a 

Fu;.  .'is. 


Enamel  showing  striation.     (About  IfniO  v.) 


lens.  In  sections  the  expansions  in  adjoining  rods  are  opposite  to  each 
other,  the  difference  in  the  refracting  power  of  the  prismatic  and  inter- 
prismatic  substances  producing  the  same  effect. 


ENAMEL.  63 

The  appearance  of  striation  is  the  record  in  the  fully  formed  tissue 
of  the  manner  of  growth,  each  dark  stripe,  or  expansion,  in  a  rod 
representing  a  globule  of  partially  calcified  material.  The  ameloblasts 
build  up  the  rods  by  the  addition  of  globule  after  globule,  surrounding 
them  with  a  cementing  substance  and  completing  the  calcification  of 
both.  In  this  sense  the  striation  of  the  enamel  may  be  said  to  record 
the  growth  of  the  individual  rods. 

While  the  enamel  is  a  very  hard  substance  when  its  structure  isi 
complete  and  perfect,  its  most  striking  physical  characteristic  is  a  ten- 
dency to  split  or  crack  in  the  direction  of  its  structural  elements  when 
a  break  has  been  made  in  the  tissue.  While  it  is  difficult  to  cut  across 
the  rods  or  make  an  opening  on  a  perfect  surface,  if  a  break  has  been 


Fig.  39. 

Sli    , 

• 

,t-  rm^^^^t 

>i    ..-ja^.y|HJ 

M 

1' 

■  1. 

1 

\.  i '       "^^H 

m 

\\ 

J 

^^H^ 

.■''i?.'f '^  t,  j 

lliltlllllMillll  'll'l'li*ll 

l^^^gg 

J 

Enamel  showing  direction  of  cleavage.    (About  70  X.) 

established  it  is  comparatively  easy  to  split  off  the  tissue  from  the  sides 
of  the  opening  when  the  rods  lie  parallel  with  each  other.  Fig.  39 
shows  a  field  of  enamel  illustrating  the  way  in  which  the  tissue  splits 
or  cleaves  in  the  direction  of  the  rods. 

Upon  the  axial  surfaces  the  enamel  rods  are  usually  straight  and 
parallel  with  each  other,  except  where  there  has  been  some  flaw  or 
disturbance  in  development ;  but  upon  the  occlusal  surface,  although 
sometimes  straight,  they  are  very  often  much  twisted  and  wound 
round  each  other,  especially  at  their  inner  ends.  This  difference  in  the 
arrangement  of  the  rods  causes  the  greatest  difference  in  the  feeling 
of  the  tissue  under  cutting  instruments.  Such  a  specimen  of  enamel  as 
shown  in  Fig.  40  can  be  cut  away  easily,  the  tissue  breaking  through 
to  the  dentin  and  splitting  off  in  chunks ;  while  a  specimen  like  Figs. 
41  and  42  will  not  cleave  if  supported  upon  sound  dentin.     If  the  outer 


64  DENTAL  HISTOLOGY  AXP    OPERATIVE  DENTISTRY. 

I'ui.  40. 


Strai;;lil  eiiaiiu-1  rods,     i  Alxnit  8fi:-;.) 
Fu;.  41. 


Gnarled  enamel.     (About  .'OX.) 


ENAMEL. 


65 


ends  of  the  rods  are  straight,  they  will  split  part  way  to  the  dentin  (Fig. 
42)  ;  but  where  they  begin  to  twist  round  each  other  they  will  break 
across  the  rods.  If  the  dentin  is  removed  from  under  such  enamel,  it 
will  break  in  an  irregular  way  through  the  gnarled  portion. 

From  a  study  of  the  arrangement  of  the  enamel  rods  in  the  forma- 
tion of  the  crown  it  is  apparent  that  the  plan  is   such  as  to  give  the 

Fig.  42. 


Gnarled  enamel.    (About  50  X.) 


greatest  strength  to  the  perfect  structure,  and  may  be  likened  to  an  arch. 
At  the  gingival  border  the  rods  are  short  and  are  inclined  apieally  6  to  10 
centigrades  ^  (20°  to  35°)  from  the  horizontal  plane.     These  short  rods 


^  In  the  Centigrade  division  the  circle 
is  divided  into  one  hundred  parts,  each 
called  a  centigrade.  One  centigrade  is 
equal  to  3.6  degrees  of  the  astronon)ical 
circle,  25  centigrades  to  90  degrees,  12^ 
centigrades  to  45  degrees.  The  cut  gives 
a  comparison  of  the  two  systems  of  meas- 
uring angles. 


270 


180 

Centigrade  division. 


66 


DENTAL  HISTOLOGY  AM)   OPERATIVE  DENTISTRY' 


arc  overlapped  for  a  short  distance  l)y  the  ceiiicntiim.  This  inclination 
grows  less  and  less,  and  at  some  |)laet'  in  the  uinuival  halt"  of  the  middle 
third  of  the  snrface  they  are  in  the  horizontal  i)lane.  At  this  jioint  they 
are  also  nsnally  perpendicular  to  the  surface  ot'  the  dentin.  Passing 
from  this  j»oint  they  become  inclined  more  and  more  occlnsallv  from  the 
horizontal  plane,  at  the  Junction  of  the  occlusal  and  middle  thirds  about  8 
to  12  centigrades  (28°  to  40°)  in  bicuspids  and  molars,  and  8  to  18 
centigrades  (28°  to  65°)  in  incisors  and  canines.  In  the  occlusal  third 
the  inclination   increases  raj)idly,  and  often  the  outer  ends  of  the  rods 

Fig.  43. 


Iiin<?ram  of  enamel  rod  directions,  from  a  photograph  of  a  bucco-lingual  section  of  an  upper 

bicuspid. 


are  inclined  more  than  the  inner  ends.  Over  the  point  of  the  cusps 
and  the  crest  of  the  marginal  ridges  the  rods  reach  the  axial  plane, 
though  they  are  often  very  much  twisted  about  each  other  in  the  inner 
half  of  their  length.  This  position  does  not  always  correspond  with  the 
highest  point  of  the  cusp,  but  is  inclined  slightly  axially  from  that  posi- 
tion, and  corresponds  with  the  highest  point  of  the  dentin  cusp. 

Passing  down  the  central  slope  of  the  cusp,  or  ridge,  the  rods 
become  again  inclined  aw^ay  from  the  axial  plane  toward  the  groove,  or 
]iit,  leaning  toward  each  other  where  the  two  plates  meet.  The  degree  of 
inclination  of  the  rods  on  the  central  slope  of  the  cusps  depends  upon  the 


ENAMEL. 


67 


height  of  the  cusps ;  the  higher  the  cusp  the  greater  the  inclination  from 
the  axial  plane.  Fig.  43,  a  diagram  from  a  photograph  of  a  bucco- 
lingual  section  of  an  upper  bicuspid,  shows  the  plan  of  arrangement  and 
illustrates  the  arch  principle  in  the  construction. 


Fig.  44. 


stratification  of  enamel ;  the  cusp  of  a  bicuspid  :  De,  dento-enamel  junction  ;  Ed,  enamel  defect 
showing  in  the  heavy  stratification  band  ;  Ig,  interglobular  spaces  in  the  dentin.  (About 
40  X.) 


In  the  study  of  longitudinal  sections  of  the  teeth,  one  of  the  most 
conspicuous  structural  features  is  the  stratification  bands,  or  brown 
bands  of  Retzius.  These  bands  are  not  parallel  with  either  the  outer 
surface  of  the  enamel  or  the  dento-enamel  junction.  They  begin  at  the 
tip  of  the  dentin  cusps  and  sweep  around  in  larger  and  larger  zones. 
These  stratification  bands  are  better  seen  in  comparatively  thick  sec- 
tions, and  are  caused  by  the  varying  amount  of  pigment  deposited  with 


(iS 


DhWTAL    HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


the  calcium  salts  in  tlic  (Icvclopiiu'ul  of  llic  tissue.  Tiiev  record  the 
growth  of  onanu'l  of  the  crown  as  a  whole,  as  each  line  was  at  one  time 
the  surface  of  the  enamel  cap.  These  stratilications,  or,  better,  incre- 
mental lines,  are  shown  in  V'v^>.  44-4G. 

At  the  time  the  rod  at  .1  (  Fiir.  4"))  was  completely  i'onned   the  rod  at 
B  was  just  beginning  to  form  at   its  dentinal  end.     From   this  it  Mould 


li(..    15. 


Incisor  tip  showing  stratiliratinu  cr  incremental  lines.     Rods  at  .1  were  fully  forined  at  the  time 
the  rods  at  B  were  beginning  to  form.    (.Vbout  50  X.) 


seem  that  any  structural  defect  due  to  imperfect  development  would  not 
follow  the  direction  of  the  enamel  rods  from  the  surface  to  the  dentin, 
but  would  follow  the  stratification  lines ;  and  if  these  structural  defects 
influenced  the  penetration  of  caries,  we  should  expect  to  have  the  direc- 
tion of  penetration  modified.  Fig.  44  shows  a  structural  defect  in  the 
enamel  over  a  cusp  following  the  stratification  band,  and  it  will  be 
noticed  also  that  there  is  a  structural  defect  in  the  dentin  at  a  corre- 
sponding position. 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS. 


69 


HISTOLOGICAL     REQUIREMENTS     FOR    STRENGTH     IN     ENAMEL 

WALLS. 

1.  The  enamel  must  be  supported  upon  sound  dentin. 

2.  The  rods  which  form  the  cavo-surface  angle  must  run  uninter- 
ruptedly to  the  dentin  and  be  supported  by  short  rods,  with  their  inner 
ends  resting  on  the  dentin  and  their  outer  ends  abutting  upon  the  cavity 
wall,  where  they  will  be  covered  in  by  the  filling  material. 

3.  That  the  cavo-surface  angle  be  cut  in  such  a  way  as  not  to  expose 
the  ends  of  the  rods  to  fracture  in  condensing  the  filling  material  against 
them. 

The  first  step,  then,  in  the  preparation  of  an  enamel  wall  is  to  deter- 
mine the  direction  of  the  enamel  rods  by  cleavage  with  a  chisel  or  hatchet. 

Fia.  4B. 


Enamel  show 


triation  and  stratification,     i  Aii^ut  sO,-'.) 


In  Figs.  47  and  48,  No.  1  shows  an  enamel  wall  after  cleaving  the  enamel 
with  a  hatchet.  It  will  be  noticed  that  the  split  has  not  followed  the 
direction  of  the  rods  exactly,  but  has  broken  across  them,  slivering  the 
rods  as  wood  slivers  in  splitting.  This  would  cause  in  the  cut  surface 
a  whitish,  opaque  appearance.  The  plane  of  the  enamel  wall  should  be 
extended  so  as  to  form  a  small  angle  with  the  plane  of  the  dentin  wall, 
by  shaving  the  surface  with  a  very  sharp  hand  instrument.  No.  2  shows 
the  same  wall  after  it  has  been  extended  somewhat ;  but  it  will  be  seen 
that  it  has  not  been  extended  enough,  for  the  rods  forming  the  sur- 
face at  A  do  not  reach  the  dentin,  but  run  out  at  B  on  the  cavity  '/all, 
and  that  piece  would  chip  out  in  packing  against  it  or  if  force  came  upon 
the  surface  afterward.     The  angle  should  be  extended  so  as  to  produce 


70 


DENTAL   HISTOLOGY  AM)   OPERATIVE  DENTISTRY 


o  — 
C    tr. 

c  V 


«5Q 


HISTOLOGICAL  BEQUIBEMENTS  IN  ENAMEL    WALLS. 


71 


Preparatioa  of  enamel  wall  in  gnarled  enamel:  1.  Enamel  wall  as  cleaved,  showing  breaking 

across  rods  and  slivering  at  a.  2.  Wall  as  smoothed  but  not  extended  to  remove  short  rods 
whose  inner  ends  are  cut  off  at  b.  6.  Wall  extended  and  trimmed  to  a  position  of  strength. 
D,  dentin ;  De,  dento-enamel  junction  ;  c,  cavosurface  angle ;  b,  point  where  inner  ends  of 
rods  are  cut  off;  a,  slivering  of  the  tissue.    (About  -SO  K-) 


72  DF.\r.\L    IIISTOLOOY  AND    OPERATIVE  DENTISTRY. 

the  plaiu'  shown  in  NO.  "?>  ;   then  the  eavo-surlaee  angle  may  or  may  not 
1)1'  Ix'velled  as  the  position  demands. 

In  some  positions,  as  on  the  axial  snrfaces,  it  is  not  possible  to  ex- 
tend the  phme  of  the  entire  enamel  wall  as  described  ;  all  that  can  be 
doni'  is  to  shave  the  cut  surface,  leaving  the  wall  in  the  direction  of  the 
enanicl  rods,  and  then  the  margin  is  strengthened  by  bevelling  the  eavo- 


Fio.  49. 


Occlusal  fissuri   ill  an  iij.).!  ;  !.,(  ,i>(iid,  showing  direction  of  rods.    (About  80  X.) 

surface  angle,  so  that  the  rods  forming  the  margin  are  supported  by  at 
least  a  few  rods  which  are  covered  by  filling  material. 

In  cutting  out  the  fissures  on  the  occlusal  surfaces  of  molars  and 
Ijicuspids,  the  rods  are  inclined  centrally  from  the  axial  |)lane,  as  seen 
in  Fig.  49.  In  opening  a  fissure  the  lines  of  cleavage  will  not  be  in 
the  axial  plane,  but  sloj^ing  inward  toward  the  body  of  the  cusp,  in  the 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS. 


73 


direction  indicated  by  the  direction  of  the  cracks  in  Fig.  49.  The  outer 
ends  of  the  enamel  rods  must  be  shaved  away,  to  bring  the  plane  of 
the  enamel  wall  parallel  with  the  dentin  wall  or  into  the  axial  plane. 
When  this  has  been  done  a  strong  margin  has  been  formed,  for  the 

Fig.  50. 


Preparation  of  enamel  walls  in  occlusal  fissure  cavities  (the  same  as  Fig,  49). 

rods  which  form  the  point  of  the  cavo-surface  angle  are  supported  by 
the  piece  A,  B,  C(Fig.  50),  made  up  of  rods  resting  upon  sound  dentin 
and  covered  by  the  filling  material.  Often  the  angle  will  be  too  sharp, 
however,  and  the  cavo-surface  angle  should  usually  be  bevelled  to  pro- 
tect the  margin  from  accident.  This  illustration  may  be  taken  as  typ- 
ical of  occlusal  cavities. 


74  DEyTAL   HISTULOGY  ASD   OPERATIVE  DENTISTRY. 


Fi(i.  51. 


Prepantlioii  of  enamel  walls  m 


i:i\it_v   in  a  iiiular:   '.',  gingival   wall;  O,  occlusal  wall 
(About  70  X.J 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS.  75 

Fig.  51  shows  a  cavity  prepared  in  the  buccal  surface  of  an  upper 
molar.  The  occlusal  margin  is  placed  in  the  occlusal  half  of  the  middle 
third,  and  the  gingival  margin  in  the  gingival  half  of  the  gingival  third 

Fig.  52. 


2.  Wall  as  trimmed. 
Preparation  of  occlusal  wall  of  Fig.  51.    (About  70  X.) 

of  the  surface.  In  the  occlusal  wall  the  rods  are  inclined  occlusally 
about  8  centigrades  (28°)  from  the  horizontal  plane.  After  cleaving, 
the  broken  and  slivered  rods  should  be  shaved  away,  but  the  angle  can- 


76 


DENTAL  HISTOLOGY  ASD   OPERATIVE  DENTISTRY. 


iH)t  be  increased  witlumt  iiiakiii<;  tlit- margin  of  lilliiig  luiitcrial  too  thin; 
the  rods  forming  tlie  margin  should  therefore  be  protected  by  bevel- 
ling the  cavo-surfaco  angle.  At  the  gingival  wall  the  rods  are  inclined 
a})ioally  from  the  horizontal  plane  abont  6  centigrades  (20°).  The 
wall  should  be  shaved  in  that  plane,  increasing  the  angle  a  little,  and 
the  cavo-surface  angle  should  be  bevelled.  Fig.  52  shows  the  occlusal 
enamel  wall  alone,  after  cleaving  and  trimming  into  form.  Such 
enamel    walls   may   be  taken  as  typical  of  axial  surface  cavities,   the 

Fig.  53. 


structure  of  enamel  about  a  fissure  :  /?,  huccal  side  ;  L,  liiiRii: 


angle   of   the  enamel    with    the  dentin    wall   being  determined  by   the 
direction  of  the  enamel  rods  in  the  position  where  the  margin  is  laid. 

Grooves,  fissures,  and  pits  are  always  positions  of  weakness,  and 
when  a  cavity  ap})roaehes  a  groove  or  pit  a  good  margin,  histologically, 
cannot  be  prepared  without  cutting  beyond  it.  Fig.  53  shows  an 
occlusal  fissure  in  a  bicuspid,  which  illustrates  the  conditions  of  struct- 
ure characteristic  of  these  positions.  The  rods  are  inclined  toward 
the  fissure,  and  between  the  bottom  of  the  fissure  and  the  dentin  are 
verv  irregular.  If  a  cavity  wall  were  made  to  approach  this  fissure  from 
the  lingual  side,  so  as  to  come  to  the  dotted  line,  the  wall  would  have 
to  be  inclined  6  to  8  centigrades  (20°  to  28°)  from  the  axial  plane  toward 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS. 


77 


the  fissure,  and  then  the  cavo-surface  angle  bevelled,  when  the  condi- 
tions would  be  similar  to  those  in  the  wall  of  an  axial  surface  cavity, 
and  not  as  strong  as  the  location  requires.  Not  only  is  this  true,  but 
it  also  leaves  a  vulnerable  point  next  to  the  margin  of  the  filling — a 
point  of  liability.  Cutting  just  beyond  the  fissure,  the  wall  may  be 
left  in  the  axial  plane  and  have  an  ideally  strong  margin,  and  the 
point  of  liability   is    removed.       To    state   the   conditions    in    general 

Fig.  54. 


B  A 

Bucco-lingual  section  of  upper  bicuspid.    Enamel  is  broken  from  grinding .  Aio  B,  area  of  weak- 
ness for  enamel  margins.     (About  20  X.) 

terms,  a  strong  margin  is  more  easily  obtained  where  enamel  rods  are 
inclined  toward  the  cavity  than  where  they  are  inclined  away  from  the 
cavity. 

The  points  of  cusps  and  the  crests  of  marginal  ridges  are  positions  of 
strength  in  the  perfect  tissue ;  but  when  a  cavity  margin  approaches 
them  they  become  points  of  weakness,  because  it  is  impossible  to  sup- 
port properly  the  rods  which  form  the  margin.     Over  the  marginal 


78 


DESTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


ridges  are  many  short  rods  Avliidi  do  not  icacli  the  dentin,  and  these 
are  usually  very  much  twisted  about  each  otiier,  so  as  to  form  the 
strongest  possible  keystone   in   the   jieii'eet   strnctnre.      In   preparing  a 


Fi.;.  o5. 


Enamel  over  tip  of  dentin  cusp  :  D,  dentin  cusp,    f About  80  X.) 


margin  in  such  a  position  it  is  impossil)le  to  have  the  rods  which 
form  the  margin  reach  the  dentin  with  their  inner  ends,  and  these 
short  rods  are  sure  either  to  break  in  completing  the  operation  or  to 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS. 


79 


break  out  later.  The  arrangement  of  enamel  rods  in  such  positions  is 
to  be  borne  in  mind,  especially  when  extending  approximal  cavities  in 
incisors  toward  the  lingual  side  and  in  large  pit  cavities  in  incisors.  A 
similar  condition  is  found  over  the  points  of  the  cusps.  Fig.  54  shows 
a  bucco-lingual  section  of  an  upper  bicuspid.  It  will  be  noticed  that 
the  rods  forming  the  point  of  the  cusp  are  not  in  the  axial  plane,  and 

Fig.  56. 


Tip  (jf  an  incisor.    (About  50  X.) 


do  not  reach  the  tip  of  the  dentin  cusp,  but  reach  the  dentin  a  little 
way  down  on  the  outer  slope.  The  enamel  covering  the  tip  of  the 
dentin  contains  many  short  rods,  and  they  are  very  much  twisted  about 
each  other,  so  that  the  area  from  A  and  B  to  the  point  of  the  cusp  is  an 
area  of  weakness  for  the  cavity  margins.  If  the  margin  reaches  this 
area,  the  cusp  must  be  cut  away  and  the  enamel  wall  carried  out  in  the 
horizontal  plane.     Fig.  55  shows  this  area  more  highly  magnified,  and 


80 


DKNTAL   HISTOLOGY  AND   OPERATIVE  DESTISTHY. 


illustrates  the  structuro.      It  will  bo  noticed  that,  in  grinding,  some  of 
the  short  twisted  rods  have  broken  out  of  the  section. 

Fig.  56  shows  the  tip  of  an  incisor  in  labio-lingual  section,  and  is  of 
interest  in  relation  to  the  formation  of  margins  in  step  cavities  in  in- 
cisors. The  tip  of  this  tooth  has  been  worn  off  in  use.  The  illustration 
shows  that  the  great  inclination  of  the  rods  toward  the  axial  plane  in 
the  occlusal  third  of  the  incisors  is  such  as  to  bring  tiie  wear  almost  at 
right  angles  to  the  direction  of  the  rods. 

Dentin. 

The  structure  of  dentin  is  of  eom|»aratively  little  interest  in  the 
present  consideration,  as  its  histological  forms  do  not  diicetly  iuHueuee 

Fig.  57. 


Dentin  at  dento-enamel  junction,  showing  tubuk-s  cut  longitudinally:  /y^  dentinftl  ttibuli's  :  D, 
dentin  matrix.    (About  760  X.) 


the  cutting  of  the  tissue  in  the  excavation  of  cavities.  Its  histological 
forms  have,  however,  much  to  do  with  the  penetration  of  caries  and 
with  other  considerations  which  are  of  importance  to  the  intelligent 
practice  of  operative  dentistry. 


DENTIN. 


81 


Dentin  belongs  to  the  connective-tissue  group,  and  is  made  up  of 
a  solid  organic  matrix  impregnated  with  about  72  per  cent,  of  inorganic 
salts  ^  and  pierced  by  minute  canals  or  tubules,  which  radiate  from  a 
central  cavity  which  contains  the  remains  of  the  formative  organ,  or 
pulp.  The  minute  canals,  or  dentinal  tubules,  are  occupied  in  life 
by  protoplasmic  processes  from  the  odontoblastic  cells  which  form  the 
outer  layer  of  the  pulp.  Dentin  contains  two  kinds  of  organic  matter, 
the  contents  of  the  tubules  and  the  organic  basis  of  the  matrix.  The 
dentin  matrix,  after  the  removal  of  the  calcium  salts  by  acids,  yields 
gelatin  on  boiling  and  resembles  the  matrix  of  bone,  reacting  in  a  similar, 
though  not  identical,  way  with  staining  agents.  The  portion  of  the 
matrix  immediately  surrounding  the   tubules  shows  different  chemical 

Fig.  58. 


Dentin  showing  tubules  in  cross-section:  Z)<,  dentinal  tubules:  J),  dentin  matrix;  S,  shadow  of 
sheaths  of  Neumann.     (About  1150  X-) 

characteristics  from  the  rest  of  the  matrix,  resembling  elastin,  and  re- 
sisting the  action  of  strong  acids  and  alkalies  after  the  rest  of  the 
tissue  has  been  destroyed.  This  portion  of  the  matrix  surrounding  the 
tubules  and  lying  next  to  the  fibrils  is  known  as  the  sheaths  of  Neumann. 
The  dentinal  tubules  are  from  1.1  to  2.5  microns  in  diameter,  and 
are  separated  from  each   other  by  a  thickness  of  about  10  microns  of 

*  Von  Bibra  gives  the  following  analysis  of  dentin  : 

Organic  matter 27.61 

Fat 40 

Calcium  phosphate  and  fluorid 66.72 

Calcium  carbonate .    .    .    3.36 

Magnesium  phosphate 1.08 

Other  salts 83 

6 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


dentin  matrix.  This  is  fairly  uiiifonn  thnniiilioiit  the  (U-ntin.  The 
character  of  the  tubules  is  different  in  tiie  crown  and  root  portions. 
In  the  crown  tlie  tubules  branch  but  little  throuijh  most  of  their 
course  ;  but  in  the  outer  part,  close  to  the  enamel,  they  branch  and 
anastomose  with  each  other  (piite  freely.  Fig.  57  shows  a  held  of 
dentin  just  beneath  the  enamel,  as  seen  with  a  high  power,  and  shows 
the  diameter  of  the  tubules,  their  branching,  and  the  amount  of  matrix 
between  one  tubule  and  the  next.  The  relation  of  one  tubule  to  each 
other  is  shown  also  in  sections  cut  at  right  angles  to  their  direction 
(Fig.  58).     In  the  crown  portion  the  tubules  pass  from  the  pulp  chamber 

Fk;.  r)9. 


Crown  of  a  molar,  mesio-distal  section,  showing  peiuiruti  in    t 
tin;  B,  line  of  abrasion  :  P.  i>ulp  cliainlnT. 


iliug  den- 


Atioul  JO  ■  .) 


to  the  dento-enamel  junction  in  sweeping  curves,  so  as  to  enter  the  pulp 
chamber  at  right  angles  to  the  surface,  and  end   next  to  the  enamel  at 

right  angles  to  that  surface.    This  produces  S-  or  F-shaped     \    or 

curves,  which  are  known  as  the  primary  curves  of  the  tubules.  Through- 
out their  course  the  tubules  are  not  straight,  but  show  a  great  many 
wavy  curves,  known  as  the  secondary  curves.  These  appear  as  waves 
when  seen  in  longitudinal  sections,  but  are  really  the  effect  of  an  open 
spiral  direction,  as  is  seen  by  changing  the  focus  of  the  microscope  in 
studying  sections  cut  at  right  angles  to  the  direction  of  the  tubules. 


Dentin  from  the  root,  showing  tubules  cut  longitudinally.     (About  700  X.) 


Fro.  61. 


Dento-enamel  junction.    (About  70  X-) 


84 


DESTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


The  l)r:inclu's  tlirontjjlKMit  llicir  Iciiiitli  ai'c  fi'W  and  small,  ami  are  jiivcii 
ofl'  at  an  acute  aii«ile  to  tlie  direetioii  ni"  tlie  tiihtile  ;  l)Ut  just  Ix'fore  the 
eiiaiiK'l  i.s  ri'aehed  tlie  tubules  I'ork  and  branch,  pr()ducin<2;  an  a|)])earance 
similar  to  the  delta  of  a  river.  These  brunehe.s  are  j^iven  of!"  Irom  the 
tubules  for  some  little  distance  back  from  the  enamel,  and  thev  anasto- 
mose with  other  tubules  very  freely.  The  branching  of  the  tubules  in 
their  outer  portion  causes  the  spreading  of  caries  just  beneath  the 
enamel,  the   micro-organisms  growing   through  the  branches  from  tube 


Fi<i.  ()2. 


Interglobular  spaces  in  dentin:  J*;,  first  line  of  interglobular  spaces;  /p',  second  line  of  intir- 
globular  spaces.    (About  30  X.) 

to  tube,  and  so  spreading  sideways  beneath  the  enamel  plates,  and  then 
])enetrating  the  dentin  in  the  direction  of  the  tubules.  Fig.  59  shows 
the  penetration  of  caries  in  the  dentin.  It  will  be  noticed  that  in  decay 
starting  at  the  contact  point  there  has  been  more  spreading  under  the 
enamel  than  in  that  starting  at  the  gingival  line,  but  in  both  positions 
the  penetration  has  followed  the  direction  of  the  tubules. 

In  the  root  portion  the  tubules  pass  out  from  the  pulp  canals  at  right 
angles  to  the  long  axis  of  the  tooth  and  pass  directly  out  to  the  cemen- 
tum,  showing  only  the  secondary  curves.    Throughout  their  course  they 


DENTIN. 


85 


give  off  a  great  many  fine  branches  passing  through  the  matrix  in  all 
directions  from  tubule  to  tubule.  These  branches  are  so  numerous  that 
in  sections  which  have  been  mounted  in  such  a  way  as  to  leave  air  in 
them,  or  if  the  tubules  have  been  filled  with  coloring-matter,  they  give 
the  impression  of  looking  through  a  hazel  bush  ;  or  they  may  be  likened 
to  the  fine  rootlets  of  a  plant.  These  fine  branches  are  shown  in 
Fig.  60,  and  the  character  of  the  dentin  in  the  root  portion  is  to  be 
compared  with  that  in  the  crown  portion  as  shown  in  Fig.  57.     The 

Fig.  63. 


Granular  layer  of  Tomes  :  i,  lacunae  of  cementum ;  e<,  granular  layer  of  Tomes ;  /gr,  interglobular 

spaces.    (About  200  X.) 

outermost  layer  of  the  dentin  next  to  the  cementum  contains  many 
small  irregular  spaces,  which  connect  with  the  dentinal  tubules  and  give 
to  the  tissue  when  seen  with  low  powers  a  granular  appearance.  This 
layer  was  first  described  by  John  Tomes  as  the  granular  layer,  and  has 
since  been  usually  called  the  granular  layer  of  Tomes.  The  spaces  of 
the  granular  layer  are  probably  filled  by  the  enlarged  ends  of  the  den- 
tinal fibrils.  The  same  appearance  is  sometimes  seen  beneath  the  enamel, 
but  is  never  as  well  marked  as  next  to  the  cementum. 

The  dentin  at  the  dento-enamel  junction  seldom  presents  a  smooth 
surface,  but  the  inner  surface  of  the  enamel  plate  shows  rounded  pro- 


86 


DENTAL  HISTOLOGY  AND   OPERATIVE  DEyTISTRY. 


jections,  between  which  the  dentin  extends.  In  sections  this  gives  to 
the  (lento-enamel  jnnotion  a  scaUoped  appearance,  as  shown  in  Fig.  61  ; 
and  often  the  deceptive  appearance  of  the  dentinal  tubules  penetrating 
for  a  short  distance  between  the  enamel  rods. 

In  many  specimens  made  by  grinding  dried  teeth  large  irregular 
spaces  are  very  conspicuous  in  the  dentin.  They  usually  occur  in  lines 
or  zones  at  about  uniform  depth  from  the  surface.  These  have  been 
called  the  interglobular  spaces.  They  are  really  not  spaces  at  all,  but 
are  areas  of  imperfect  development  in  which  the  dentin  matrix  has  not 

Fio.  64. 


F 


JX 


-■'■Ay 


-m^. 


—A 


Uv  \i 


fh 


Secondary  dentin  :  A,  margin  of  primary  dentin,  showing  a  few  of  the  tubules  continuing  into  the 
secondary  dentin  ;  P,  pulp  chamber,     (.\bout  SO  X.) 

been  calcified.  Tiie  dentinal  tubules  pass  through  them  without  inter- 
ruption. In  a  dried  specimen  the  organic  matrix  shrinks,  and  the 
resulting  s})ace  becomes  filled  with  the  debris  of  grinding,  so  as  to  give 
the  appearance  of  black  spaces.  Fig.  62  shows  two  quite  distinct  layers 
of  interglobular  spaces,  the  second  much  more  marked  than  the  first; 
and  in  the  enamel  at  a  position  corresponding  to  the  first  is  seen  an  im- 
perfection of  structure  marked  by  the  very  dark  stratification  band. 
This  is  shown  best  in  the  region  of  the  cusp  (Fig.  44)  from  the  same 
section.  Interglobular  spaces  in  the  root  portion  of  the  dentin  are 
shown  in  Fig.  63,  close  to  tlie  granular  layer  of  Tomes. 


PULP.  87 

The  formation  of  dentin  is  not  complete  at  the  time  of  eruption  of 
the  tooth,  but  continues  for  an  indefinite  period,  thickening  the  layer  of 
dentin  at  the  expense  of  the  pulp.  When  the  typical  amount  of  den- 
tin has  been  formed  the  growth  ceases,  and  does  not  begin  again  unless 
excited  by  some  irritation  to  the  pnlp  or  the  pulp  of  some  other  tooth 
of  the  same  side,  which  leads  to  the  formation  of  secondary  dentin. 
Secondary  dentin  is  never  as  perfect  in  structure  as  primary  dentin ; 
the  tubules  are  smaller,  fewer,  and  much  more  irregular.  Often  in 
ground  sections  several  periods  of  formation  can  be  determined  by  dif- 
ferences of  structure,  each  deposit  becoming  successively  more  and  more 
imperfect  in  structure.     This  is  shown  in  Fig.  64. 

Pulp. 

The  dental  pulp  is  the  soft  tissue  occupying  the  central  cavity  of  the 
dentin.  It  is  made  up  of  embryonal  connective  tissue  and  contains  a 
large  number  of  bloodvessels  and  nerves.  Like  all  connective  tissues, 
the  intercellular  substance  is  large  in  amount  and  the  cells  are  widely 
scattered  in  this  soft,  jelly-like  tissue,  which  contains  but  few  fibers. 
We  recognize  four  kinds  of  cells  in  the  pulp :  the  odontoblasts,  form- 
ing the  outer  surface  of  the  pulp  next  to  the  dentin ;  and  round,  spindle- 
shaped,  and  stellate  connective-tissue  cells. 

AEEANGEMENT    OF    CELLS. 

The  odontoblasts  are  tall  columnar  cells,  sometimes  club-shaped,  and 
in  older  tissues,  which  have  ceased  to  be  functional,  sometimes  becoming 
almost  spherical.  They  form  a  continuous  layer  over  the  entire  surface 
of  the  pulp,  being  everywhere  in  contact  with  the  dentin.  The  layer 
has  been  called  the  membrana  eboris,  or  the  "  membrane  of  the  ivory." 

The  nuclei  of  the  odontoblasts  are  large  and  oval,  containing  a  large 
amount  of  chromatin,  and  are  very  diiferent  from  the  nuclei  of  ordinary 
connective-tissue  cells. 

Three  kinds  of  processes  have  been  described  in  connection  with  the 
odontoblasts  : 

1.  The  dentinal  fibril  processes,  or  fibers  of  Tomes.  These  are  long, 
slender  protoplasmic  processes  projecting  from  the  dentin  end  of  the 
cell  into  a  dentinal  tubule,  and  running  through  the  tubule  to  the  outer 
surface  of  the  dentin.  Usually  there  is  but  one  fibril  extending  from 
each  odontoblast,  but  sometimes  two  can  be  seen,  extending  into  two 
tubules.  These  fibrils  can  be  demonstrated  in  decalcified  sections  or 
by  removing  the  pulp  from  a  recently  extracted  tooth  by  cracking  the 
tooth  and  carefully  lifting  the  pulp  out  of  the  pulp  chamber,  and  then 
either  teasing  or  sectioning.      Fig.  65  shows  the  fibrils  projecting  from 


88  DESTAL   HISTOLOGY  AXD   OPERATIVE  DENTISTRY. 

tlie  surfacr  ;  hut  in  tliis  s^vtion  the  cut  was  ii(»t  in  the  diivctioii  of  the 
long  axis  of  the  odontobhists,  but  obliquely  through  them.  Fig.  66 
(from  a  photograph  bv  Kose)  shows  the  form  of  the  otlontoblasts  in  a 


Odontoblasts.  The  section  cuts  obliquely  thrriu<;h  the  odontoblasts:  /",  fibrils:  X,  nuclei 
of  odontoblasts;  .V,  nuclei  of  connective-tissue  cells;  )(',  layer  of  Weil,  not  well  shown. 
(About  80  X.) 

young  tooth  in  which  formation  of  dentin  is  actively  progressing,  with 
the  fibrils  in  the  dentinal  lul)ules. 

2.  Lateral  ])rocesses  projecting  from  the  sides  of  the  cells  and  unit- 
ins:  one  with  another  in  the  formation  of  the  laver. 

3.  Pulpal  processes,  projecting  from  the  pulpal  ends  of  the  odonto- 
blasts into  the  layer  of  AVeil. 

The  odontoblasts,  as  the  name  indicates,  are  the  dentin-forming 
cells.  They  superintend  the  formation  and  calcification  of  the  dentin 
matrix,  the  fibril  being  left  behind  surrounded  by  the  formed  tissue. 
Whether  the  fibrils  have  any  share  in  the  formation  and  calcification  of 
the  dentin  matrix  has  been  a  matter  of  controversy. 

The  relation  of  the  fibrils  to  the  transmission  of  sensation  is  also  a 
matter  of  dispute  ;  but  at  present  the  weight  of  evidence  is  that  they 
in  some  way  transmit  impressions  to  the  sensory  nerves  of  the  pulp. 

Just  beneath  the  layer  of  odontoblasts  is  a  zone  wliich  contains  very 
few  connective-tissue  cells.  In  thin  sections,  esjK'cially  in  the  body  of 
the  pulj),  this  appears  as  a  clear  layer  about  half  as  thick  as  the  layer 
of  odontoblasts.     It  is  known  as  the  la^er  of  Weil.     Just  beneath  the 


PULP. 


89 


layer  of  Weil  the  connective-tissue  cells  are  especially  numerous  and 
form  a  more  or  less  distinct  layer  of  closely  placed  cells.  In  the  rest 
of  the  body  of  the  pulp  the  cells  are  about  uniformly  distributed  through- 
out the  intercellular  substance.  These  connective-tissue  cells  are  of  the 
characteristic  forms^  rather  small,  containing  a  small  but  deep-staining 
nucleus,  the  protoplasm  stretching  out  into  slender  projections  in  two 
directions  to  form  the  spindle  cells,  or  in  more  than  two  directions  to 
form  the  stellate  cells.  The  stellate  forms  are  more  common  in  the 
body  of  the  pulp,  the  spindle  form  in  the  canal  portions.     The  round 

Fig.  66. 


Odontoblasts  and  forming  dentin:  E,  forming  enamel;  D,  forming  dentin;   0,  odontoblasts; 
Dp,  body  of  dental  papilla.    (From  photomicrograph  by  Rose.) 

cells  are  comparatively  few  in  number,  and  are  probably  young  cells 
which  have  not  yet  acquired  the  adult  form. 


BLOODVESSELS    OF    THE    PULP. 

The  blood-supply  of  the  pulp  is  extremely  rich,  several  arterial  ves- 
sels entering  in  the  region  of  the  apex  of  the  root,  often  through  several 
foramina.  These  large  vessels  extend  occlusally  through  the  central  portion 
of  the  tissue,  giving  oif  many  branches  which  break  up  into  a  very  close 
and  fine  capillary  plexus  (Fig.  67).  From  the  capillaries  the  blood  is 
collected  into  the  veins,  which  pass  apicaliy  through  the  central  portion 
of  the  tissue.  A  very  striking  peculiarity  of  the  bloodvessels  of  the  pulp 
is  the  thinness  of  their  walls.    Even  the  large  arteries  show  scarcely  any 


!»0  DENTAL  HISTOLOGY  AND  OPERATIVE  DENTISTRY. 

Fk).  67. 


Diagram  of  the  bloodvessels  of  the  pulp.     (Stowell.) 

condensation  of  fibrous  tissue  around   them   to  form   tlie  usual   adven- 
titious layer,  and  usually  contain  but  a  .single  involuntary  muscle  fiber 

Fig.  68. 


'< 


'> 


f   » 


J   ♦ 


rf> 


.  ^':' 


V 


-o 

-Bl 

-N 


v>» 


A  pulp  bloodvessel,  showing-  the  thin  wall :  C,  blood  corpuscles  in  the  vessel ;  Bl,  bloodvessel  wall 
showing  nuclei  of  endothelial  cells;  N,  nuclei  of  connective-tissue  cells  in  the  body  of  the 
pulp ;  /,  intercellular  substance,  showing  a  few  fibers.     (About  2fX)  X.) 

representing  the  media,  while  the  walls  of  even  the  large  veins  are  made 
up  of  only  the  single  layer  of  endothelial  cells  forming  the  intima,  and 


PULP.  91 

are  in  structure  like  large  capillaries  (Fig.  68).  This  peculiarity  of  the 
bloodvessel  walls  is  of  great  importance,  as  it  renders  the  tissue  specially 
liable  to  such  pathologic  conditions  as  hyperemia  and  inflammation. 

NEEVE   OF     THE    PULP. 

Several  comparatively  large  bundles  of  medullated  nerve  fibers,  coi^.- 
taining  from  six  or  eight  to  fifteen  or  twenty  fibers,  enter  the  pulp 
in  company  with  the  bloodvessels  and  pass  occlusally  through  the 
central  portion  of  the  tissue.  These  bundles  branch  and  anastomose 
with  each  other  very  freely.  Most  of  the  fibers  lose  their  medullary 
sheath  before  reaching  the  layer  of  Weil,  in  which  position  they  form  a 
plexus  of  non-medullated  fibers  ;  from  these  fibers  free  endings  are  given 
off,  which  penetrate  between  the  odontoblasts.  In  some  cases  these 
have  been  followed  over  on  to  the  dentinal  ends  of  the  odontoblasts, 
but  in  no  instance  have  they  been  followed  into  the  dentinal  tubules. 

THE    FUNCTIOlSrS    OF   THE    PULP. 

The  pulp  performs  two  functions,  a  vital  and  a  sensory. 

The  vital  function  is  the  formation  of  dentin,  and  is  performed 
by  the  layer  of  odontoblasts.  This  is  the  principal  function  of  the 
pulp,  and  it  is  first  manifested  in  the  development  of  the  tooth  before 
the  dentinal  papilla  is  converted  into  the  dental  pulp  by  being  inclosed 
in  the  formed  dentin.  After  the  tooth  is  fully  formed  the  vital  func- 
tion is  not  manifested  unless  the  pulp  is  stimulated  by  some  excitation 
affecting  trophic  centres  and  which  causes  the  formation  of  secondary 
dentin.  There  are  some  exceptions  where  the  formation  is  entirely 
local. 

The  Sensory  Function. — In  regard  to  sensation,  the  pulp  resembles 
an  internal  organ.  It  has  no  sense  of  touch  or  localization,  and  re- 
sponds to  stimuli  only  by  sensations  of  pain.  The  pain  is  usually 
locahzed  correctly  with  reference  to  the  median  line,  but,  aside  from 
that,  is  localized  only  as  it  is  referred  to  some  known  lesion.  If  several 
pulps  on  the  same  side  of  the  mouth  and  in  teeth  of  both  the  upper 
and  lower  arches  were  exposed  so  that  they  could  be  irritated  without 
impressions  reaching  the  peridental  membrane,  and  the  patient  were 
blindfolded,  it  would  be  impossible  for  him  to  tell  which  of  the  pulps 
was  touched.  The  pain  originating  from  a  tooth  pulp  may  be  referred 
to  the  wrong  tooth  or  to  almost  any  point  on  the  same  side  supplied  by 
the  fifth  cranial  nerve. 

The  pulp  is  especially  sensitive  to  changes  of  temperature,  but  is 
incapable  of  differentiating  between  heat  and  cold  ;  this  fact  is  often 
made  use  of  in  differential  diagnoses  (see  Chapter  XVI.).     The  pulp  is 


92 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


also  very  sensitive  to  trauinatie  ami  elieniical  irritations,  even  when 
these  are  conveyed  to  it  throno;!!  the  auciicy  of  the  dentinal  til)rils.  Dr. 
Huber  has  suggested  '  that  this  transmission  may  he  aceomplished  hv 
the  traumatic  or  chemical  action  upon  the  lihrils  setting  up  metabolic 
changes  in  the  odontoblastic  cells,  which  act  as  stimuli  to  the  sensory 
nerves  ending  between  the  cells  of  that  layer, 

Cementum. 

The  cementum  covers  the  surface  of  the  dentin  ajucally  from  the 
border  of  the  enamel,  lapping  slightly  over  the  enamel  at  the  gingival 
margin  (Fig.  69).     It  forms  a  layer,  thickest  in  the  apical  region  and 

Fig.  69. 


Gingival  border  of  enamel,  sho\\ 


1  riapping  it:  /?,  enamel ;  C,  cementum  ;  D, 
viMiut  10  X.) 


between  the  roots  of  bicuspids  and  molars,  and  becoming  thinner  as  the 
gingival  line  is  approached.  The  cementum  resembles  subperiosteal 
bone  in  structure,  but  differs  from  it  in  the  character  and  arrangement 
of  the  lacunae  and  in  the  absence  of  Haversian  systems ;  the  layers,  or 
lamellae,  of  the  cementimi  also  are  less  uniform  in  character  than  those 
of  bone. 

The  function  of  the  cementum  is  to  furnish  attachment  for  the 
fibers  of  the  peridental  membrane  which  holds  the  tooth  in  its  position. 
The  surrounding  tissues  are  never  in  physiologic  connection  with  the 
outer  surface  of  the  dentin,  except  to  form  cementum  over  it  or  to 
remove  its  substance  by  absorption  ;  and  when  absorption  of  the  dentin 

'  Dental  Cosmo.%  October,  1S9S. 


CEMENTUM. 


93 


has  occurred  on  the  surface  of  a  root  it  is  never  repaired  except  by  the 
formation  of  cementum  to  fill  up  the  cavity  and  reattach  the  membrane. 
The  cementum  is  intermittently  formed  during  the  functioning  of 
the  tooth,  being  added  layer  after  layer  over  the  entire  surface  of  the 
root,  the  difference  in  thickness  of  the  tissue  in  the  gingival  and  apical 
portions  being  chiefly,  though  not  entirely,  due  to  the  difference  in 
thickness  of  each  layer  in  the  two  positions  (Figs.  69,  70),  The 
cementum  on  the  roots  of  newly  erupted  teeth  is  thin,  and  on  the  roots 
of  teeth  of  old  persons  is  thick.     This  continued  formation  of  cementum 


Fig.  70. 


Cementum  near  the  apex  of  the  root :  Gt.  granular  layer  uf  Tomes ;  L,  lacunae  ,  h,  point  at  which 
fibers  were  cut  off  and  reattached.    (About  &iX.) 


is  due  to  the  necessity  for  change  and  reattachment  of  the  fibers  of  the 
membrane. 

In  the  gingival  portions,  where  the  cementum  is  thin,  the  tissue  is 
clear  and  apparently  structureless,  and  usually  contains  no  lacunae ; 
while  in  the  apical  half  and  between  the  roots  the  lacunae  are  numerous. 
In  general,  wherever  the  lamellae  are  thin,  the  lacunae  are  absent ;  but 
where  the  lamellae  are  thick  they  are  found.  The  canaliculi  which 
radiate  from  the  lacunae  are  not  as  regular  as  in  the  case  of  the  lacunae 
of  bone.  Sometimes  they  are  numerous,  sometimes  few ;  they  may 
extend  from  a  lacuna  in  all  directions,  or  they  may  be  confined  to  one 
side,  usually  the  side  toward  the  surface  of  the  cementum  (Fig.  71). 


94 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY 

Fi.i.  71. 


Thick  lamella-  of  cementum  with  many  lacuiicf.  uiiiiii;  mi  iiMMUptiou  in  dentin:  L,  lacunae:  Jl, 
Howship's  lacunae  filled  ;  D,  dentin.    (About  JoOx.) 


Fig.  72. 


Two  fields  of  cementum  showing  penetrating  libers:  (jrl.  granular  layer  of  Tomes;  C,  cementum 
not  showing  fibers ;  /",  penetrating  fibers.    (About  54  X.) 


PERIDENTAL  MEMBRANE.  95 

The  cementum  is  penetrated  through  all  its  layers  by  fibers  of  the 
peridental  membrane  which  have  been  imbedded  in  the  matrix  of  the 
tissue  and  calcified  along  with  it.  The  first  layer, — that  is,  the  one  next 
to  the  dentin, — is  usually  structureless  and  shows  no  fibers  in  it,  at 
least  in  its  inner  half.  In  ground  sections  the  imbedded  fibers  often 
appear  in  a  number  of  layers,  while  they  are  not  apparent  in  the  rest 
of  the  thickness.  This  is  because  just  before  and  just  after  the  forma- 
tion of  the  layers  in  which  they  appear  the  fibers  were  cut  off  and 
reattached,  changing  their  direction,  so  that  in  the  other  layers  the 
fibers  are  cut  transversely  or  obliquely.  This  is  illustrated  in  Fig,  72. 
These  imbedded  fibers  are  very  numerous  in  some  places.  If  properly 
stained,  the  tissue  seems  almost  a  solid  mass  of  fibers.  In  ground  sec- 
tions these  have  sometimes  been  mistaken  for  minute  canals  from  the 
fact  that  they  are  not  always  as  fully  calcified  as  the  cementum  matrix, 
and  shrinkage  causes  the  appearance  of  little  open  canals. 

Hypertrophies  of  the  cementum  (formerly  often  called  exostoses,  or 
excementoses)  are  very  common.  The  increased  thickness  may  be  of 
one  lamella  or  of  several  lamellae  in  the  region  of  the  hypertrophy,  or 
all  of  the  layers  from  first  to  last  may  take  part  in  it.  Small  local 
thickenings  of  a  single  lamella  are  seen  in  connection  with  the  peri- 
dental membrane  wherever  a  specially  strong  bundle  of  fibers  is  to  be 
attached  to  the  root  to  support  the  tooth  against  some  special  strain. 

Peridental    Membrane. 

The  peridental  membrane  may  be  defined  as  the  tissue  which  fills 
the  space  between  the  root  of  the  tooth  and  the  bony  wall  of  its 
alveolus,  surrounds  the  root  occlusally  from  the  border  of  the  alveolus, 
and  supports  the  gingivus.  It  has  been  referred  to  under  many  names, 
as  pericementum,  dental  periosteum,  alveolo-dental  periosteum,  etc. 
While  this  tissue  performs  the  functions  of  a  periosteum  for  the  bone 
of  the  alveolus,  it  differs  in  structure  from  the  periosteum  in  any 
position,  so  that  any  name  including  the  word  periosteum  or  implying 
a  double  membrane  should  be  avoided. 

The  peridental  membrane  belongs  to  the  class  of  fibrous  membranes, 
and  is  made  up  of  the  following  structural  elements : 

1.  Fibers.  2.  Fibroblasts.  3.  Cementoblasts.  4.  Osteoblasts.  5. 
Osteoclasts.  6.  Epithelial  structures  which  have  been  called  the  glands 
of  the  peridental  membrane.     7.  Bloodvessels.     8.  Nerves. 

The  peridental  membrane  performs  three  functions  :  a  physical 
function,  maintaining  the  tooth  in  relation  to  the  adjacent  hard  and 
soft  tissues;  a  vital  function,  the  formation  of  bone  on  the  alveolar 
wall   and   of  cementum   on   the   surface  of  the   root;  and  a  sensory 


06 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


function,  the    sense  of  touch   for   the  tooth  being  exclusively  in    this 
membrane. 

The   fibrous  tissue  of  the  membrane   is  of  the   Avhite   variety,  and 
may  be  divided  into  two  classes,  the  principal  fibers  and  the  indifferent  or 


Fig.  73. 


-4;).  -1 


Diagram  of  the  fibers  of  the  peridental  membrane  :  6,  gingival  portion :  Al,  alveolar  portion  ;  Ap, 
apical  portion.    (From  a  photograph  of  a  section  from  incisor  of  sheep.) 


interfibrous  tissue.     The  principal  fibers  may  be  defined  as  those  which 
spring  from  the  cementum  and  are  attached  at  their  other  end  to  the 


PERIDENTAL  MEMBRANE. 


97 


bone  of  the  alveolar  wall,  to  the  outer  layer  of  the  periosteum  covering 
the  surface  of  the  alveolar  process,  to  the  cementum  of  the  approximating 


Fig.  74. 


Longitudinal  section  of  peridental  membrane  from  young  sheep,  showing  iibers  penetrating 
cementum:  D,  dentin;  C,  cementum,  showing  imbedded  fibers;  F,  fibers  running  to  outer 
layer  of  periosteum  covering  the  alveolar  process ;  F',  fibers  running  to  the  bone  at  the  border 
of  the  process ;  B,  bone.    (About  80  X.) 

tooth,  or  become  blended  with  the  fibrous  mat  of  the  gum  supporting 
the  epithelium.     They  were  so  called  by  Dr.  Black,  not  only  because 

7 


98 


DEMAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


they  form  the  j)riiK'ipal  bulk  of  the  tissue,  but  tliey  also  perform  the 
principal  function  of  the  membrane,  the  support  of  the  tooth  and  sur- 
rounding tissues.  The  interfibrous  tissue,  also  of  the  white  variety  but 
made  uj)  of  smaller  and  more  delicate  fibers,  is  ft)und  tilling  spaces 
between  the  principal  fibers  and  surrounding  and  accompanying  the 
bloodvessels  and  nerves. 

For  convenience  of  description  and  study,  the  peridental  membrane 
is  divided  into  three  portions  :  {\\q  <jin<jlval,  that  portion  which  surrounds 
the  root  occlusally  from  the  border  of  the  alveolar  process  ;  the  alveolar, 
the  portion  from  the  border  of  the  process  to  the  apex  of  the  root ;  and 


Fi(i.  7 


Longitudiiiiil  section  of  the  peridental  membrHiie  in  the  gingival  portion-  D,  dentin;  N, 
Nasmyth's  niemhrane;  C,  cenientum ;  F,  fihers  supporting  the  Ringivus;  F^,  fibers  attached 
to  the  outer  layer  of  the  periosteum  over  the  alveolar  process ;  F^,  fibers  attached  to  the  bone 
at  the  rim  of  the  alveolus ;  B,  bone.    (About  30  X.) 

the  apical  portion,  surrounding  the  apex   of  the   root   and  filling  the 
apical  region  (Fig.  7o). 

The  principal  fibers  spring  from  the  cementura,  the  cementoblasts 
building  up  the  matrix  around  them  and  then  calcifying  both  matrix 
and  fibers,  in  this  way  implanting  their  ends  into  the  surface  of 
the  root.  In  Fig.  74  the  fibers  are  seen  passing  through  the  last- 
formed  layer  of  cementum.  In  most  positions  the  fibers  as  they  spring 
from  the  cementum  appear  as  well-marked  bundles  of  fine  fibers.  A 
short  distance  from  the  surface  of  the  root  they  break  up  into  smaller 
bundles,  which  interlace  and  are  reunited  into  larger  buadles,  to  be 


PERIDENTAL  MEMBRANE. 


99 


attached  at  their  other  extremity  to  the  bone,  cementum,  or  fibrous 
tissue. 

To  arrive  at  an  understanding  of  the  arrangement  of  the  fibers  of 
the  peridental  membrane,  they  must  be  studied  in  both  longitudinal  and 
transverse  sections.  In  longitudinal  sections  of  the  membrane,  in  the 
gingival  portion  (Fig.  75),  the  fibers  springing  from  the  cementum  at 
the  gingival  line  pass  out  for  a  short  distance  at  right  angles  to  the 
long  axis  of  the  tooth  and  then  bend  sharply  to  the  occlusal,^  passing 

Fig.  76. 


Transverse  section  I'f  the  jioridental  membrane  in  the  gingival  portion  (from  sheep):  E,  epi- 
thelium :  /•;  fibrous  tissue  of  gum  ;  B,  point  where  peridental  membrane  fibers  are  lost  in  fibrous 
mat  of  the  gum ;  P,  pulp ;  F',  fibers  extending  from  tooth  to  tooth.    (About  30  X.) 


into  the  gingivus  to  support  it  and  hold  it  closely  against  the  neck  of 
the  tooth.  These  fibers  are  most  numerous  on  the  lingual  side,  where 
food  is  brought  against  the  gingivus  with  force  in  mastication  and  tends 
to  crush  it  down.  In  the  middle  of  the  gingival  portion  the  fibers  pass 
out  at  right  angles  to  the  axis  and  are  blended  with  the  fibrous  mat  of 
the  gum  on  the  labial  and  lingual  sides,  or  are  attached  to  the  cementum 
of  the  adjoining  teeth  on  the  approximal  sides.     A  little  farther  from  the 

^  In  describing  the  direction  and  inclination  of  peridental  membrane  fibers  they  are 
always  traced  from  the  cementum  to  the  bone,  the  angle  with  the  horizontal  plane  being 
formed  at  the  surface  of  the  cementum. 


100 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


gingival  line  the  fibers  are  inclined  ^-^lightly  apically,  j)a.<^ing  over  the 
border  of  the  process  to  be  attached  to  the  onter  layer  of  the  periosteum. 
These  fibers  are  specially  large  and  strong.  Just  at  the  rim  of  the 
alveolus  the  fibers  are  inclined  slightly  apioally  and  are  inserted  into 
the  bone,  forming  the  edge  of  the  process. 

In  transverse  sections  of  the  membrane  in  the  gingival  ])(irti(m  (Fig. 
76)  the  fibers  spring  from  the  ccmcntum  in  large  bundles;  at  the  centre 
of  the  labial  surface  they  extend  directly  outward,  breaking  up  into 
smaller  bundles,  passing  around  bloodvessels  and  bundles  of  fibers,  and 
blending  with  the  fibrous  tissue  supporting  the  ej)ithelium.  Passing 
mesially  and  distally  toward  the  corners  of  the  root,  the  fibers  swing 
around  laterally  and  pass  to  the  cementnm  of  the  next  tooth.     On  the 


Fig.  77. 


Fibers  at  the  border  of  the  alveolar  process  (from  sheep) :  D,  dentin ;  C,  cementum ;  F,  fibers  ex- 
tending from  cementum  to  bone;  ii/,  bloodvessel;  B.hone.    (About  80 y.) 


approximal  sides  the  fibers  suddenly  divide  into  smaller  bundles,  which 
wind  in  and  out  around  bloodvessels,  and  bundles  of  fibers  whieh  pass 
into  the  gingivus  and  are  reunited  into  large  bundles  to  be  inserted  into 
the  cemeiltum  of  the  next  tooth.  On  the  lingual  side  the  arrangement 
is  like  that  of  the  labial,  except  that  the  distance  to  which  the  fibers  of 
the  membrane  can  be  followed  before  they  are  lost  in  the  fibrous  mat  of 
the  gum  is  usually  greater  than  on  the  labial. 

In  the  occlusal  third  of  the  alveolar  portion  of  the  membrane  the 
fibers  pass,  at  right  angles  to  the  axis  of  the  tooth,  directly  from  the 
cementum  to  the  bone.  In  this  position  the  fibers  are  large  and  do  not 
break  up  into  smaller  bundles,  but  the  original  fibers  can  be   followed 


PERIDENTAL  MEMBRANE. 


101 


Fig.  78. 


M. 

Per. 
Al. 

Pd. 


Al. 


Om. 


Cm. 


Al. 


Transverse  st-ctiuii  uf  the  peridental  membrane  in  the  occlusal  third  r-f  tlie  alveolar  portion 
(from  sheep) :  M,  muscle  fibers ;  Per,  periosteum ;  Al,  bone  of  the  alveolar  process  ;  Pd,  peri- 
dental membrane  fibers ;  P,  pulp ;  D,  dentin ;  Cm,  cementum. 


102  DENTAL   IITSTOLOOY  AND   OPERATIVE  DENTISTRY. 

unintcrriiptoclly  I'nun  the  cemcntuni  to  the  bone  (Figs.  74  and  77). 
In  the  middle  third  the  fibers  are  inelined  occlusally,  and  this  inclina- 
tion increases  as  the  apical  third  is  approached.  In  the  apical  third 
the  inclination  is  greatest,  and  the  fibers  as  they  arise  from  the  cemen- 
tum  are  very  large  and  break  up  into  fan-shaj)ed  fasciculi  as  they  pass 
across  to  the  bone.  In  the  apical  portion  the  fibers  radiate  from  the 
apex  in  all  directions  across  the  apical  region  and  spread  out  in  fan- 
shaped  bundles  like  those  in  the  apical  third  of  the  alveolar  portion. 

In  a  transverse  section  near  the  border  of  the  alveolus  (Fig.  78),  at 
the  centre  of  the  labial  surface  of  the  root,  the  fibers  are  seen  to  extend 
directly  out  from  the  surface  of  the  root  to  the  bone  of  the  process,  ex- 
cepting where  they  are  diverted  to  ])ass  around  bloodvessels.  Passing 
around  distally  at  the  corner  of  the  root,  the  fibers  swing  laterally  so  as 
to  be  almost  at  a  tangent  to  the  surface  of  the  root,  and  are  inserted 
much  farther  to  the  distal  on  the  wall  of  the  alveolus.  A  similar  ar- 
rangement is  noticed  at  the  other  corners  of  the  root,  though  these 
tangential  fibers  are  usually  more  marked  at  the  distal  than  at  the 
mesial  corners. 

Studying  the  arrangement  of  the  fibers  with  reference  to  the  physical 
function  of  the  membrane,  it  is  seen  to  be  the  best  that  could  be 
devised  to  support  the  teeth  against  the  force  of  mastication  and  to 
support  the  tissues  about  them.  In  the  gingival  portion  the  fibers 
passing  from  tooth  to  tooth  form  the  foundation  for  the  gingivae  between 
the  teeth  filling  the  interproximal  spaces;  so  that  if  these  fibers  are 
cut  oif  from  the  cementum,  by  extending  a  crown  band  too  far,  or  by 
the  encroachment  of  calculary  deposits  beginning  in  the  gingival  space, 
the  gingivus  drops  down  and  no  longer  fills  the  interproximal  s])ace.  In 
the  alveolar  portion  the  fibers  at  the  border  of  the  process  and  those 
at  the  apex  of  the  root  together  support  the  tooth  against  lateral 
strain,  while  those  in  the  rest  of  the  alveolar  portion  are  so  arranged 
as  to  swing  the  tooth  in  its  socket  and  support  it  against  the  force 
of  occlusion  (Fig.  73).  As  seen  from  the  transverse  section,  the  fibers 
of  the  occlusal  third  of  the  alveolar  j)ortion  are  so  arranged  as  to  sup- 
port the  tooth  against  forces  tending  to  rotate  it  in  its  socket. 

CETJ.rLAR    ELEMENTS    OF    THE    MEMP.RANE. 

The  fibroblasts  are  spindle-shaped  or  stellate  connective-tissue  cells 
which  are  found  between  the  fibers  as  they  are  arranged  in  bundles.  In 
sections  stained  with  hematoxylin  they  take  the  stain  deeply,  and  the 
fibers,  which  are  unstained,  are  differentiated  by  the  cells  lying  in  rows 
between  them.  The  number  of  filiroblasts  iji  the  membrane  decreases 
with  age.     They  are  large  and  numerous  in  the  membrane  of  a  newly 


PERIDENTAL  MEMBRANE. 


103 


erupted  tooth,  and  comparatively  small  and  few  in  the  membrane  around 
an  old  tooth.  This  is  characteristic  of  fibroblasts  in  other  positions. 
The  fibroblasts  are  shown  as  tbey  appear  iu  a  hematoxylin-stained 
section  with  low  powers  in  Fig.  79,  which  gives  part  of  the  membrane 
in  the  gingival  portion  between  two  teeth.  The  cells  are  seen  as  spindle- 
shaped  dots  which  mark  out  the  fibers  ;  at  F  they  are  seen  in  a  position 

Fig.  79. 


Fibers  and  fibroblasts  from  transverse  sectirm  of  nu-mbrane  :  F,  fibers  cut  transversely ;  F'^,  fibers 
cut  longitudinally,  showing  libroblasts.    (About  80  XO 

where  the  fibers  are  cut  transversely.     With  higher  powers  these  cells 
appear  as  in  Figs.  81  and  90. 

The  cementoblasts  are  the  cells  which  form  the  cementum,  and  are 
found  everywhere  covering  the  surface  of  the  root  between  the  fibers 


Fig.  80. 

^^ 

\^< 

^u^ 

^4. 

Cementoblasts.    (Drawing  by  Dr.  Black.) 


which  are  imbedded  in  the  tissue.  While  these  cells  perform  the  same 
function  for  the  cementum  as  the  osteoblasts  do  for  bone,  they  are  in 
form  very  different  from  the  osteoblasts.  The  cementoblasts  are  always 
flattened  cells,  sometimes  almost  scale-like,  and  when  seen  from  above 


104  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

:ire  vcrv  irrcL^uhir  in  outline.  'I'liis  irrcnularity  of  uiitliiu'  is  caused  by 
the  colls  Httiiiu;  ar.uiiid  the  attachetl  lihers  of  the  membrane  so  as  to 
cover  the  entire  surface  oi"  the  ceinentum  between  the  fibers.  Fig.  80, 
from  a  (b-awint!;  by  Dr.  lilack,'  shows  several  eementoblasts  as  seen 
when  isolated  by  teasing-.  The  eementoblasts  have  a  central  mass  of 
])rotoplasm  containint!;  an  oval  nucleus,  and  short  irregular  i)roeesses 
which  tit  around  the  fibers  as  these  spring  from  the  surface  of  the 
cementum.      Fig.    81   shows   them  in    section   perpendicularly   to   the 


Fui.  81. 


Tran.svcis 


r  (Icmfiits:    Fh,  filiroMasts  ;    /•>,  ci.itli 
X'liK'ntuin  ;  7^,  doiitin.     (  About  '.lOK  ,■;.) 


structures; 


surface  of  the  root,  where  they  are  crowded  between  the  fibers.  The 
eementoblasts  often  have  processes  projecting  into  the  cementum  like 
those  from  the  osteoblast,  but  processes  projecting  into  the  membrane 
have  never  been  demonstrated. 

In  the  formation  of  the  cementum  occasionally  a  cementoblast  be- 
comes inclosed  in  the  formed  tissue  filling  one  of  the  lacunae,  in  which 
position  it  becomes  a  cement  corpuscle. 

^  Periosteum  niul  Peri<h'nlal  Membrane. 


PERIDENTAL  MEMBRANE. 


105 


Fig.  82. 


H.B. 


Pd.B. 


Per. 


Border  of  growing  process :  Cm,  cementum  ;  Pd,  peridental  membrane ;  Pd.B,  solid  subperidental 
and  subperiosteal  bone  with  imbedded  fibers ;  Ms,  medullary  space  formed  by  absorption  of 
the  solid  bone;   if.£,  Haversian-system  bone  without  fibers;  Per,  periosteum.    (About  50 X-) 


106 


DENTAL   HISTOLOGY  AM)   OPKRATIVE  DENTISTRY. 


The  osteoblasts  of  tho  iiuinhi-aiic  rover  tlic  siirfhcc  of  the  bone, 
forming  the  wall  of  the  alveolus,  lyiiiti;  between  the  iilxrs  which  are 
bnilt  into  the  bone.  In  form  and  i'linetion  they  are  like  the  osteoblasts 
in  attached  portions  of  the  periosteum.  They  form  bone  around  the 
ends  of  the  peridental-membrane  fibers,  buildinj;  them  into  the  sub- 
stance  of   the   bone.       The   bone   tlius    formed    over    the   wall    of  the 

Fir;.  S3. 


P,I.M 


P'l.n^ 


H.li. 


rtenetratiii^  HIkts  in  bone  :  Pd.M,  peridental  membrane  ;  06',  osteobla.sts  of  peridental  membrane  : 
Ofc2,  osteoblasts  tif  medullary  space;  Pd.B,so\v\  subperidental  and  subperiosteal  bone  with 
imbedded  fibers;  3/*-,  medullary  space  formed  by  absorption  of  the  solid  subperidental  bone 
with  imbedded  libers ;  II.B,  Haversian-system  bone  without  fibers  built  around  the  medul- 
lary space,    (.\bout  200  X.) 

alveolus  is  like  the  solid  subperiosteal  bone,  and  is  penetrated 
throughout  its  thickness  by  the  imbedded  fibers ;  but,  as  with  the 
subperiosteal  bone,  it  is  constantly  being  penetrated  by  perforating 
canals,  the  solid  bone  being  removed  by  resorption  and  relniilt  in 
bone   with    Haversian    systems.     This    process    is    shown    in    Fig.  82, 


PERIDENTAL  MEMBRANE. 

FiC4.  84. 


107 


<f*'-    sg^"s^^^!='- 


Oe 

■B 

Oe 


Osteoclast  absorption  oi  buoe  over  permanent  tooth :   Oc,  osteoclasts ;  B,  bone  of  crypt  wall; 
F,  fibrous  tissue  of  follicle  wall;  ^-1,  ameloblasts.    (About  62  X.) 

Fio.  85. 


Osteoclasts:  Oc,  osteoclasts ;  £,  bone.    (About  66 X.) 


108 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


a  section  tliroiioh  ;i  (rrowing  portion  of"  tlie  proccf?.s  aronnd  a  por- 
niancnt  tooth.  A  higher  power  (Fig.  83)  shows  the  penetrating 
libers  and  the  formation  of  Haversian-system  bone  witliout  fillers,  in 
the  body  of  the  process. 

The  osteoclasts,  or  myeloplaques,  are  bone-destroying  cells  (Fig. 
84)  ;  they  act  not  only  u})on  bone,  but  also  upon  ceinentuni  and  dentin. 
They  are  oval  cells,  often  as  much  as  30  microns  in  diameter,  and  con- 
tain many  nuclei, — from  two  or  three  to  fifteen  or  twenty.  They  are 
often  called  giant  cells.  The  osteoclasts  are  not  constantly  found  in  the 
membrane,  but  make  their  appearance  whenever  calcified  tissues  are  to 
be  destroyed.  In  order  for  them  to  act  npon  the  tissues  they  must  lie 
in  contact  with  its  surface,  and  therefore  the  first  step  in  absorption  of 
the  peridental  membrane  is  the  cutting  off  of  the  fibers  imbedded  in 
the  bone  or  cementum.     Where   the  osteoclasts  act  upon  the  surface  of 


Fig.  86. 


Record  in  the  calcified  tissue  of  an  absorption  repaired  :  Z>,  dentin  ;  Cm,  cementum  filling  ubsorj)- 

tion  cavity.    (About  40  X.) 


the  tissue  they  produce  bay-like  excavations,  in  which  they  lie,  and 
which  are  known  as  Howship's  lacunae.  These  excavations  are  shown 
in  Fig.  87,  though  the  osteoclasts  have  disappeared.  In  Fig.  86, 
from  a  ground  section,  the  basin-like  excavations  are  shown  filled  with 
new-formed  cementum,  thus  leaving  in  the  tissue  the  record  of  an 
absorption  repaired.  In  absorption  of  the  roots  of  the  temporary  teeth 
the  osteoclasts  are  found  not  only  in  the  membrane  and  attacking  the 
surface  of  the  root,  but  all  through  the  medullary  spaces  in  the  bone, 
removing  the  temporary  alveolar  process. 

When  absorption  is  going  on  at  one  place  on  the  surface  of  a  root 
a  compensating  formation  of  cementum  is  going  on  at  another,  so 
that  not  all  of  the  fibers  of  the  membrane  are  cut  off.     This  is  illus- 


PERIDENTAL  MEMBRANE. 


109 


trated  by  sections  of  temporary  teeth  that  are  ready  to  be  shed  (Fig. 
87). 


Fig.  87. 


Root  of  a  temporary  incisor,  showing  absorption  and  rebuilding  of  cementum  (from  sheep) :  G,  gin- 
givus ;  D,  dentin ;  Cm,  cementum ;  Ah,  absorption  cavity,  showing  Howship's  lacunae ;  Cw},  new- 
formed  cementum.    (About  50  X.) 


EPITHELIAL,  STEUC?rUEES   OF   THE   MEMBRANE. 

The  peridental  membrane  contains  cellular  structures  of  epithelial 
character  which  are  so  conspicuous  that  they  demand  consideration, 
though  their  nature  and  origin  are  not  as  yet  fully  understood. 

These  structures  were  first  well  illustrated  and  described  by  Dr. 


110 


DENTAL  HISTOLOGY  AM)   OPERATIVE  DENTISTRY. 

Fi<;.  s«. 


Diagram  of  glani-    .i   I .      i:!,    :   .  nihrane.    (G.  V.  IJluck.) 
Fig.  89. 


Epithelial  structures  of  the  peridental  meinbiaiiu  (from  sheep):   Fb,  fibroblasts;  Ec,  epithelial 
structures;  Cb,  cementoblasts ;  On,  cementum;  D,  dentin.    (About  468  X.) 


PERIDENTAL  MEMBRANE. 


Ill 


Blacky  in  his  work  on  the  periosteum  and  peridental  membrane,  in  1887, 
and  were  called  by  him  the  glands  of  the  peridental  membrane.  About 
the  same  time  von  Brunn  ^  described  what  are  probably  the  same  struct- 
ures, and  which  he  regarded  as  embryonal  remains  of  the  inner  layer 
of  the  enamel  organ,  which  he  described  as  growing  down  over  the  sur- 
face of  the  root.     These  structures  appear  as  cords  of  epithelial  cells 

Fig.  90. 


Epithelial  structures  (from  sheep) :  Fb,  fibroblasts ;  Ec,  epithelial  structures ;  Cb,  eementoblasts ; 
Om,  cementum ;  X),  dentin.    (About  700  X.) 


arranged  in  the  form  of  a  network  winding  between  the  fibers  of  the 
membrane,  very  close  to  the  cementum  and  surrounding  the  root  almost  to 
the  apex.  Their  arrangement  is  illustrated  in  Fig.  88,  a  diagram  by  Dr. 
Black.  The  meshes  of  the  net  are  close  in  the  gingival  portion  of  the 
membrane,  but  grow  more  and  more  open  in  the  alveolar  portion.  They 
are  not  confined  to  the  membranes  of  young  teeth  or  the  temporary  den- 
tition, as  Dr.  Black  has  shown  them  in  the  membrane  of  a  tooth  from 
a  man  seventy  years  old,  though,  like  all  of  the  cellular  elements  of  the 

^  Archivf.  mikros.  Anat.,  1887. 


112 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


meinbrano,  they  hecome  less  nuinerous  as  age  advances.  These  struct- 
ures are  specially  well  shown  in  the  membranes  of  the  pig  and  sheep. 
Fig.  89  shows  their  ai)pearaiu'e  in  a  transverse  section  of  the  root  of  an 
incisor  of  a  sheep  ;  here  they  swing  out  from  the  surface  of  the  cemen- 
tum  and  hack  again  in  loops,  winding  in  and  out  among  the  fibers. 
Studied  with  higher  powers  (Fig.  90),  they  are  seen  to  be  made  up  of 
epitlielial  cells  with  large  oval  nuclei  which  react  to  the  characteristic 
epithelial  stains.  They  are  arranged  in  cords,  though  sometimes  what 
seems  to  be  a  lumen  of  a  gland  tubule  can  be  found  (Fig.  91).     The 


Fig.  91. 


Epithelial  structures:    Ec,  epithrlial   .       :.     j  i;irently  showing  a  lumen; 
Cin,  cementum  ;  U,  dentin.    (About  500  X.) 


cords  are  invested  with  a  delicate  basement  membrane,  but  no  special 
relation  to  bloodvessels  has  been  demonstrated.  The  attempt  to  show 
their  connection  with  the  surface  epithelium  has  thus  far  failed.  As  the 
gingivus  is  approached  (Fig.  92),  they  seem  to  swing  out  from  the  sur- 
face of  the  root  and  are  lost  between  the  projections  of  the  epithelium 
lining  the  gingival  space.  There  is  evidence  that  these  structures  are, 
at  least  in  some  cases,  of  importance  as  the  primary  seat  of  pathological 
conditions  of  the  membrane. 


PERIDENTAL  MEMBRANE. 

Fig.  92. 


113 


Longitudinal  section:  Ep,  epithelium  lining  the  gingival  space;  Gg,  gingival  gland,  so  called , 
D,  dentin  ;  N,  Nasmytli's  membrane  ;  Du,  duct-like  structure  stretching  away  toward  the  gin- 
givus  from  the  epithelial  cord,  seen  at  Ec ;  Cm,  cementum,  separated  from  the  dentin  by 
decalcification.    (About  50  X.) 

8 


114  DESTAL   IirSTOLOGY  AM)   OPERATIVE  DENTISTBY. 

Fin.  9X 


Fig.  94. 


Young  and  old  membranes  (from  sheep) :  D,  dentin  :  Cm,  cementum :  Cm\  thickening  of  cemtn- 
tum  to  attach  fibers  at  the  corner;  Fd,  peridental  membrane  ;  B,  bone  forming  the  wall  of  the 
alveolus;  y,  pulp.    (About  80  X.) 


PERIDENTAL   MEMBRANE.  115 

BLOODVESSELS    AND    NEEVES    OF   THE    MEMBRANE. 

Bloodvessels. — The  blood-supply  of  the  peridental  membrane  is 
very  abundant.  Several  vessels  enter  the  membrane  from  the  bone  in 
the  apical  region.  These  arteries  branch  and  divide,  forming  a  rich 
network,  from  which  the  capillary  vessels  are  given  oif.  The  arterial 
network  is  constantly  receiving  vessels  which  enter  the  membrane 
through  Haversian  canals  opening  on  the  wall  of  the  alveolus,  and  in 
this  way  the  size  of  the  vessels  passing  occlusally  is  maintained.  Ar- 
terial vessels  also  enter  the  membrane  over  the  border  of  the  process. 
This  double  or  triple  supply  of  the  membrane  is  important,  as  it  main- 
tains the  health  of  the  membrane  when  the  supply  entering  through 
the  apical  region  is  entirely  cut  off  by  alveolar  abscess.  While  the 
arterial  supply  of  the  membrane  is  very  rich,  the  capillaries  in  the 
membrane  are  comparatively  few.  This  is,  however,  a  characteristic 
of  connective-tissue  membranes. 

The  nerves  of  the  peridental  membrane  have  not  been  sufficiently 
studied  to  be  described  in  detail.  Six  to  eight  medullated  nerve  trunks 
enter  the  apical  region  in  company  with  the  bloodvessels,  and  they  re- 
ceive other  trunks  through  the  wall  of  the  alveolus  and  over  the  border 
of  the  process,  but  the  manner  of  their  distribution  and  the  nature  of 
their  endings  are  not  known. 

THE    CHANGES    WHICH  OCCUR    IN    THE    MEMBRANE   WITH    AGE. 

When  a  tooth  is  erupted  the  roof  of  the  bony  crypt  in  which  it  was 
inclosed  in  the  body  of  the  bone  is  removed  by  absorption  and  the 
crown  advances  through  the  opening.  The  diameter  of  the  alveolus  at 
that  time  is,  therefore,  greater  than  the  greatest  diameter  of  the  crown, 
and  the  peridental  membrane  which  fills  the  space  is  very  thick.  By 
the  formation  of  bone  on  the  wall  of  the  alveolus  and  the  formation 
of  cementum  on  the  surface  of  the  root  the  thickness  of  the  membrane 
is  reduced.  In  the  young  membrane  most  of  the  large  bloodvessels  are 
found  in  its  outer  half,  forming  a  rather  defined  vascular  layer  near  its 
centre.  In  the  old  membrane  most  of  the  bloodvessels  are  found  very 
close  to  the  surface  of  the  bone,  often  lying  in  grooves  in  its  surface. 
Both  young  and  old  membranes  are  illustrated  in  Figs.  138  and  139, 
which  are  taken  from  the  temporary  teeth  of  a  sheep,  one  just  after 
eruption  and  the  other  shortly  before  the  time  of  shedding. 


CHAPTER   III. 

ANTISEPSIS  IN  DENTISTRY. 
By  James  Teuman,  D.  D.  S. 


The  importance  of  antisepsis  in  dental  operations  has  not  been 
recognized  as  fully  as  the  subject  would  seem  to  warrant.  This  has 
been  in  part  due  to  the  fact  that  dentists  have  been  accustomed  to  the 
thought  that  cleanliness  in  the  use  of  instruments  would  meet  all  the 
requirements  of  practice.  This  idea  has  been  enforced  by  a  general  im- 
munity from  unpleasant  sequelae  after  operations,  thus  leading  to  a  skep- 
ticism in  regard  to  the  value  of  antiseptic  measures  in  the  oral  cavity. 
This  immunity  has  been  in  part  due  to  the  fact  that  the  fluids  of  the 
mouth  were  supposed  to  have  a  direct  influence  in  preventing  in- 
fection. This  has  never  been  proved  through  laboratory  experiments, 
but  clinical  observation  and  long  experience  have  demonstrated  that 
injuries  in  the  mouth  ordinarily  heal  rapidly,  even  though  these  be  made 
by  infected  instruments.  It  seems  unreasonable  to  suppose  that  a  fluid 
peculiarly  subject  to  fermentation  should  have  this  effect,  and  this  has 
led  some  to  ascribe  it  to  a  vital  influence.  Miller^  says  of  this  :  "It 
is  a  very  fortunate  provision  that  the  gums  in  a  healthy  state  offer  so 
powerful  a  resistance  to  the  invasion  of  the  germs  of  most  infectious  dis- 
eases. JFor  this  reason  a  wound  in  the  gums  may  be  followed  by 
scarcely  any  reaction  whatever,  while  a  similar  wound  on  the  hand 
with  the  same  instrument  may  produce  most  disastrous  results.  It  has 
been  attempted  to  account  for  this  fact  on  the  supposition  that  the 
saliva  has  an  antiseptic  action,  in  evidence  of  which  we  are  often  re- 
minded that  dogs  lick  their  wounds,  and  that  these  heal  rapidly. 
I  doubt  if  there  is  anyone  who  would  wish  us  to  believe  that 
the  dead  saliva  has  even  the  slightest  antiseptic  properties,  in  consid- 
eration of  the  fact  that  saliva,  especially  when  it  contains  much  organic 
matter,  readily  putrefies.  If  the  saliva  possesses  any  such  property,  it 
must  be  sought  for  in  its  living  histological  elements, —  i.  e.,  in  the  living 
leucocytes  or  phagocytes."  ^ 

^  Dental  Cosmos,  July,  1891. 

^  For  an  elaborate  study  of  this  problem  see  "  Experimental  Study  of  the  Different 
Modes  of  Protection  of  the  Oral  Cavity  Against  Pathogenic  Bacteria,"  by  Arthur  C. 
Hugenschmidt,  M.  D.,  Dental  Cosmos,  xxxviii.,  p.  797. 

117 


118  ANTISEPSIS  IN  DENTISTRY. 

While  it  is  true  that  there  exi.sts  a  degree  of  exemption  from  serious 
results,  leading  to  indiiferenee  and  careless  management  of  cases,  it  is 
equally  true  that  infection  has  resulted  in  the  experience  of  almost 
every  operator  in  dentistry. 

Prior  to  the  period  when  leister  announced  that  all  operations  in 
surgery  should  be  performed  antiseptically,  and  made  modern  surgery 
possible,  this  ignorance  was  excusable  ;  but  at  the  present  time,  with  the 
accumulated  knowledge  in  bacteriology,  it  should  be  impossible  for  any 
dental  operator  to  neglect  the  j)rocedures  under  this  head  considered 
absolutely  essential  for  the  general  surgeon. 

The  difficulties  attending  antisepsis  in  dentistry  far  exceed  those  in 
other  branches  of  surgery.  The  dentist  is  necessarily  obliged  to  meet 
conditions  hourly  that  seem  to  preclude  absolute  freedom  from  sources 
of  contamination.  If  he  were  to  take  the  same  precautionary  measures 
now  regarded  as  necessary  for  the  surgeon,  he  would  find  practice  almost 
impossible.  AYhile  this  is  true,  it  does  not  follow  that  every  effort 
should  not  be  made  to  approach  absolute  surgical  cleanliness. 

The  usual  methods  employed  to  accomplish  this,  while  valuable  to 
a  limited  extent,  are  by  no  means  equal  to  what  could  readily  be  secured 
without  consuming  much  time  or  patience.  The  dentist  is  usually  sat- 
isfied that  he  has  fulfilled  all  antiseptic  precautions  when  he  has  dipped 
his  instrument  in  some  antiseptic  fluid,  generally  carbolic  acid.  Little 
or  no  attention  is  paid  to  the  possibility  of  infection  from  rubber-dam, 
towels,  hands,  and  the  variety  of  instruments  that  enter  into  dental 
operations.  Some  of  the  latter,  as,  for  instance,  the  separator,  are  more 
liable  to  carry  infection  than  the  excavator,  the  one  generally  regarded 
as  most  important. 

The  appliances  ordinarily  in  daily  use  are  the  rubber-dam,  excava- 
tors, broaches,  pluggers,  clamps,  ligatures,  separators,  drills,  hand- 
pieces, napkins,  and  forceps.  It  is  safe  to  assume  that  but  few  of  these 
will  receive  any  attention  beyond  ordinary  washing.  The  rubber-dam 
is  too  often  used  as  it  is  furnished  by  the  manufacturer.  If  an  attempt 
at  cleanliness  is  made,  it  consists  in  washing  the  dam  in  cold  or  warm 
water,  this  being  regarded  as  sufficient.  When  it  is  remembered  that 
this  is  passed  between  teeth  and  usually  forced  up  under  gingival 
margins  with  ligatures,  or  clam])s,  frequently  lacerating  the  surface,  it 
becomes  evident  that  the  possibility  of  infection  is  always  present. 
If  infection  does  not  occur  from  the  rubber,  it  is  almost  certain  to  pro- 
duce a  wound  in  a  locality  extremely  favorable  for  the  growth  of  patho- 
genic germs.  The  result  is  innumerable  lesions  that  may  extend  to 
pericemental  inflammations.  The  great  increase  in  the  past  twenty- 
five  years  of  gingival  inflammations  subsequent  to  operations  in  mouths 
of  more  than  ordinary  health  must  be  partly  ascribed  to  this  cause. 


SOURCES  OF  INFECTION.  119 

Excavators  ordinarily  receive  the  most  attention,  and  yet,  when  their 
use  is  considered,  they  possibly  require  the  least.  It  is  rarely  necessary 
to  use  the  excavator  outside  of  a  cavity,  where  infection,  if  at  all  pos- 
sible, would  do  the  least  harm,  for  the  continual  washing  of  the  cavity, 
as  the  operator  proceeds,  reduces  the  danger  to  a  minimum.  Broaches, 
and  all  instruments  intended  to  enter  the  pulp  canals,  require  the  most 
careful  attention,  and  this  applies  with  equal  force  to  drills ;  yet  it  is 
feared  that  both  of  these,  loaded  though  they  are  with  septic  matter, 
receive  but  indifferent  care.  When  the  dangerous  possibilities  which 
may  result  from  this  negligence  are  considered,  it  becomes  a  serious  if 
not  a  criminal  offence.  The  difficulty  in  making  these  instruments  germ- 
free  and  in  keeping  them  from  becoming  contaminated  is  fully  appre- 
ciated ;  yet  the  effort  must  be  made,  and  it  is  not  a  difficult  procedure, 
nor  does  it  require  a  large  consumption  of  time — an  important  item  to 
the  dental  operator. 

Pluggers  cannot  be  regarded  as  a  source  of  infection.  They  are 
used  solely  in  connection  with  metal,  and  therefore  strict  cleanliness 
is  all  that  is  absolutely  required.  It  is  fortunate  that  this  is  so,  for 
these  instruments  require  unusual  care  to  protect  them  from  rust. 
Hence  immersion  in  an  antiseptic  fluid  is  deleterious  and  not  re- 
quired. 

Separators — and  under  this  head  are  included  metal  with  screw 
attachments  and  wedges — require  special  attention,  but  probably  receive 
the  least.  They  should  be  made  as  nearly  sterile  as  possible  before 
their  use  upon  a  patient. 

Hand-pieces,  of  the  various  kinds  in  use,  are  probably  the  most 
difficult  to  keep  thoroughly  clean.  While  they  do  not  come  in  direct 
contact  with  the  tissues  of  the  mouth,  they  may  indirectly,  by  contam- 
inating the  hands,  produce  unpleasant  results.  Frequent  taking  apart 
and  boiling  are  essential,  and  should  not  be  omitted. 

Napkins  from  the  ordinary  wash  have  been  and  are  used  with  con- 
fidence that  no  bad  results  from  use  can  follow.  If  the  laundry  is  con- 
fined to  the  home,  this  may  ordinarily  be  true,  but  the  indiscriminate 
mingling  of  washes  indulged  in  by  the  commercial  laundryman  is 
always  a  menace  to  health.  Where  napkins  of  the  latter  character  are 
to  be  used  they  should  be  subjected  to  the  sterilizing  process. 

The  chair  occupied  by  a  variety  of  patients  may  be  a  source  of 
disease,  and  should  be  carefully  cleansed,  especial  care  being  taken  with 
the  head-piece.  The  latter  should  be  covered  with  a  clean  napkin,  to 
be  changed  for  every  patient. 

The  cuspidor,  where  the  fountain  is  not  used,  is  ordinarily  an  abom- 
ination, for  here,  if  anywhere,  will  carelessness  be  manifest.  There  can 
be  no  excuse  for  this,  as  thorough  daily  scalding  with  boiling  water  and 


120 


ANTISEPSIS  IN  DENTISTRY. 


Fio.  95. 


the  use  of  antiseptics  will   keep  it   measurably   tree  from   unpleasant 

consequences. 

Glasses  require  to  be  tli()r()uii;lily  boiled 
both  before  and  after  use.  Jioiling  should 
never  be  neglected  with  ejector  tubes,  either 
metal  or  glass,  glass  being  generally  used. 
Hard  boiling  in  water  for  twenty  minutes 
should  be  sufficient. 

The  lancet  is  an  instrument  demanding 
especial  care,  as  it  may  become  a  danger- 
ous source  of  infection.  Before  it  is  used 
the  adjacent  portions  of  the  gum  should  be 
Mashed  with  an  antiseptic. 

The  forceps  employed  in  extraction 
should  be  so  constructed  as  to  render  the 
blades  readily  separable  at  the  joint,  and 
they  should  be  boiled  in  soda  bicarbonate 
solution  for  an  hour.  The  recorded  cases 
of  infection  from  these  instruments  render 
this  care  imperative  in  all  instances. 

Fig.  95  shows  a  convenient  form  of 
apparatus    for   sterilizing   ordinary    dental 


Downie  steam  steriliztr. 


instruments  by  boiling  soda  solution. 

Oral  Diseases  and  Their  Transmission. 

The  possibility  of  carrying  disease  from  one  person  to  another  seems  so 
self-evident  that  it  ought  not  to  require  more  than  a  word  of  caution, 
and  yet  it  is  clear  that  the  attention  given  to  this  source  of  danger  is  by 
no  means  commensurate  with  the  risks  assumed  constantly  in  practice. 
The  peculiarly  transitory  character  of  much  of  dental  practice  precludes 
the  possibility  of  any  previous  history  of  patients,  and  therefore  every 
one  should  be  regarded  as  a  possible  source  of  infection. 

Diseases  the  result  of  pathogenic  bacteria  independent  of  possible 
external  infection  are  now  in  the  main  well  understood,  but  by  no  means 
equally  appreciated  by  medical  practitioners,  nor  are  they  properly  con- 
sidered by  dental  operators.  Miller'  states  that  "many  facts  favor  the 
supposition  that  a  considerable  number  of  pathogenic  micro-organisms 
may  thrive  in  the  juieo'^  of  the  mouth  without  showing  in  their  vital 
manifestations  any  distinction  from  the  common  parasites  of  the  oral 
cavity  as  long  as  the  mucous  membrane  remains  intact.  If,  however, 
the  soft  tissues  have  been  wounded,  as  in  extraction,  or  if  the  resistance 
of  the  mucous  membrane  has  been  im])aired,  these  organisms  may  gain 
'  The  Micro-organisms  of  the  Human  Mouth,  page  275. 


OBAL  DISEASES  AND   THEIR   TRANSMISSION.  121 

a  point  of  entrance  and  thus  become  able  to  manifest  their  special 
actions."  This  fact,  now  well  recognized,  is  being  constantly  demon- 
strated in  the  use  of  the  various  appliances  that  may,  through  careless 
handling,  injure  the  mucous  membrane.  So  much  is  this  the  case  that 
a  large  proportion  of  gingival  inflammations  have  undoubtedly  had 
their  origin  from  this  cause.  It  has  come  under  the  observation  of  the 
writer  that  injuries  thus  received,  although  apparently  unnoticed  by 
dentist  or  patient,  have  resulted  in  the  course  of  forty-eight  hours  in 
very  disturbing  pericementitis,  confusing  to  the  operator  and  very  painful 
to  the  patient.  The  necessity  for  such  antiseptic  precautions  here  as  are 
taken  in  general  surgery  is  almost  entirely  overlooked.  Before  placing 
the  cofFer-dam,  the  clamp,  or  ligature,  that  portion  of  the  mouth  should 
be  thoroughly  washed  with  an  antiseptic  solution  and  an  effort  made 
to  render  the  appliances  equally  sterile,  or  at  least  to  inhibit  develop- 
ment for  a  definite  period.  When  the  operation  has  been  completed 
the  same  care  should  be  extended  to  the  tooth  and  contiguous  structures. 
The  evidence  is  abundant  that  many  cases  of  pyorrhea  alveolaris  have 
had  their  origin  from  this  careless  indifference  to  accepted  and  necessary 
precautions. 

The  mouth  as  a  source  of  disease  to  the  general  system  does  not 
properly  belong  to  this  article  to  discuss,  but  its  importance  cannot  be 
overlooked.  Dental  writers  have  devoted  much  attention  to  this  sub- 
ject. It  is  for  the  dentist  to  understand  that  he  is,  to  a  large  degree, 
responsible  for  the  general  health  of  his  patient  as  far  as  the  mouth  is 
concerned,  and  he  should  insist  on  prophylactic  measures  that  will  at 
least  reduce  this  source  of  disease  to  a  minimum.  The  constant  danger 
of  what  Miller  aptly  calls  "auto-infection"  from  the  collection  and 
propagation  of  pathogenic  bacteria  in  the  fluids  of  the  mouth  should 
suggest  to  the  dentist  constant  efforts  to  effect  the  removal  of  all  deposits 
on  the  enamel,  gingival  margins,  tongue,  and  mucous  membrane.  This 
line  of  study  will  bring  about  in  the  future  an  entirely  different  dentistry 
as  to  hygiene  and  prophylaxis  from  that  practised  at  the  present  time. 

The  pulp  of  a  tooth  is  not  ordinarily  regarded  as  a  point  of  in- 
fection, and  yet  it  is  well  known  to  be  a  serious  menace  to  the  health 
of  an  individual.  Israel,  quoted  by  Miller,^  asserts  that  "  the  root 
canal  furnishes  a  point  of  entrance  even  for  the  ray-fungus,  actinomyces, 
and  in  one  case  the  microscopic  examination  revealed  the  elements  of 
this  organism  in  the  canal  of  a  pulpless  tooth."  When  it  is  considered 
that  some  individuals  have  decomposed  pulps  in  a  number  of  teeth  at 
the  same  time,  and  frequently  a  score  of  dead  and  broken  roots,  sending 
out  their  infectious  material,  it  is  not  surprising  that  disease  of  a  serious 
nature  may  supervene.  While  there  is  no  record  of  cases  coming 
^  The  Micro-organisms  of  the  Human  Mouth,  p.  285. 


122  ANTISEPSIS  IN  DENTISTRY. 

within  the  observation  of  the  writer  of  pulps  produeing  pyemia  direetly, 
it  is  a  well-known  fact,  snpported  by  a  lonj^  list  of  recorded  cases, 
that  alveolar  abscess,  with  its  concentration  of  putrid  material,  is  liable 
to  be  followed  by  blood-poisoning. 

There  is  no  question  that  diseases  of  the  digestive  organs,  of  the 
lungs — in  fact,  of  all  the  organs  of  the  body — may  be  produced  by 
infected  material  germinated  in  the  mouth,  and  indeed,  through  sputum 
ejected,  may  attec-t  individuals  remotely  situated. 

Miller,'  in  considering  this  portion  of  the  subject,  says  :  "  We  know 
that  under  certain  circumstances  .saccharomycetes  may  directly  colonize 
in  the  mucfMis  membrane  of  the  mouth,  and  that  in  the  mouths  of 
enfeebled  individuals  bacteria  may  occasionally  obtain  a  foothold. 
The  mucous  membrane  of  the  mouth  and  pharynx  is  especially  sus- 
ceptible to  the  action  of  certain  germs  of  infection  (those  of  diphtheria, 
syphilis,  etc.),  and  large  portions  of  the  mucous  membrane  and  the  sub- 
mucous tissue  may  be  wholly  destroyed  by  parasitic  influences." 

There  is  a  phase  of  this  subject  that  requires  more  extended  in- 
vestigation. Inflammations  of  the  mouth  are  not  infrequent  where 
great  swelling  is  present.  This  may  be  observed  around  the  lower 
third  molars  with  no  explainable  cause  in  dead  pulps,  overlapping 
mucous  membrane,  retarded  eruption,  or  mal-presentation.  It  is  evi- 
dently produced  by  bacterial  invasion,  but  has  not  always  yielded  to 
antiseptic  measures,  and  at  times  has  resulted  in  abscess  entirely  inde- 
pendent of  pulp  devitalization. 

A  recent  report  of  three  cases  by  Dr.  John  A.  McClain  ^  in  the 
medical  practice  of  Dr.  M.  G.  Tull  is  interesting  as  indicating  possi- 
bilities. The  first  case  was  an  extensive  swelling  posterior  to  the  lower 
third  molar.  He  could  not  connect  it  with  that  tooth,  and  suspected 
auto-infection.  He  had  cultures  made  with  negative  results.  His 
theory  was  that  it  was  diphtheritic  ;  and,  although  laboratory  evidence 
was  wanting,  he  determined  to  inject  antitoxin.  This  injection  was 
followed  in  twenty-four  hours  by  an  entire  reduction  of  the  swelling. 
All  other  efforts  had  previously  failed  to  effect  any  result.  Two  other 
similar  cases  yielded  to  the  antitoxin  treatment  in  the  same  speedy 
manner.  If  this  can  be  regarded  as  something  more  than  a  coincidence 
in  practice,  it  may  lead  to  an  explanation  of  many  similar  anomalous 
pathological  cases  arising  posterior  to  the  third  inferior  molar,  yet 
apparently  not  connected  with  it.  Similar  conditions  have  been  the 
cause  of  much  uncertain  diagnosis  and  still  more  empirical  treatment. 

The  more  the  writer  has  considered  this  subject  the  more  important 
it  has  appeared ;  and  he  is  convinced  that,  when  the  proper  prophy- 

'  The  Micro-organisms  of  the  Human  Mouth,  p.  295. 
'■'  International  Dental  Journal,  October,  1900. 


INFECTION  FROM  MOUTH  TO  MOUTH.  123 

lactic  measures  come  into  use  for  the  prevention  of  tuberculosis,  in  all  its 
protean  forms,  antisepsis  of  the  mouth  will  be  given  primary  importance. 

Infection  from  Mouth  to  Mouth. 

Infection  from  mouth  to  mouth  through  instruments  is  a  difficult 
matter  to  prove  by  cases,  but  theoretically  there  can  be  no  cause  for 
disputation.  The  question  will  always  arise,  Was  the  lesion  occasioned 
by  auto-infection  or  by  transmission  ?  The  answer  can  rarely  be  given 
with  the  assurance  desirable.  In  one  instance,  at  least,  in  the  writer's 
experience  the  origin  was  clearly  traceable.  This  was  in  a  patient  of  the 
better  class,  presenting  for  treatment  in  the  clinic  of  the  Dental  Depart- 
ment of  the  University  of  Pennsylvania.  Her  teeth  were  remarkable  for 
structure,  regularity,  and  cleanliness  ;  gums  perfectly  healthy.  Necrosis 
of  the  anterior  alveolar  plate  was  threatened  when  first  seen,  and 
finally  resulted  in  the  entire  destruction  of  the  alveolar  border  and  all 
the  anterior  upper  teeth,  but  did  not  involve  the  maxilla.  The  history 
of  the  case  as  given  was  that  a  bicuspid  had  been  extracted  from  the 
right  superior  region  by  a  dentist  notorious  for  his  uncleanly  habits. 
Not  long  thereafter  the  patient  noticed  a  serious  inflammation.  These 
symptoms  indicated  a  syphilitic  infection,  and  the  family  physician  was 
consulted,  who  insisted  that  no  history  of  this  disease  existed  and  that 
infection  must  be  the  cause.  The  patient,  through  his  treatment  and 
that  given  locally,  recovered,  but  was  forced  to  wear  an  artificial  sub- 
stitute. 

Cases  of  infection  through  extraction,  either  by  the  forceps  or  after- 
infection  from  the  mouth,  might  be  quoted  almost  indefinitely.  Miller 
reports  case  upon  case — in  fact,  the  accumulation  of  these  has  become 
of  serious  moment ;  and  yet,  in  the  face  of  undisputed  facts,  dentists 
will  continue  to  extract  teeth  frequently  Avithout  any  precautions,  or, 
at  most,  relying  on  simple  washing  of  the  instrument.  Some  German 
writers  contend  that  antisepsis  after  extraction  is  wholly  unnecessary, 
as  the  clot  formed  is  a  sufficient  protection.  This  is  certainly  not  true 
in  all  cases.  It  is  not  always  the  fact  that  a  clot  is  formed,  or  when 
formed  that  it  serves  an  antiseptic  purpose.  One  of  the  most  serious 
cases  that  has  fallen  to  the  writer  to  treat  was  that  of  necrosis  of  the 
superior  maxilla  involving  destruction  of  the  right  side,  taking  in  all 
the  teeth  from  the  third  molar  to  the  lateral,  the  floor  of  the  antrum, 
a  portion  of  the  nasal  bones,  and  half  of  the  hard  palate.  This  was  the 
result  of  the  extraction  of  the  third  molar  by  a  specialist  before  the 
days  of  antisepsis;  whether  it  was  the  result  of  infection  is  difficult 
to  determine.  In  the  opinion  of  the  writer,  no  extraction  should  be 
attempted  until  the  instruments  used  have  been  thoroughly  sterilized  by 
boiling.     Before  the  forceps  are  applied  the  parts  surrounding  the  tooth 


124  ANTISEPSIS  IN  DENTISTRY. 

should  be  well  washed  with  an  aiitisoptio  solution.  After  the  extraction 
the  socket  should  be  syringed  with  sterilized  water,  followed  by 
some  powerful  disinfectant.  In  view  of  the  serious  results  j)rol)al>le  in 
this  operation  there  is  no  longer  any  excuse  for  injuries  resulting  from 
infection,  and  a  suit  for  malpractice  could  he  well  sustained  against  an 
individual  who  had  failed  to  observe  the  well-understood  methods  of 
antisepsis,  while  no  intelligent  practitioner  could  conscientiously  appear 
on  behalf  of  the  defendant. 

External  Infection. 

The  danger  to  the  operator  from  external  infection  from  instruments 
is  a  constant  menace ;  the  constant  use  of  these  with  general  freedom 
from  serious  results,  however,  leads  to  a  degree  of  carelessness  not  war- 
ranted by  the  ever-present  danger  from  wounds.  There  is  more  real 
danger  to  the  operator  from  this  source  than  to  the  patient.  All  the 
excavators,  drills,  and  broaches  are  hourly  in  contact  with  infectious 
matter,  and  it  requires  but  a  slight  wound  to  produce  any  of  the  possi- 
bilities of  blood-poisoning.  The  operator  should  be  on  constant  guard 
in  this  respect,  upon  the  slightest  abrasion  immediately  taking  measures 
to  destroy  all  possibility  of  infection  from  germs  that  may  have  been 
introduced  into  the  wound.  This  should  at  once  be  carefully  washed 
and  an  escharotie  employed,  burning  the  parts.  For  this  purpose  zinc 
chlorid  or  carbolic  acid  is  ])robably  the  best  agent  to  use,  followed  by 
an  antiseptic.  The  latter  should  be  frequently  renewed.  Experience 
has  demonstrated  the  value  of  turpentine  in  the  various  mechanical 
shops  where  this  agent  has  been  for  many  years  in  common  use  for 
wounds  from  rusted  iron,  the  possibility  of  trismus  resulting  from  such 
injuries  being  well  understood.  The  writer  has  used  this  agent,  after 
burning  the  wound,  almost  to  the  exclusion  of  other  antiseptics. 

An  illustration  of  the  ever-present  danger  from  wounds  occurred 
to  a  friend  of  the  writer's,  one  of  the  many  young  women  who  have 
graduated  in  dentistry  in  this  country.  She  accidentally  wounded  her 
hand  by  a  drill,  and  regarded  it  as  of  no  moment.  The  result  was  severe 
blood-poisoning  that  for  two  years  kept  her  hovering  between  life  and 
death.  After  suffering  from  severe  metastatic  abscesses,  she  was  finally 
restored  to  partial  health,  but  with  her  constitution  shattered  and  her 
practice  ruined  for  the  time  being. 

Implantation  and  Transplantation. 

Previous  to  the  recognition  of  the  importance  of  antisepsis,  the 
dentists  of  that  period  had  a  very  natural  objection  to  reimplanting 
teeth  ;  the  practice  of  transplantation  was  then  practically  an  unknown 
operation.     The  danger  of  the  operation  was  appreciated,  but  the  reason 


AGENTS   USED  FOR  STERILIZATION.  125 

was  not  then  comprehended.  When  the  study  of  bacteriology  had  ad- 
vanced to  a  science  through  the  labors  of  Pasteur,  Koch,  and  a  host  of 
investigators,  the  reasons  for  this  fear  were  explained,  and  the  condi- 
tions necessary  to  avoid  unpleasant  results  being  understood,  the  danger 
from  infection  was  changed  to  absolute  security.  It  is,  moreover,  to  be 
ever  borne  in  mind  that  but  for  this  knowledge  implantation  and  trans- 
plantation could  to-day  not  be  practised  without  the  probability  of 
serious  results. 

A  case  illustrating  this  point  occurred  prior  to  the  knowledge  of  anti- 
sepsis in  the  hands  of  a  well-known  dentist.  He  had  removed  three 
teeth  and  successfully  reimplanted  them  for  the  cure  of  a  violent  case  of 
neuralgia  presumably  due  to  calcific  depositions  in  the  pulp  and  about 
the  external  portions  of  the  roots.  Relief  was  so  immediate  that  upon 
return  of  the  pain  another  tooth  was  attempted.  Trismus  followed, 
resulting  in  the  death  of  the  patient.  It  is  safe  to  assume  that  this 
unfortunate  result  could  not  have  happened  under  the  antiseptic  care 
usual  at  the  present  time,  even  imperfect  as  it  frequently  is. 

To  accomplish  antisepsis  in  this  operation  the  greatest  care  is  neces- 
sary. In  transplantation,  teeth  being  procured  from  other  mouths, 
the  danger  is  necessarily  much  increased.  The  method,  adopted  by 
some,  of  immersing  these  teeth  in  various  antiseptic  fluids  cannot  be 
commended.  Miller  says  of  this  : '  "It  is  generally  accepted  that 
the  operator  takes  every  possible  precaution  when  he  allows  the  tooth 
to  lie  for  one-half  to  one  hour  in  a  1  per  cent,  solution  of  carbolic  acid, 
or  in  a  1  :1000  solution  of  bichloride  of  mercury.  ...  In  order  to 
reach  bacteria  that  may  have  penetrated  into  the  lacunae  or  chance  vas- 
cular canals  a  much  longer  action  of  the  antiseptic  is  necessary,  and  to 
be  perfectly  certain  that  we  have  accomplished  our  object  we  should 
have  recourse  to  boiling  water." 

Agents  used  for  Sterilization. 

The  possibility  of  injuring  instruments  has  deterred  dentists  from 
using  many  of  the  agents  recommended  for  the  purpose  of  sterilization. 

Miller^  made  tests  of  various  agents  with  indifferent  results,  with 
the  exception  of  carbolic  acid,  trichlorphenol,  and  mercury  bichlorid. 
The  list  tested  included  the  following : 

Carbolic  acid  in  5  per  cent  aqueous  solution  and  in  pure  form. 

Lysol  in  5  per  cent,  aqueous  solution. 

Trichlorphenol  in  5  per  cent,  aqueous  solution. 

Sublimate  in  5  per  cent,  aqueous  solution  ;  also  in  the  strength  of 
1  :  1000  of  water. 

Benzoic  acid  in  the  strength  of  1  :  300  of  water. 

^  Dental  Cosmos,  July,  1891.  ^  Ibid-,  page  520. 


126  ANTISEPSIS  IN  DENTISTRY. 

Potassium  pornian<i:anati'  in  5  per  cent,  aqueous  solution. 

Kesorcin  in  10  per  cent,  aqueous  solution. 

Hvclrogen  peroxid  in  10  per  cent,  aqueous  solution. 

Saccharin  in  concentrated  alcoholic  and  aqueous  solution. 

/3-naphthol  in  5  per  cent,  alcoholic  solution. 

Pvoktanin  in  concentrated  aqueous  solution. 

Absolute  alcohol. 

Antiseptin  in  5  per  cent,  aqueous  solution. 

Zinc  sulfate  in  concentrated  aqueous  solution. 

The  essential  oils  in  5  per  cent,  emulsions  and  in  pure  form. 

The  three  previously  named,  carbolic  acid,  trichlorphenol,  and 
mercury  bichlorid,  were  the  only  ones  that  gave  any  satisfactory 
results,  and  these  only  partially  so.  In  regard  to  the  rest.  Prof.  Miller 
says  :  "  They  all  fall  far  short  of  those  already  mentioned.  The  10  per 
cent,  solution  of  the  peroxid  of  hydrogen  came  next  to  carbolic  acid, 
but  is  considerably  inferior  to  it.  The  essential  oils,  in  emulsions  as 
well  as  in  pure  form,  utterly  failed  to  produce  the  desired  action." 

The  results  obtained  by  Miller  are  not  wholly  in  accord  with  those 
of  some  others.  Charles  B.  Nancrede,  M.  D.,  in  an  article  ^  gives  a 
list  of  agents  which  have  "  proved  most  reliable  clinically,  can  be  resorted 
to  in  any  emergency,  or  are  peculiarly  applicable  to  meet  exceptional 
indications : " 

Marked  Inhibition.       Complete  Inhibition. 

Mercuric  chlorid 1:1,000,000  1:300,000 

Oil  of  mustard 1 :  333,000  1  :  33,000 

Thymol 1:86,000 

Oil  of  turpentine 1:75,000 

lodin 1:5,000  1:  1,000 

Salicylic  acid 1:3,300  1:1,500 

Eucalyptol 1:2,500  1:1,251 

Borax 1  : 2,000  1 :  700 

Potas.  permanganate 1  :  1,400 

Boric  acid      1:1,250  1:800 

Carbolic  acid 1:1,250  1:850 

Qninin 1  :  830  1:625 

Alcohol 1  :  100  1  :  12.5 

At  the  time  these  tables  were  prepared  one  agent  not  mentioned  was 
practically  unknown  as  an  antiseptic, — formaldehyd,  or  in  solution 
known  as  formalin. 

Dr.  Elmer  G.  Horton,  B.  S.,  assistant  in  bacteriology,  Department 
of  Hygiene,  University  of  Pennsylvania,  undertook,  at  the  request  of 
Dr.  Edward  C  Kirk,  a  series  of  investigations  with  formaldehyd,^  the 
results  of  which  are  given,  omitting  the  details  of  experiments  : 

'  "Treatment  of  Wounds:  Antisepsis  and  Asepsis,"  Surgery  by  American  Authors, 
Park,  page  365. 

"  Dental  Cosmos,  July,  1898. 


AGENTS   USED  FOR  STERILIZATION. 


127 


"  We  employed  the  gas  generated  by  heating  over  an  alcohol  lamp 
a  pastil  which  contained  five  grains  of  paraform.  The  lamp  was  placed 
in  a  tin  box  of  nearly  one  cubic  foot  capacity  .  .  .  (Fig.  96).  Among 
the  instruments  employed  in  the  tests  were  various  chisels,  excavators, 
and  burs.  These  were  boiled,  shown  by  cultural  method  to  be  sterile, 
then  either  dipped  into  bouillon  cultures  or  infected  from  selected  cases 
found  in  the  operative  clinic  of  the  Department  of  Dentistry,  University 
of  Pennsylvania.  After  infection  each  instrument  was  placed  in  a  sterile 
tube  and  kept  at  incubator  temperature  (37.5°  C.)  for  three  hours.  .  .  . 
In  a  single  test  with  moist  instruments  we  found  sterilization  complete. 
After  the  infection  and  subsequent  drying  the  tubes  containing  the  in^ 
fected  instruments  were  separated  into  two  lots,  one  to  be  subjected  to 

Fifi.  96. 


Schering's  formalin  sterilizer. 


the  method  of  disinfection  and  the  others  to  be  kept  as  controls,  by 
which  would  be  shown  that  no  step  other  than  the  action  of  formalde- 
hyd  destroyed  the  vitality  of  the  germs.  .  .  .  After  exactly  ten  or 
fifteen  minutes,  according  to  the  experiment,  the  door  was  opened  and 
the  instrument  quickly  removed.  .  .  .  Each  instrument  (controls  like- 
wise) was  placed  in  a  considerable  amount  of  sterile  bouillon  and  these 
cultures,  together  with  the  subcultures  made  from  them,  observed  for 
at  least  one  week.  ...  In  all  experiments  a  free  growth  developed 
from  the  controls.  .  .  .  The  disinfection  of  instruments  purposely  in- 
fected in  the  clinics  from  cases  of  caries,  pyorrhea,  and  gingivitis  was 
satisfactorily  accomplished  in  every  case.  .  .  .  We  conclude  that  infected 
dental  instruments  can  be  disinfected  without  injury  in  a  closed  space 
of  less  than  one  cubic  foot,  by  an  exposure  of  fifteen   minutes   to  the 


128  ANTISEPSIS  IN  DENTISTRY. 

fornialdehyd  gas  generated  from  a  pastil  c'ontaining  five  grains  of  para- 
form  by  lieating  the  pastil  over  a  proper  alcohol  lamp." 

In  an  article  on  the  "  Uses  and  Limitations  of  Formaklehyd  in 
Dentistry,"  by  Dr.  F.  W.  Low,  Bnffalo,  N.  Y./  the  effect  of  formal- 
dehyd  gas  is  farther  given  as  shown  by  a  series  of  experiments  con- 
ducted by  Dr.  Thos.  B.  Carpenter,  assistant  bacteriologist  to  the  Health 
Department  of  the  City  of  Buffalo.  Without  entering  into  detail,  the 
experiments  consisted  of  two  series,  one  of  infected  instruments  and  the 
other  of  clothing  either  of  school-children,  of  nurses,  or  of  the  doctor 
in  the  presence  of  contagion,  to  determine  whether  they  could  be  thor- 
oughly sterilized  by  placing  them  over  night  in  a  wardrobe  exposed  to 
the  fumigation  of  the  lamp  used. 

The  conclusion  of  Dr.  Carpenter  was  that  "This  apparatus  can  be 
relied  upon,  after  an  exposure  of  from  ten  to  fifteen  minutes,  to  destroy 
thin  layers  of  the  common,   non-sporulating  pathogenic  organisms." 

In  regard  to  the  second  series  of  experiments  with  clothing,  he  says  : 
"  It  is  evident,  therefore,  that  twelve  hours'  exposure  to  the  action  of 
this  lamp  in  a  closet  of  15.8  cubic  feet  capacity  is  sufficient  for  effec- 
tive surface  disinfection,  the  most  resistant  pathogenic  bacteria  being 
destroyed." 

A  third  series  of  experiments  was  undertaken  with  scaling  instru- 
ments taken  from  the  instrument-cases  from  several  operators,  including 
that  of  Dr.  Low.  The  result  of  this  elaborate  experimentation  is  thus 
summed  up  by  the  author  :  "  Every  set,  excejit  the  one  ivhere  the  whole 
case  was  fumigated  over  night,  produced  some  cultures;  but  not  one  set 
developed  a  culture  of  pathogenic  organisms." 

"The  Low  lamp  consists  of  an  asbestos-lined  tray,  or  box,  sup- 
ported on  legs  {a),  with  an  opening  in  the  bottom  to  admit  the  chim- 
ney of  the  lamp,  the  purpose  of  which  is  to  conduct  the  fumes  of  the 
formaklehyd  gas  into  the  tray  and  upon  the  instruments  it  is  desired 
to  sterilize. 

"The  working  parts  of  the  lamp  are  shown  in  the  illustration.  An 
ordinary  alcohol  wick  is  drawn  into  the  M'ick  tube.  To  place  the  lamp 
[B)  in  operation  fill  it  with  wood  alcohol,  grain  alcohol  being  incapable 
of  generating  formaklehyd.  Adjust  cone-shaped  platinum  coil  so 
that  it  just  touches  the  top  of  the  wick.  Light  the  latter;  place  on 
chimney,  and  after  a  few  seconds'  waiting  blow  out  the  flame.  If  the 
cone  be  in  proper  adjustment  to  the  wick,  it  will  be  observed  that  the 
coil  glows  like  a  live  coal,  but  there  is  no  flame  or  dangerous  heat. 

"Having  the  lamp  in  operation,  as  described,  and  the  tray  properly 
adjusted  to  set  over  it,  as  in  illustration,  instruments  may  be  placed 
in  the  tray  and  allowed  to  remain  for  ten  minutes,  a  sufficient  time  to 
^  Dental  Cosmos,  February,  1900. 


AGENTS   USED  FOB  STERILIZATION. 


12& 


effect  sterilization.     When  taken  out  they  should  be  wiped  dry  with  a 
surgically  clean  napkin  or  towel. 

"To  stop  the  fumigation  going  on  in  the  lamp,  remove  the  chimney 
and  slide  the  cage  high  up  on  the  tube,  so  that  the  platinum  cone  no 
longer  touches  the  wick,  then  allow  it  to  cool  before  replacing  chimney." 

Fig.  97. 


Low's  formaldehyd  lamp :  A,  for  dental  use ;  B,  for  household  use  ;  C,  locked  cage  for  public  places. 

While  it  is  not  difficult  for  the  average  dentist  to  use  formaldehyd 
as  a  disinfectant,  it  will  probably  be  considered  a  useless  expenditure 
of  time,  and,  therefore,  boiling  in  water  and  soda  for  at  least  twenty 
minutes  seems  the  more  feasible  and  is  equally  certain  in  the  results. 

The  dentist  who  aims  to  keep  only  aseptic  instruments  should  have 
9 


l;30  ANTISEPSIS  JN  DENTISTRY. 

two  sets  in  daily  use  AVlicn  througli  with  one  patient  the  instruments 
should  undergo  the  boiling  process  in  preparation  for  the  next.  At 
the  close  of  the  day  all  instnniients  used  should  be  thoroughly 
boiled  and  dried  uj)on  aseptic  napkins  and  placed  in  the  case.  The 
possibility  of  infection  from  the  latter  must  not  be  overlooked.  The 
first  and  second  set,  therefore,  used  the  next  day  for  the  first  time  should 
be  either  boiled  again  or  each  instrument  dipped  into  an  antiseptic  fluid. 
For  this  purjiose  the  writer  prefers  a  strong  solution  of  hydronaplithol 
(8  grains  to  the  ounce  of  alcohol)  to  the  carbolic-acid  solution  ordinarily 
used.  With  this  care  all  danger  of  infection  can  be  removed  and  the 
dentist  relieved  of  all  legal  responsil)ility.  Tlie  combination  sterilizer 
and  hot-water  heater  for  gas  or  alcohol,  designed  l)y  J)r.  (Jeorge  J. 
Pavnter,  seems  to  be  a  convenient  arrangement  for  the  office. 

The  preparation  of  the  hands  previous  to  operations  is  most  per- 
plexing to  the  conscientious  operator,  whether  this  be  in  surgery  or 
dental  practice.  In  order  that  dental  operators  may  be  al)le  to  arrive 
at  definite  conclusions  in  regard  to  what  may  be  required  of  them  in 
their  daily  work,  the  following  quotation  is  given  from  Xancrede's 
article  '  on  the  care  required  in  hospital  surgical  practice  : 

"  Sterilized  water  as  hot  as  can  be  borne  should  be  employed.  This 
must,  of  course,  be  never  cooled  by  the  addition  of  any  but  cold  ster- 
ilized water.  .  .  .  The  nail-brush,  best  made  of  vegetable  fiber,  must 
be  always  carefully  rinsed  after  use  and  sterilized  by  heat  for  each 
operation,  ,  ,  ,  Although  it  is  alleged  that  all  soajjs  made  l)y  heat  are 
sterile — indeed,  that  potash  soap  is  an  active  germ-inhibitor  in  the  pro- 
portion of  1  :  5000 — yet  it  is  the  part  of  prudence  to  combine  with  the 
soft  soap  5  per  cent,  of  hydronaphthol  or  thymol,  to  insure  that  the 
soap  itself  is  free  from  germs.  After  thoroughly  rubbing  into  the  hands 
and  arms  and  under  the  nails  abundance  of  soap,  the  nail-brush  and 
hot  water  must  be  vigorously  used,  especially  beneath  and  around  the 
nails,  for  from  two  to  five  minutej.  Next,  carefully  clean  the  nails  and 
around  them  with  a  nail-cleaner.  Removal  of  all  grease  can  now  be 
effected  by  ether  or  by  immersion  in  alcohol,  or  best  by  alcohol  contain- 
ing 5  per  cent,  of  dilute  acetic  acid,  which  should  be  rinsed  off  thor- 
oughly with  sterilized  water,  removing  the  last  traces  of  soap.  Finally, 
the  hands  should  be  immersed — not  merely  dipped — in  a  1  :  2000  mer- 
curic chlorid  solution  for  not  less  than  three — preferal>ly  five — minutes. 
Instead  of  corrosive  sublimate  solution,  ordinary  mustard  flour  mixed 
in  the  hands  into  a  thin  paste  with  sterilized  water,  used  with  gentle 
friction  for  two  or  three  minutes  and  then  removed  with  sterilized 
water,  will  prove  a  most  successful  germicide." 

While  the  foregoing  may  serve  as  a  basis  for  comparison,  it    would 

'  Loc.  cil. 


AGENTS   USED  FOR  STERILIZATION.  131 

be  wholly  impracticable  in  dental  practice.  It  remains,  however,  that 
the  hands  of  the  dental  operator  should  be  the  subject  of  constant  care. 
Nails  should  be  kept  short  and  scrupulously  clean.  It  seems  to  the 
writer  that  the  use  of  a  good  potash  soap  and  nail-brush,  with  bathing  the 
hands  in  alcohol,  will  be  amply  sufficient  unless  working  on  a  syphilitic 
patient,  when  more  effective  methods  must  be  resorted  to,  and  there  can 
be  nothing  better  than  the  mode  described  by  Dr.  Nancrede. 

The  conclusions  to  which  the  writer  has  arrived  from  experience  and 
study  of  the  subject  may  be  summed  up  briefly  as  follows  : 

1.  Dipping  instruments  in  an  antiseptic  fluid  previous  to  operating, 
while  beneficial,  is  not  sterilization. 

2.  That  boiling  with  soda  is  for  the  dentist  the  most  convenient 
means  of  sterilizing  instruments  without  injury,  w^hile  the  more  recently 
introduced  method  of  formaldehyd  antisepsis  is  a  dry  process  that  does 
not  rust  or  injure  steel  instruments  and  is  also  promptly  effective. 

3.  That  the  ordinary  methods  used  to  effect  sterilization  in  surgical 
practice  are  not  possible  in  dentistry,  but  that  every  dentist  is  legally 
and  morally  bound  to  live  as  near  to  the  rules  of  antisepsis  as  is  possi- 
ble with  the  demands  of  a  daily  practice. 


CHAPTER   lY. 

THE  EXAMINATION  OF  TEETH  PRELIMINARY  TO  OPERA- 
TION—METHODS, INSTRUMENTS,  APPLIANCES— RECORD- 
ING RESULTS,  ETC. 

By  Louis  Jack,  D.  D.  S. 


The  Operator. 

The  attitude  of  the  body  of  the  dental  operator  has  considerable 
influence  upon  the  ease  with  which  the  various  positions  required  in 
operating  may  be  assumed,  and  also  has  some  bearing  upon  the  free- 
dom of  his  hands. 

The  erect  position  should  be  maintained  as  far  as  possible  and  the 
preponderance  of  the  weight  should  be  sustained  upon  the  balls  of  the 
feet.  This  secures  equilibrium  and  enables  movements  to  be  made 
with  little  embarrassment.  The  shoulders  should  be  held  well  back  in 
order  that  the  arms  may  not  be  cramped,  and  to  permit  the  respira- 
tion to  be  carried  on  deeply  and  with  quietness.  For  obvious  reasons 
the  breathing  should  be  deep,  slow,  and  always  through  the  nose. 

The  precise  use  of  the  fingers  requires  that  in  each  application  of  the 
instrument  a  7-est,  as  a  fulcrum  or  base  of  action,  should  be  used,  and 
when  force  is  to  be  applied  a  guard  in  addition  is  necessary  to  give 
security  to  the  movement  of  the  hand.  The  positions  of  the  rest  and 
the  nature  of  the  guard  required  in  operating  are  various,  depend- 
ing upon  the  situation  of  the  territory  of  operation  and  somewhat 
upon  the  natural  tact  of  the  individual,  so  that  a  definition  of 
them  is  scarcely  required.  Upon  a  careful  application  of  the  rests 
and  guards  depends  the  graceful  and  comfortable  use  of  the  instru- 
ments, and  by  means  of  them  the  hand  passes  by  quick  and  easy  grada- 
tion from  the  most  delicate  touch  to  the  safe  exhibition  of  considerable 
force.  Each  student  should  study  and  practice  the  use  of  the  various 
rests  and  guards  until  by  repetition  their  employment  becomes  invol- 
untary and  appropriate  to  the  situation.^ 

The  contact  with  the  patient  should  be  at  as  few  points  as  possible 
and  should  be  generally  made  with  the  fingers. 

Examination  of  the  teeth  and  mouth  in  all  their  particulars  is  a 

^  To  aid  in  this  study  see  American  System  of  Dentistry,  vol.  ii.  p.  44  et  seq. 

133 


134  EXAMINATION  OF  TEETH. 

necessary  preliiuinarv  to  the  treatiuent  of  any  diseased  or  distnrbed  condi- 
tion which  may  appear.  The  importance  of  this  procedure  cannot  be 
overestimated,  as  on  it  depends  the  formation  of  a  correct  diagnosis 
of  departures  from  the  normal  state  and  it  becomes  a  basis  for  the 
formulation  of  plans  for  the  treatment  re(piired  to  restore  the  teeth  and 
the  related  structures  to  a  state  of  health,  as  well  as  to  define  the  order 
in  which  the  several  ojicrations  shall  l>e  taken  up,  since  an  orderly  prr- 
vedeiur  in  the  treatment  of  individual  teeth  is  frequently  necessary. 

It  is  essential  that  the  examination  be  most  thorough,  to  prevent  any 
failure  to  notice  the  least  defect;  since  an  unoliserved  slight  lesion  may 
become  a  deeper  injury  in  a  few  months,  and  the  consequences  of  an 
oversight  may  prove  serious. 

Appliances  used  in  Examination. 

The  appliances  required  to  effect  thorough  observation  of  every 
portion  of  each  tooth  to  ascertain  the  extent  of  any  lesion  are  of  several 
kinds,  viz.  mirrors,  magnifying  glasses,  explorers,  floss  silk,  and  wedges. 

The  mirrors  should  be  both  plane  and  concave.  The  j)lane  mirror 
is  important  as  a  means  to  assist  by  the  reflected  image  in  determining 
the  position  of  defects  ;  the  concave  as  an  adjunct  to  effect  illumination, 
as  it  concentrates  the  rays  of  light  and  also  may  be  used  to  produce  an 
enlarged  image.  The  enlarged  image,  however,  is  less  sharp  in  defini- 
tion than  the  image  of  the  plane  mirror. 

Working  to  flic  Iinar/c. — The  plane  mirror  is  an  important  adjunct  in 
all  operative  procedures  connected  with  the  teeth.  Many  situations  in 
the  mouth  do  not  permit  the  direct  reflection  of  the  rays  of  light  to  the 
eye  without  assuming  positions  of  the  bo(l\  and  of  the  head  of  the 
operator  which  arc  awkward  and  embarrassing  to  iVec  movement  of  the 
hand,  as  well  as  necessitating  inconvenient  and  tiresome  positions  of  the 
head  of  the  patient.  In  addition,  it  frequently  is  impossible  to  secure 
correct  observation  of  the  progress  of  various  procedures  by  direct 
vision.  These  difficulties  may  be  overcome  by  the  movements  of 
the  hand  being  directed  by  the  image  of  the  field  of  the  pro- 
cedure on  the  mirror.  This  method  of  working  to  the  image  is  at  first 
difficult  to  the  novice,  since  the  images  are  reversed  ;  but  by  continued 
effort  it  becomes  as  easy  to  make  correct  a|)plication  of  movements  by 
this  method  as  l)y  the  direct  rays  of  light.  Further  continued  ])ractice 
in  this  way  renders  the  movements  so  completely  under  reflex  control 
that  the  operator  passes  from  a  direct  movement  to  a  reverse  one,  and 
the  contrary,  without  an  apparent  effort  of  the  brain.  This  is  equally 
true  in  all  the  various  movements,  even  of  those  where  the  employment 
of  considerable  force  is  required. 


APPLIANCES   USED  IN  EXAMINATION. 


135 


Fig.  99. 


The  Quality  of  the  Uirror. — These  appliances  should  constantly  be 
in  good  condition  to  insure  clear  definition  in  the  image.  The  best 
kind  of  glasses  are  those  in  which  the  surface  is  covered  by  a  deposit  of 

pure  silver.     This  furnishes  a  better  reflect- 
ing surface  and  is  more  durable  than  is  the 

so-called  "  silvering  "  with  tin  and 

Fig.  101. 
mercury. 

Magn;[fying  lenses  of  about  V^ 

four  diameters  are  useful  to  de- 
tect minute  defects  either  in  the 
teeth  or  in  the  condition  of  pre- 
vious operations  upon  the  teeth. 
They  are  used  either  directly  to 
magnify  the  parts,  or  else  to  mag- 
nify the  image  shown  on  the  face 
of  the  plane  mirror  when  direct 
rays  of  light  cannot  be  caught. 
The  latter  method  gives  a  clearer 
definition  than  the  magnified  image 
of  the  concave  mirror. 

The  magnifying  glass  may  be 

the    ordinary    watchmaker's    glass 

held  before  the  eye  by  the  muscles 

of  the  brow  and  cheek     ^     ,^^ 

Fig.  100. 
or    the    lens    mounted       -, 

as  shown  in  Fig.  144.  / 

Such  glasses  are  indis- 
pensable to  the  careful 
practitioner,  since  with 
their  aid  defects  of  the 
teeth  and  of  operations 
may  be  detected  which 
would  escape  obser- 
vation by  other  means. 
Explorers  are,  es- 
sentially, prolongations 
of  the  fingers ;  they 
convey  impressions  by 
their  vibrations  to  the  Explorer. 
tactile  nerves,  and  are  principally  intended  to  be 
applied  to  parts  where  direct  rays  of  light  cannot  reach.  The  forms 
required  are  simple  and  few.  Their  points  should  be  delicate,  to  enable 
the  smaller  apertures  and  spaces  to  be  entered,  and  are  best  when  made 


Magnifying  lens. 


Self-contained 
socket. 


136 


EXAMINATION  OF  TEETH. 


of  j>ian(»-\vir(',  Xo.  IS  B.  &  S.  gatitre,  filed  to  acuteness 
ami  bent  to  a  shape  similar  to  that  shown  in  Fig.  100. 
This  form  may  be  apj)lie(l  to  all  surfaces  of  the  teeth, 
and  but  slight  modifications  are  needed  to  explore  posi- 
tions difficult  of  direct  approach.  At  part  a  the  size  of 
the  finer  ones  should  be  No.  25,  and  near  the  ultimate 
point,  h,  No.  30.  The  temper  of  this  kind  of  steel  gives 
sufficient  stiffness  ayd  also  permits  slight  bending  to  make 
modifications  of  the  form  to  meet  all  requirements.  The 
ultimate  jioint  may  be  sharpened  and  renewed  at  pleasure. 
The  handles  in  which  these  instruments  are  inserted  may 
be  of  wood,  with  metal  sockets  which  should  be  of  sufficient 
length  to  come  into  contact  with  the  finger  ;  or  they  may 
be  fixed  in  metal  holders,  in  Avhich  case  the  latter  should 
be  tapered  to  avoid  weight  and  to  give  balance.  Either 
form  of  handle  should  be  round,  to  permit  fractional 
rotary  change  of  direction.  Fig.  145  shows  an  explorer, 
which  consists  of  a  socket,  into  which  the  wire  point  is 
secured  by  means  of  powd(>rcd  shellac  or  powdered  sidfur. 
The  points  may  be  displaced  and  renewed  when  required. 
This  socket  fits  into  the  usual  cone-socket  handles.  Fig. 
101  is  a  self-contained  socket  for  the  same  purpose.  These 
points  may  also  be  connected  with  broach  holders  that  have 
a  clutch  actuated  by  a  screw  nut. 

Explorers  of  this  kind  may  be  re-formed  by  straighten- 
ing and  then  re-dressing  between  two  emery-cloth  disks  in 
the  dental  engine,  when  the  ])oints  can  be  shaped  at  will. 

Floss  rilk  is  used  to  pass  between  the  approximal 
surfaces  of  the  teeth  at  the  places  which  are  in  too  close 
contact  to  permit  the  ingress  of  fine  explorers.  In  these 
positions  floss  silk  may  detect  the  presence  of  superficial 
softening  of  the  enamel  by  the  character  of  the  friction 
or  by  the  fraying  of  its  fibers.  It 
also  is  of  use  in  determining  the  con- 
dition of  fillings  on  approximal  faces 
or  the  presence  of  a  deposit  of  sali- 
vary calculus  at  similar  jwrts.     The 


Dow  electric  lamp  for  nii/iuli  illnniinjitiiiii  w  it'.:  nllcctdis.    Reflector  .4  is  jointer!  to  vary  the  angle 
of  retiection.  Reflector  B  is  for  illuniin;itiiin  (ft  lie  fauces.  Reflector  C'is  for  lateral  illumination. 


THE  EXAMINATION.  137 

silk  should  be  slightly  waxed  in  order  to  bind  the  fibers.  Entire 
reliance  cannot  be  placed  upon  the  use  of  silk,  since  it  may  in  some 
cases  pass  slightly  carious  spots  without  the  fibers  being  displaced,  but 
it  frequently  furnishes  indications  for  further  procedures  by  which  to 
establish  certainty  as  to  the  state  of  approximal  surfaces. 

Wedges  are  used  when  neither  explorers  nor  silk  give  positive  indi- 
cations of  carious  action  but  have  raised  doubts  of  the  integrity  of  any 
part.  They  may  be  of  wood  where  the  teeth  are  not  firmly  fixed,  when 
the  space  may  be  immediately  made ;  otherwise,  where  the  fixation  is 
firm,  thin  india-rubber  or  linen  tape  may  be  forced  in. 

Transillumination  of  the  teeth  by  the  electric  mouth  lamp  (Fig.  102) 
is  extremely  useful  in  cases  where  a  question  has  arisen  as  to  the  condi- 
tion of  an  approximal  surface.  ■  Superficial  changes  of  the  enamel  may 
frequently  be  detected  by  this  means,  and  it  is  particularly  useful  in  deter- 
mining the  condition  of  approximal  surfaces  at  the  margin  of  the  gums. 
It  is  also  of  service  in  testing  the  vitality  of  the  pulp. 

The  Examination. 

The  parts  of  the  teeth  most  liable  to  carious  action  are  those 
which  most  easily  retain  deposits  of  sedimentary  matter  composed  of 
food  debris,  thickened  mucus,  and  bacterial  growths.  These  are  the 
labial  and  buccal  surfaces,  where,  the  mechanical  relations  of  the  lips 
and  cheeks  tend  to  retain  sediment ;  the  sulci,  which  by  the  direct 
force  of  mastication  have  food  driven  into  them  ;  and  the  opj^rox- 
imal  surfaces.  The  latter  are  the  most  important  to  consider. 
The  interproximal  space  is  a  serious  predisposing  cause  of  caries,  be- 
cause the  counteraction  of  the  tongue  and  cheek  in  adapting  the  food 
between  the  occlusal  surfaces  of  the  teeth  forces  the  finer  particles  of 
the  food  into  the  interproximal  spaces,  where  it  is  retained  by  capillary 
attraction,  assisted  by  the  viscidity  of  these  deposits,  and  by  the  apposi- 
tion of  the  cheeks  with  the  buccal  surfaces  of  the  teeth.  This  space  is 
usually  triangular,  the  gum  forming  the  base  of  the  triangle.  The  point 
where  caries  usually  begins  is  at  the  apex  of  this  triangle,  where  there 
is  the  least  movement  and  interchange  of  the.  contents  of  the  space,  as 
here  the  capillary  force  is  the  greatest,  so  that  the  fermentative  processes 
of  food  decomposition  are  least  interfered  with. 

The  technique  of  examination  is  as  follows :  After  a  cursory  in- 
spection of  the  denture  with  the  mirror,  the  explorer  is  applied  to  the 
previously  indicated  surfaces,  particular  care  being  used  in  determining 
the  condition  of  approxirtial  surfaces,  by  introducing  the  instrument 
into  the  triangular  space,  the  point  being  directed  toward  the  acute 
angle.  It  should  be  drawn  back  and  forth  with  a  slight  rotary  move- 
ment so  as  to  impinge  the  point  successively  upon  the  whole  approxi- 


188  EXAMINATION  OF  TEETH. 

nial  surface  of  each  tooth.  This  movement  should  be  made  from  the 
inner  as  well  as  from  the  outer  aspect.  In  this  manner  the  instrument 
will  he  hrou«»;ht  into  eontaet  with  everv  accessible  jiortion  of  the  inter- 
proximal surfaces. 

Then  the  .sw/Av'  are  explored  and  the  hnnnil  and  livf/nal  fiiirfaces 
examined. 

The  inspection  is  thus  conducted  from  tooth  to  tootii.  Next  the  lines 
of  apparent  contact  are  critically  tested  with  the  mirror  for  evidence  of 
slow  ehanu^es  of  structure  as  shown  by  discoloration  or  rapid  alterations 
shown  by  a  milk-like  appearance  of  the  tooth  surface. 

Finally,  all  approximal  surfaces  which  could  not  be  explored  are 
si/kfcl.  To  do  this  the  Hoss  is  wrapped  upon  the  index  linger  of  the 
left  hand,  and  with  the  right  is  drawn  between  the  contact  surfaces 
with  a  sliding  lateral  movement.  Care  should  be  exercised  that  no 
injury  be  done  to  the  gingival  margin  of  the  interproximal  space  by 
suddenly  and  forcibly  driving  the  floss  into  contact  with  it.  This  acci- 
dent may  be  effectually  avoided  by  projierly  guarding  and  supporting 
the  fingers  by  contact  with  the  adjacent  teeth.  Practice  gives  facility 
in  determining  by  means  of  thci  silk  the  state*  of  the  parts  in  contact 
with  it. 

In  the  inspection  of  ])revi()us  fillings,  all  margins,  particularly  those 
about  the  cervix  and  beneath  the  gum,  should  be  critically  inspected. 

Lastly,  doubtful  situations  should  be  noted  for  subsequent  examina- 
tion, to  be  made  after  separation. 

(The  tests  for  pulp  exposures  are  considered  in  Chapters  VI.  and 
VII.) 

The  order  of  examination  is  best  conducted  bv  bei;innin<x  at  the 
median  line  of  each  quarter  of  the  denture,  progressing  posteriorly  with 
one  kind  of  observation,  and  returning  to  the  ])lace  of  beginning  with 
another  kind  of  observation. 

The  Chart  Record. — The  chart  record  should  at  the  same  time  be 
carried  on  by  the  princi})al,  or  better  an  assistant,  with  the  view  of 
securing  a  complete  record  of  each  derangement,  for  guidance  and  for 
reference.  The  details  of  the  record  are  indicated  in  a  simple  manner 
by  symbols  which  are  illustrated  by  Fig.  103^  and  explained  by  the  glos- 
sary. These  .symbols  may  be  combined,  where  required,  to  give  fuller 
expression. 

From  this  temporary  record  imjwrtant  oj)erations  when  executed 
may  be  transferred  to  a  permanent  record. 

The  constitutional  condition  and  the  texture  and  apparent  resistance 
of  the  teeth  to  caries  and  attrition  ;  the  inherited  tendency  to  diseases  of 
the  teeth  ;  the  chemical  reaction  of  the  mucous  and  salivarv  secretions ;  the 
state  of  the  general  heath  ;  the  condition  of  the  mucous  membrane  of  the 


THE  CHART  BEGOBD. 


139 


mouth  and  throat;  the  indications  presented  by  the  tongue;  the  dietary- 
habits  and  other  hygienic  relations  ;  the  tendency  to  catarrhal  affections  ; 
the  presence  of  the  rheumatic  or  gouty  diathesis — are  all  questions  which 


Fig.  103. 


S-EX 


c  signifies 

Salivary  calculus. 

EX       " 

To  examine. 

n      " 

A  pulp  nearly  exposed. 

D      " 

A  pulp  probably  exposed 

D      " 

A  pulp  fully  exposed. 

D      " 

A  devitalized  pulp. 

— r  signifies :  In  the  interproximal  space. 

/  "  Attention— re-examine. 

//  "  Superficial  softening. 

///  "  A  carious  cavity. 

•  "  At  the  cervix, 

s  "  To  separate. 

p  "  To  polish. 

enter  into  the  prognosis  and  frequently  largely  determine  not  only  the 
hygienic  directions  to  be  given  to  the  patient,  but  also  determine,  in 
connection  with  the  age  and  habits,  the  important  question  as  to  whether 
the  restorative  operations  shall  be  of  a  permanent  character  or  only  of  a 
temporary  nature  designed  to  preserve  the  teeth  until  restored  normal 
functions  may  make  it  judicious  to  perform  more  enduring  operations. 

The  foregoing  considerations  with  respect  to  the  examination  of  the 
mouth  and  teeth  sufficiently  meet  the  requirements  for  beginning  the 
rational  treatment  of  dental  disorders. 


CHAPTER   Y. 

PRELIMINARY  PREPARATION  OF  THE  TEETH— REMOVAL  OF 
DEPOSITS  AND  CLEANING  OF  THE  TEETH— WEDGING— 
OTHER  METHODS  OF  SECURING  SEPARATIONS— EXPOS- 
URE OF  CERVICAL  MARGINS  BY  SLOW  PRESSURE,  ETC. 

By  Louis  Jack,  D.  D.  S. 


Cleansing  the  Teeth. 

Befoee  restorative  operations  are  commenced  upon  the  teeth  all 
deposits  of  salivary  calculus  upon  them  should  be  removed  and  they 
should  be  cleansed  of  the  covering  of  partially  inspissated  mucus 
which  even  in  persons  of  more  than  ordinary  carefulness  is  liable  to  be 
found  upon  them.  This  film  favors  the  admixture  with  it  of  sedi- 
mentary matter  from  food  substances  and  frequently  has  so  much  con- 
sistence as  to  offer  considerable  resistance  to  its  removal,  and  it  pre- 
vents to  a  degree  the  contact  of  the  naked  brush  with  the  teeth.  Its 
presence  is  in  every  way  detrimental  to  the  preservation  of  the  teeth, 
since  it  not  only  favors  the  adhesion  of  starchy  matters,  but  also  fur- 
nishes, wherever  situated  in  connection  with  these  food  products,  a 
favorable  habitat  for  the  development  of  bacterial  forms  responsible 
for  the  formation  of  the  acid  products  that  are  the  active  agents  of 
enamel  solution.  This  deposit  is  most  frequently  formed  on  the  inner 
and  outer  surfaces  of  the  posterior  teeth,  where  it  invades  the  inter- 
stices and  in  some  cases  cover  all  surfaces  which  are  not  directly  sub- 
ject to  the  friction  of  mastication.  It  should  be  thoroughly  removed 
and  all  surfaces  should  then  be  carefully  polished. 

The  best  means  to  effect  this  is  to  polish  the  parts  with  a  mixture 
of  pulverized  pumice  with  glycerin.  The  glycerin  binds  the  particles  of 
pumice  and  permits  its  retention  upon  the  polishing  instruments.  The 
persistence  of  the  deposit  is  shown  by  the  fact  that  when  the  pumice 
is  applied  it  is  a  moment  before  the  polishing  implement  comes  into 
actual  contact  with  the  enamel.  To  be  suitable  for  this  purpose  the 
pulverized  pumice  should  have  been  elutriated  or  passed  through  a  fine 
bolting  cloth  to  remove  the  coarse  and  irregular  particles  which  if  per- 
mitted to  remain  might  cause  injury  to  the  enamel  surface.  After  the 
removal  a  vitreous  surface  should  be  given  by  quick  friction  with  stan- 

141 


142 


PRELIMISARY  PREPARATION  OF  THE   TEETH. 


Fi(i.  104. 


nic  oxid  ("  tlltty  powder"),  which  also  is  bettor  apj)li(<l  when  eoinbiiied 
witli  u:lyeeriii  or  rubbed  up  with  vaseliii. 

Salivary  calculus  is  ibund  precipitated  at  parts  not  subject  to  free 
friction,  such  as  the  buccal  surfaces  of  the  molars,  the  inner  faces  of 
the   lower   incisors,  and   it  frequently    invades   the   interstices.     These 

(lej)()sits  also  should  I)e  displaced  and  the 
surfaces  polished. 

The  better  appliances  for  tlic  removal 
of  superficial  calculus  are  sickle-shaped 
scalers  of  various  sizes  and  forms,  which 
are  inserted  beneath  the  free  margin  of 
the  gnm,  when  the  direction  of  the  move- 
ment should  be  oblicpicly  toward  the 
occlusal  aspect  to  av<ii(l  injury  to  the 
gingival  attachment  with  the  tooth.  The 
consideration  of  the  removal  of  deeply 
seated  salivary  calculus  where  some 
serious  injury  has  been  caused  by  its  presence  is  treated  of  in  Chap. 
XIX. 

Polishing  the  Triangular  Portion  of  the  Interproximal  Spaces. 
— When  this  is  required  an  efficient  means  is  to  employ  gilling  twine 
of  sizes  proportioned  to  the  space.  This  is  applied  by  looping  one 
or  more  strands  with  a  piece  of  floss  silk,  when  the  silk  is  drawn  up- 
ward into  the  triangle  and  then  is  used  to  pull  the  twine  into  the 
space,  which  being  armed  with  suitable  powders  is  drawn  to  and  fro 
until  the  absence  of  friction  indicates  that  the  surfaces  have  become 
smooth.  The  surfaces  in  contact  may  then  be  polished  by  means  of 
German  silver  strips. 


Abbott's  scalers. 


CARE    BY    THE    PATIENT. 

Coincident  with  the  preparation  above  described  the  patient  should 
be  given  such  instruction  as  will  tend  to  maintain  the  state  of  cleanli- 
ness. The  importance  of  this  should  be  impressed  as  a  necessary 
hygienic  measure  to  preserve  the  teeth.  This  is  to  be  accomplislied  by 
the  use  of  suitable  brushes  and  properly  compounded  powders.  The 
detergent  effect  of  powder  is  principally  due  to  the  particles  becoming 
mixed  with  the  film  of  mucus.  This  action  breaks  up  the  continuity 
of  the  film,  which,  with  the  accompanying  sediments,  is  displaced  by 
the  friction  of  the  brush. 

The  correct  use  of  the  brush  requires  that  it  be  placed  with  some 
degree  of  firmness  upon  the  outer  and  inner  faces  of  the  teeth  and  then 
slightly  rotated  in  a  direction  toward  the  occlusal  aspect.  The  pressure 
drives  the  bristles  into  the  valleys,  and  the  rotary  movement  being  away 


TREATMENT  OF  THE  MUCOUS  SURFACES.  143 

from  the  gum  avoids  injury  to  that  structure.  This  is  the  only  efficient 
method  of  applying  the  tooth-brush,  which  should  be  the  universal 
one.  The  application  of  this  procedure  in  combination  with  the  use 
of  piehs  and  floss  silk  should  maintain  a  correct  hygienic  condition 
of  the  teeth,  upon  which,  in  the  light  of  the  present  knowledge  of  the 
causes  of  solution  of  the  enamel,  depends  the  preservation  of  the  teeth 
from  that  source  of  injury.  It  has  been  shown  that  when  sound 
enamel  becomes  attacked,  the  potent  cause  is  the  fermentation  of 
starchy  deposits  permitted  to  remain  in  contact  with  it. 

It  should  be  understood  that  the  use  of  the  pick  removes  deposits 
from  the  cervical  trir.ngle,  and  that  silk  is  intended  to  sweep  the  more 
contracted  portion  of  the  interstice. 

Further  reason  for  care  is  found  in  the  fact  that  the  mouth  in  an 
unclean  condition  becomes  a  favorable  habitat  for  the  development  of  germs 
some  of  which  may  have  pathogenic  properties  capable  of  affecting  the 
general  health.  It  therefore  becomes  eminently  the  duty  of  the  dental 
adviser  to  enforce  correct  hygienic  conditions  of  the  mouth. 

Much  importance  in  this  connection  should  be  attached  to  the  use  of 
cleansing  preparations  having  inhibitive  action  toward  bacterial  life. 
Those  most  serviceable  contain  hydronaphthol,  which  has  considerable 
efficiency  without  toxicity.  A  three  per  cent,  solution  of  hydrogen  dioxide 
is  also  very  applicable  for  frequent  use.  Formalin  as  an  ingredient  of  a 
wash  is  also  applicable,  but  must  be  prescribed  with  considerable  caution. 

Treatment  op  the  Mucous  Surfaces. 

When  the  gums,  the  membrane  of  the  mouth  or  of  the  throat  are 
inflamed,  treatment  preparatory  lo  operations  upon  the  teeth  should  be 
directed  toward  restoring  these  parts  to  a  normal  state.  Where  the 
inflammatory  condition  is  not  expressive  of  derangement  of  the  alimen- 
tary functions  and  is  the  result  of  some  simple  local  irritation,  the 
condition  will  usually  respond  to  the  topical  action  of  stimulant  tonics. 

It  is  necessary  here  to  discriminate  as  to  whether  or  not  the  inflamed 
surface  has  been  produced  by  neglected  care  of  the  mouth,  which  fre- 
quently induces  a  lax  condition  of  the  gum  from  the  absence  of  friction 
or  by  the  consequences  attending  the  presence  of  bacteria.  These  may 
cause  a  deficiency  of  tone  or  disorders  in  other  portions  of  the  mouth 
and  of  the  throat.  Should  these  conditions  be  present  the  employment 
of  disinfectant  gargles  and  mouth-washes  is  indicated. 

The  presence  of  salivary  calculus  may  also  induce  inflammatory  dis- 
turbance of  the  gums,  and  from  the  points  of  deposit  this  may  extend 
"by  diffusion  over  a  considerable  area.  In  this  connection  deposits, 
either  of  calculus  or  of  sedimentary  accumulations,  posterior  to  the  lower 
third  molars  may  induce  serious  diffuse  inflammation  of  the  contigu- 


144  PRELIMINARY  PRFAWRATION   OF  THE   TEETH 

ous  tissues,  sometimes  extending  to  the  fauces.  For  this  condition  the 
meclmnical  removal  of  the  deposits  coinhincd  with  an  antiseptic  spray 
will  usually  he  restorative. 

Ftir  ditfuse  redness  and  deficient  tone  of  the  mucous  surfaces  a  wash 
composed  of  potassium  chlorate  and  quinin  will  prove  sufficient  in  most 
cases,  as  follows  : 

^.  Potassii  chloras,  5ij  ; 

Quinina^  sulphas,  gr.  iij  ; 

Sp.  reetificatus,  Sj  ; 

Aquae,  5vj. — M. 

S.    For  use  as    a  gargle,  A  dessertspoonful  to  a  wineglass  of 

water,  or  directly  upon  the  gum  in  full  strength  by  means  of 
a  soft  tooth-brush. 

The  fresh  ingredient  has  specific  action  upon  the  mucous  membrane  of 
the  mouth. 

Concurrently  with  the  local  therapeusis  the  employment  of  massage 
of  the  gum  with  the  finger,  either  naked  or  covered  with  a  napkin,  is 
of  considerable  value. 

AVhen  the  conditions  are  catarrhal  or  are  expressive  of  gastric 
derano-ement  onlv  general  treatment  with  (-((ncurrent  attention  to  the 
diet  and  correct  hygienic  relations  will  meet  the  requirements  of  the 
case.  Coincident  with  the  general  treatment  above  indicated,  the 
simpler  operations  upon  occlusal  surfaces  may  be  carried  on. 

In  all  cases  of  initial  treatment  for  children  or  nervous  patients  it 
is  important  to  begin  with  simple  and,  as  nearly  as  may  be,  painless 
operations,  to  accustom  such  patients  to  the  more  or  less  disagreeable 
procedures  and  to  elicit  their  interest  and  co-operation  in  what  is  being 
done  for  their  benefit. 

Cavities  on  Approximal  Surfaces. 

The  preliminary  treatment  of  this  class  of  cases,  on  account  of  the 
limitation  of  space  and  the  necessity  for  somewhat  indirect  application 
of  the  instruments  and  of  the  requisite  force,  necessitates  the  closest 
attention  to  every  detail.  Upon  the  care  here  taken  depends  the 
comfort,  and  furthermore,  indirectly  in  many  instances,  the  health  of 
the  person. 

The  procedure  of  first  importance  is  to  produce  a  sufficient  enlarge- 
ment of  the  interproximal  space.  In  all  cases,  whether  the  teeth  are  in 
apparent  contact  or  whether  they  may,  from  loss  of  substance  on  the 
approximal  aspect,  present  sufficient  room  for  the  management  of  the 
various  procedures,  spacing  is  equally  necessary.  It  is  done  in  order 
that  when  the  stopping  procedures  shall  have  been  completed  the  natural 


SEPARATION   OF  THE  TEETH.  145 

relations  of  the  teeth  with  each  other  will  be  restored.  This  relation,  as 
before  indicated,  is  one  of  apparent  contact  near  the  occlusal  surface 
with  a  triangular  space  at  the  cervix.  The  mechanical  basis  of  this 
arrangement  is  such  that  the  function  of  comminution  of  food  is  better 
eiFected  if  there  is  no  breach  in  the  continuity  of  the  occlusal  aspect  of 
the  denture. 

The  consequences  of  breaches  of  continuity,  especially  in  relation  to 
the  posterior  teeth,  are  often  of  serious  import.  Not  only  may  the  food 
be  driven  into  the  space,  to  the  discomfort  of  the  patient,  but  serious 
injury  of  the  gum  may  follow,  as  in  many  cases  the  tissue  becomes 
inflamed  by  the  impaction  of  food  in  the  enlarged  interspace,  which  in- 
duces peridental  disturbances  and  may  occasion  the  ultimate  loss  of  the 
affected  tooth.  It  is  also  not  unimportant  to  consider  that  the  forms  of 
the  teeth  have  an  esthetic  value,  and  that  the  harmony  of  the  features 
forbids  the  mutilation  of  their  natural  forms. 

Separation  of  the  Teeth. 

Separation  of  the  teeth  is  a  procedure  requiring  care  to  avoid  injury 
and  to  render  the  process  comparatively  painless. 

When  the  teeth  are  mobile,  as  in  the  case  of  children,  the  movement 
is  more  easily  and  more  quickly  made  than  when  the  alveolar  walls  are 
compact  and  Avhen  also  the  teeth  are  in  close  proximity.  In  the  former 
case  the  arch  easily  expands  and  permits  the  teeth  to  yield ;  in  the  other 
case  the  resistance  requires  more  force  to  be  used  and  the  application 
of  it  for  a  longer  period.  In  all  instances  the  force  and  the  material 
used  should  be  adapted  to  the  presented  conditions  and  the  movement 
should  be  sustained  until  the  required  space  is  gained,  it  being  dele- 
terious to  make  repeated  attempts  to  separate  the  same  pair  of  teeth. 
When  the  proper  precautions  are  taken  there  is  no  danger  attending 
the  process  ;  even  the  firmest  structures  of  mature  age  permit  sufficient 
spacing  if  it  be  slowly  and  steadily  done. 

METHODS   OF    MAKING    SEPARATIONS. 

The  means  by  which  these  are  eiFected  are  various  and  the  choice  is 
determined  by  the  amount  of  space  required,  the  time  in  which  it  must 
be  accomplished,  and  the  firmness  of  the  supporting  structures.  Some 
regard  must  also  be  had  for  the  peculiar  susceptibilities  of  the  patient 
to  the  pain  which  may  be  caused  by  the  eifort.  These  methods  are — 
by  immediate  wedging,  which  may  be  made  when  the  fixation  of  the 
teeth  is  not  firm  ;  by  the  swelling  of  firmly  impacted  pellets  of  cotton 
or  of  tape,  and  by  the  resilience  of  strips  of  caoutchouc  where  the  teeth 
are  in  general  contact  and  where  they  are  firmly  fixed. 

Immediate  ■wedging'  is  more  applicable  to  the  front  teeth,  where 
10 


146 


rRi:i.fMf.\.\j!y  rniiwiiATioy  or  riir:  ikkth. 


usually  only  a  small  space  is  ro(juiiV(l,  and  is  a  valiiai)l('  nictliod  <>f 
st'curiuiT  a  so))arati()n  of  the  front  teeth  to  determine  their  condition 
and  to  ])cniiit  polishinjt"^  strips  to  be  inserted  for  the  removal  of  super- 
ficial discolorations  and  for  the  treatment  of  superficial  softening.  Here 
the  procedure  is  to  insert  a  wooden  wedge  between  the  incist)rs  near  the 
incisive  edge,  when  it  is  forced  by  pressure  or  by  percussion  until  a  suf- 
ficient opening  is  effected,  the  space  then  being  secured  by  another  wedge 
of  hard  close-grained  wood  forced  between  the  teeth  at  the  cervix.  This 
process  in  some  instances  is  repeated  by  forcing  farther  the  first  wedge 
and  again  increasing  the  security  by  driving  the  cervical  wedge.  This 
plan  is  not  a])]ilicable  when  the  interspace  at  the  neck  is  quite  angular, 
since  the  fixing  wedge  cannot  be  made  secure,  as  it  then  is  disposed 
to  advance  against  the  gum.  In  this  case  one  of  the  subsequent 
methods  should  be  jiursucd. 

If  the  fixation  of  the  teeth  be  not  firm  they  yield  by  a  slight  enlarge- 
ment of  the  arch  and  by  closing  the  neighboring  slight  spaces. 

Immediate  separations  may  be  effected  by  mechanical  separators, 
notably  the  William  A.  Woodward  (see  Fig.  105),  for  the  front  teeth  and 


Fig.  lOo. 


Fkj.  106. 


Woodward's  separator. 


Perry's  separator  in  conjoint  use  with  matri.x. 


the  Perry  (see  Fig.  106)  for  the  bicuspids  and  molars.  It  should  be 
stated  that  each  of  these  is  preferably  to  be  used  when  some  previous 
space  has  been  made  by  other  means,  following  Avhicli  a  considerable 
increase  of  space  may  be  secured  by  these  appliances. 

Separation  by  the  Swelling-  of  Fibrous  Materials. — These  act  by 
the  capillary  force  of  water  upon  the  fibrous  structure  of  the  material, 
whether  pledgets  of  cotton  or  tape.  This  means  is  also  more  applica- 
ble when  the  fixation  of  the  teeth  is  not  firm,  and  has  the  advantage  of 
being  painless  and  more  readily  tolerated  by  children  and  by  persons 
who  are  impatient  of  pain  or  of  any  form  of  dental  distress. 

Pledgets  of  cotton  are  more  applicable  where  a  ])artial  preliminary 
opening  of  a  carious  cavity  has  been  made,  and  are  more  ai)propriate  for 
the  posterior  teeth.  Here,  when  there  is  no  danger  of  pulp  exposure, 
the  pledgets  may  be  packed  with  considerable  firmness.  In  some 
instances  it  is  advantageous  to  saturate  the  pledget  with  thin  sandarac 


SEPARATION  OF  THE  TEETH.  147 

varnish,  which  attaches  the  fibers,  but  the  time  required  is  much  in- 
creased, as  the  cotton  yields  to  capillary  attraction  only  as  it  loses  the 
resin. 

Tape  is  more  useful  for  the  incisors  ;  it  should  be  of  linen  and  may 
or  may  not  be  waxed.  Its  entrance  is  facilitated  by  an  immediate  pre- 
liminary application  of  a  wooden  wedge. 

Caoutchouc^India-rubber. — When  a  strip  of  india-rubber  is 
drawn  into  a  close  interspace  the  middle  portion  is  constricted  to  great 
tenuity.  The  action  is  by  the  resilience  determining  the  two  exposed 
ends  toward  the  middle,  with  the  result  that  at  length  the  space  attains 
the  size  of  the  thickness  of  the  strip.  It  will  be  perceived  that  the 
physical  force  is  that  of  two  opposed  wedges  acting  with  constant 
power.  The  effect  is  such  that  it  overcomes  the  greatest  resistance  to 
separation  of  the  parts  and  therefore  is  the  most  eflFective  means  which 
we  have. 

Caution  is  required  in  the  use  of  this  material  both  as  to  the  thick- 
ness of  the  rubber  and  as  to  its  purity.  The  pronounced  resilience  of 
pure  rubber  is  generally  painful,  and  in  most  instances  greatly  so. 
The  resilience  can  be  reduced  by  employing  adulterated  specimens 
of  the  material.  The  white-rubber  tubing  of  the  shops  cut  longi- 
tudinally into  various  widths  effects  the  object  with  less  rapidity  but 
surely,  and  generally  without  pain.  The  strip  is  drawn  into  position 
by  a  sliding  motion,  care  being  taken  not  to  force  the  piece  into  contact 
with  the  gum.  To  prevent  the  rubber  being  conveyed  to  the  gum  as 
the  space  enlarges,  a  small  portion  should  extend  slightly  beyond  the 
occlusal  surface.  As  this  kind  of  rubber  is  more  difficult  to  introduce 
when  the  contact  is  close  and  firm,  a  previous  partial  opening  should  be 
made  with  a  piece  of  rubber  dam.  This  method  has  the  value  of  pain- 
lessness, and  also  does  not  usually  necessitate  a  period  of  rest  after  the 
separation  has  been  effected. 

Red  Base-plate  Gutta-percha. — When  it  is  desirable  to  gradually 
effect  considerable  spacing  between  teeth,  where  the  carious  cavities  are 
deep  with  well-defined  boundaries  but  not  involving  the  pulp,  the  method 
of  Dr.  Bonwill,  of  packing  the  cavities  and  the  existing  space  with  a 
sufficient  mass  of  this  form  of  gutta-percha,  produces  expansion  by  the 
continued  force  of  mastication  driving  the  material  upward.  This 
method  also  has  value  in  some  instances  where  it  is  desired  to  force 
the  gum  beyond  the  cervical  margins,  and  may  be  an  acceptable  sub- 
stitute for  aseptic  cotton  for  this  purpose. 

Securement  of  the  Space. — Should  soreness  of  the  teeth  have  been 
caused  by  the  separation,  a  period  of  rest  should  be  given  the  parts  until 
the  distress  has  passed  over.  It  is,  however,  important  that  large  spaces 
should  not  be  long  retained,  since  in  some  instances  alveolar  resorption 


118  PRELIMINARY  PREPARATION  OF  THE  TEETH. 

mav  be  induced  by  the  contiiuuitioii  <»f  the  changed  ])ositi()n.  An  inter- 
val of  two  days  usually  suffices  for  the  pericementum  to  recover  from 
the  disturbance,  when  the  restorative  ])rocedures  may  be  conducted. 

The  retention  of  the  space  may  be  etiected  with  f/uttd-pcrrlia  or  with 
the  pladic  cemeiits, — the  first  being  suitable  when  an  open  cavity 
appears;  zine  plwuphatc  when  from  tiie  smallness  of  the  cavity  gutta- 
percha may  not  be  readily  retained.  0.rychlorid  of  zinc  should  be  used 
wiien  the  cavities  are  shallow  but  sensitive, — the  reason  for  which 
will  appear  later.  It  is  generally  advisable  to  introduce  a  thin  wedge 
of  wood  at  the  cervix  and  in  contact  with  the  gum  to  ])revent  the  re- 
taining material  from  impinging  upon  this  tissue  and  to  give  a  base  to 
support  the  introducing  force. 

Exposure  of  Cervical  Margins. — AVhen  cavities  extend  beneath 
the  gum,  which  frccpicntly  is  the  case  when  caries  has  recurred  above 
the  cervical  margins  of  fillings,  it  becomes  necessary  to  force  the  gum 
somewhat  above  the  carious  border.  This  shoidd  be  done  (piickly 
rather  than  slowly,  otherwise  in  adult  subjects  the  continued  pressure 
may  arouse  diffused  inflammatory  disturbance  of  the  contiguous  tissues. 
Generally  it  is  preferable  first  to  cut  away  the  gum  between  the  teeth 
with  a  straight,  narrow  bistoury,  and  gently  force  red  gutta-percha 
against  the  gum,  gradually  moulding  it  to  the  form  of  the  depression. 
Cotton  pellets  for  this  purpose  are  not  admissible  unless  they  are  anti- 
septically  charged,  for  which  purpose  an  admixture  of  aristol  with  the 
cotton  is  the  most  suitable,  since  not  being  soluble  in  water  it  better 
maintains  the  asepsis.  Cotton  may  be  conveniently  charged  with  aris- 
tol by  saturating  it  with  a  solution  of  aristol  in  chloroform  and  allow- 
ing the  greater  portion  of  the  solvent  to  evaporate  before  introducing 
the  pledget.  The  solution  of  aristol  in  oil  of  gaultheria  may  also  be  used 
for  the  same  purpose. 

When  hypersensitiveness  of  the  gum  tissues  exists  it  is  admissil)le  to 
paralyze  the  sensation  wnth  a  suitable  solution  of  cocain  ])revi()us  to 
introducing  the  pellet  of  either  gutta-percha  or  cotton  fiber.  A  four 
per  cent,  solution  of  cocain  hydrochlorid  applied  upon  cotton  to  the 
sensitive  tissues  will  speedily  relieve  the  condition.  Adrenalin  chlorid, 
1  :  1000,  combined  with  a  weak  solution  of  cocain,  may  be  substituted 
for  the  above. 


CHAPTER   YI. 

PRELIMINARY  PREPARATION  OF  CAVITIES— TREATMENT 
OF  HYPERSENSITIVE  DENTIN  BY  SEDATIVES,  OBTUND- 
ENTS, LOCAL  AND  GENERAL  ANESTHETICS— STERILIZA- 
TION, WITH  A  BRIEF  CONSIDERATION  OF  THE  PHYSIO- 
LOGICAL AND  THERAPEUTIC  ACTION  OF  THE  MEDICA- 
MENTS USED. 

By  Louis  Jack,  D.  D.  S. 


Hypersensitive  Dentin. 

Dentinal  hypersensitiveness  frequently  presents  the  most  serious 
impediment  to  the  procedures  connected  with  the  treatment  of  dental 
caries.  This  condition  must  be  considered  an  exaltation  of  the  normal 
sensitiveness  of  the  dentin,  and  presents  a  wide  range  from  slight  pain 
on  contact  being  made  to  so  high  a  degree  of  sensitiveness  as  to  be  un- 
endurable. In  the  latter  instance  persons  of  the  greatest  capacity  for 
tolerating  pain  will  shrink  from  the  most  careful  instrumentation.  Im- 
mediately upon  the  opening  of  a  carious  cavity  there  usually  are  indica- 
tions of  excitement  of  the  vital  elements  of  the  dentin.  This  con- 
dition may  be  so  slight  as  to  present  no  obstacle  to  further  procedures, 
or  it  may  on  the  other  hand  be  so  excessive  as  to  forbid  all  instru- 
mentation until  a  reduction  of  the  sensitiveness  has  been  effected. 

This  altered  state  of  the  dentin  has  been  considered  by  some  as  one 
of  inflammation  of  the  dentin.  As  the  opportunity  does  not  exist  for 
the  usual  concomitants  of  inflammation  as  pathologically  defined  and 
which  are  induced  by  the  alterations  of  the  circulation  of  the  blood, 
viz.  heat,  redness  and  swelling,  with  exaltation  of  nervous  function 
caused  by  the  additional  supply  of  arterial  blood,  the  term  inflamma- 
tion is  a  questionable  one  to  apply  to  a  hyperesthetic  condition  of 
dentin.  This  manifestation  is  more  logically  explainable  as  a  disturb- 
ance caused  by  changed  relations  of  a  tissue  which  is  naturally  pro- 
tected by  the  enamel  from  irritating  influences.  The  relation  of  the 
enamel  and  the  dentin  is  analogous  to  that  of  the  epidermal  coat  of 
the  skin  and  the  rete  mucosum.  Pain  caused  by  abrasion  of  the 
epidermis  is  immediate  and  acute,  and  occurs  before  the  increased 
supply  of  blood  increases  the  intensity  of  it.     It  is  hence  induced  by 

149 


150  PRELIMINARY  PREPARATION  OF  CAVITIES,  ETC. 

the  altered  relation  (»!'  the  inucosiun.  Tlu'  analogy  is  fnrther  borne  out 
by  the  faet  that  in  each  instance  a  protective  covering  affords  salu- 
tary relief. 

The  normal  sensitivity  <if  dentin  is  n(»t  liigh,  as  is  shown  l»y  an 
immediate  examination  of  a  surface  exposed  by  accident,  Imt  after  a 
few  days  the  denuded  surface  manifests  impatience  of  mechanical 
contact  and  of  applications  of  cold,  which  proves  that  the  altered  rela- 
tions induce  a  condition  of  the  part  similar  to  the  condition  of  the 
skin  when  the  e])idermis  is  broken.  This  appears  to  be  the  case  in- 
dependent of  the  influence  of  chemical  agencies,  as  exaltation  of  sensi- 
tiveness occurs  when  the  fluids  of  the  mouth  are  in  a  normal  state. 
The  same  indications  are  presented  when  a  non-sensitive  cavity  is  pre- 
pared, as  here,  in  case  the  cavity  be  not  protected  by  a  stopping,  the 
same  phenomenon  subsequently  appears. 

Generally  also,  in  such  cases,  if  a  stopping  is  inserted  without  pre- 
viously effecting  a  coagulation  of  the  surface  of  the  cavity,  pain  arises 
upon  reduction  of  temperature.  This  condition  is  designated  as  sec- 
ondary sensitivity,  which  is  caused  by  the  traumatism.  In  some  cases 
of  this  kind  the  pain  becomes  so  great  as  to  require  the  removal  of  the 
stopping  and  the  carbolization  of  the  cavity.  In  extreme  cases  reflected 
pain  in  the  other  teetli  may  appear  in  consequence  of  the  disturbed 
relations  making  an  impression  upon  the  nervous  elements  of  the  pulp. 

When  exposure  of  the  dentin  has  been  brought  about  by  caries,  the 
sensitivity  excited  is  liable  to  be  much  exalted  above  the  normal,  and  is 
only  prevented  from  giving  constant  indications  of  this  condition  by 
the  presence  of  the  carious  matter,  which,  being  a  poor  conductor  of 
heat,  in  a  measure  protects  the  pulp  from  thermal  irritation  and  from 
mechanical  contacts.  This  accounts  for  the  fact  that  while  there  may  some- 
times be  acute  pain  in  the  early  stages  of  decay  of  dentin,  the  irritability 
and  reaction  of  the  pulp  appear  to  become  less  as  the  caries  advances. 

When  the  teeth  are  undergoing  rapid  decay  the  dentin  is  more  sen- 
sitive than  when  the  carious  process  is  slow.  As  the  color  of  the 
carious  matter  gives  some  indication  of  the  rate  of  progress,  we  may 
from  this  indication  form  an  impression  of  the  probable  degree  of 
sensitiveness.  When  the  carious  matter  is  light,  the  action  has  been 
rapid ;  when  it  is  yellow  or  light  brown  it  is  less  active  ;  and  when  it 
is  dark  brown  or  black,  it  has  progressed  very  slowly.  In  some  cases 
of  the  last  character,  when  the  parts  are  subject  to  friction,  spontaneous 
cessation  of  decay  takes  place.  The  parts  are  then  nearly  devoid  of 
sensitiveness.  The  process  by  which  the  dentinal  tubuli  become  oblit- 
erated by  calcific  deposits  is  called  eburnation.  When  the  dentin  be- 
comes exposed  by  attrition,  that  tissue  is  not  as  greatly  irritated  as  it  is 
by  the  progress  of  caries,  since  by  reason  of  the  gradual  loss  of  sub- 


HYPERSENSITIVE  DENTIN.  151 

stance  changes  take  place  within  the  tubules  by  which  their  capacity  to 
convey  sensation  is  diminished  or  obliterated  as  the  case  may  be. 

When  the  gum  recedes,  exposing  the  cementum,  a  very  high  degree  of 
sensitivity  is  often  excited,  which  is  prone  to  decline  by  spontaneous 
changes  of  structure.  There  is  often  here  the  added  influence  of  acid 
conditions  of  the  mucous  secretions  where  they  flow  out  upon  the  teeth 
at  this  point,  and  where,  too,  the  parts  are  not  easily  cleansed.  It  is  a 
notable  fact  in  connection  with  cervical  hypersensitiveness  that  while  it 
persists  these  parts  are  less  liable  to  decay  than  when  loss  of  sensitive- 
ness here  takes  place. 

The  area  of  hypersensitivity  usually  is  not  evenly  distributed 
throughout  the  carious  cavity,  but  has  its  chief  seat  near  the  line  of 
union  of  the  dentin  with  the  enamel,  thus  bearing  out  the  law  that 
sensitivity  is  greatest  at  the  terminal  end-organs  of  the  sensory  nerves, 
with  the  further  qualification  that  the  more  minute  the  fibrillse  the 
greater  may  be  the  acuteness  of  the  sensitivity.  This  fact  is  illus- 
trated by  the  example  of  cavities  in  the  occlusal  surfaces  of  the  molars, 
which  manifest  pain  only  at  the  margins ;  is  only  less  evident  in  the 
cavities  of  approximal  surfaces,  and  is  strongly  shown  in  the  shallow 
buccal  and  labial  cavities,  which  present  their  whole  surfaces  near  the 
line  of  juncture  of  enamel  and  dentin. 

In  most  cases  of  caries,  the  zone  of  highest  sensitivity  is  immediately 
beneath  the  soft  jportion  of  the  decay,  and  when  this  layer  of  dentin  is 
cut  aw^ay  the  pain  becomes  less,  in  some  instances  approaching  the  nor- 
mal. This  statement,  however,  has  force  only  in  the  milder  manifesta- 
tions of  this  condition. 

The  Effect  of  Acid  Conditions  of  the  Oral  Fluids. — In  the  pre- 
vious chapter  some  allusion  w^as  made  to  the  fact  that  an  acid  state  of 
the  oral  fluids  is  detrimental  to  the  teeth  as  promoting  carious  action, 
and  that  alkaline  or  even  neutral  states  have  a  retarding  influence. 
Here  it  must  be  considered  as  an  axiom  that  no  cause  is  so  active  as  a 
primary  influence  in  inducing  excessive  dentinal  sensitivity  as  a  con- 
stant slightly  acid  state  of  these  fluids  ;  and,  conversely,  that  a  neutral 
or  slightly  alkaline  state  is  non-irritating.  These  conditions  should  be 
kept  in  constant  view  in  dealing  with  this  subject. 

The  degree  of  sensitivity  of  dentin  is  modified  by  a  variety  of 
other  general  conditions.  These  are — relative  density  of  the  structure, 
rapidity  of  the  carious  action,  and  the  constitutional  peculiarities  of  the 
person  which  are  connected  most  directly  with  nervous  impressiona- 
bility to  disturbances  of  the  tissues. 

The  rate  of  'progress  of  caries  exerts  considerable  modifying  influence 
over  dentinal  sensitivity.  When  caries  is  of  slow  progress  the  amount 
of  organic  tissue  exposed  to  irritation  is  comparatively  small,  for  the 


152  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

reason  that  the  \vtll-kiu»\vii  salutaiy  and  protective  changes  of  stnietiire 
go  on  coineidently  with  the  sh)\v  inntad.  The  sliglit  ii-ritation  of  sU)\vly 
ailvancing  caries  to  some  extent  exerts  a  stiinnhiting  inHiience  toward 
indncing  tubuhir  deposits.  On  the  other  hand,  when  the  carions  pro- 
cess progresses  with  rajiidity,  rejiarative  efforts  nj)on  tlie  ]>art  of  the 
pnlp  are  paralyzed,  the  organic  elements  of  the  tissue  become  denuded 
to  a  greater  extent,  and  therefore  sensitivity  is  increased  to  a  j)ropor- 
tionate  degree. 

As  these  fibrillar  elements  arc  the  means  of  extending  the  irritation 
to  the  pnlp  of  which  they  are  the  peripheral  prolongations,  it  is  evident 
how  important  a  factor  the  active  advance  of  caries  is,  and  also  to  what 
extent  the  rapidity  of  the  process  increases  the  morbid  concomitants 
of  dental  caries.  It  has  been  pointed  out  that  the  area  of  hypersensi- 
tiveness  generally  pertains  to  a  narrow  line  at  the  outer  limit  of  the 
dentin,  but  in  rapid  caries  this  line  is  a  broader  one. 

The  anatomical  element  of  the  dentin  concerned  with  its  sensi- 
tivity is  contaiiKMJ  witliiii  the  tubuli.  ^^'hil('  the  exact  nature  of  the 
matter  in  these  tubules  has  not  yet  been  certainly  determined,  it  has 
been  shown  to  have  sufficient  consistence  to  permit  of  extension,  as 
in  separating  sections  under  the  microscope  what  appear  to  be  fibers 
have  been  seen.  Also  the  same  appearance  has  been  presented  in  fresh 
specimens  when  the  pulj)  has  been  drawn  away  from  the  dentin.  It 
is  not  difficult  in  reviewing  these  facts  in  connection  with  the  various 
conditions  and  phases  of  dentinal  sensitivity  to  conclude  that  the  exalta- 
tion is  inseparably  connected  with  an  irritated  state  of  the  tubular  con- 
tents. The  variation  in  the  degree  of  sensitivity  of  different  teeth  of 
the  same  mouth — of  those  which  are  side  by  side  and  in  a  similar 
degree  of  progress  of  carious  action  ;  the  profound  fact,  heretofore  stated, 
that  the  dentin  at  a  short  distance  beneath  the  decay  is  much  less  sen- 
sitive ;  that  in  some  instances  sedatives  modify  the  degree  of  pain,  and 
that  coagulants  produce  a  marked  impression  upon  the  capacity  of  the 
tubular  contents  to  convey  sensation,  force  by  inference  the  conclusion 
that  in  diseased  conditions  this  anatomical  element  is  largely  concerned 
in  conveying  im])ressions  to  the  central  organ  of  the  tooth. 

It  is  also  undoubted  that  unusually  high  sensitivity  of  dentin  is  an 
inherent  constitutional  condition  with  some  persons,  and  that  it  pertains 
to  some  families  apparently  as  an  inheritance,  but  may  be  explained  in 
these  instances  as  the  transmission  of  acute  nervous  impressionability. 

In  connection  with  this  subject  should  be  considered  the  further 
observation  that  the  temperature  sense  of  the  teeth  is  various ;  that  with 
some  the  application  of  ice  makes  no  impression  upon  the  teeth  when 
in  normal  condition,  while  with  others  in  the  same  condition  the  least 
cold  induces  pain.  It  would  further  appear  that  the  degree  of  sensitivity 


TREATMENT  OF  DENTINAL  HYPERSENSITIVITY.  153 

when  caries  occurs  bears  some  relation  to  the  relative  tolerance  of  the 
teeth  to  reduction  of  temperature. 

On  these  premises  it  is  not  difficult  to  account  for  the  manifestation 
of  acute  sensitivity,  and  to  build  thereon  an  hypothesis  governing  the 
various  conditions  presented  by  dentin  when  it  is  subjected  to  the  irri- 
tation of  the  carious  process.  These  views  have  steadily  gained  sup- 
port with  the  advance  of  microscopic  study  of  the  tissues,  and  have 
supplanted  the  older  view  that  the  sensitivity  of  dentin  is  a  result  of 
mechanical  vibrations  extending  to  the  dental  pulp. 

Treatment  op  Hypersensitivity  op  the  Dentin. 

Having  considered  the  general  principles  governing  hypersensitivity 
of  dentin,  we  are  prepared  to  enter  upon  a  study  of  the  treatment. 
This  is  to  be  considered  under  the  following  general  lines  :  namely, 
the  therapeutic,  the  chemical,  the  anesthetic,  and  the  mechanical. 

Treatment  of  Slight  Hypersensitivity. — The  first  requisites  to  be 
observed  here  are  a  calm  manner  and  earnest  sympathy,  accompanied 
with  the  assurance  that  if  severity  of  pain  occurs,  mitigating  means  will 
be  resorted  to.  It  is  an  important  and  laudable  object  to  remove  dread 
and  secure  confidence,  which  is  attained  among  other  means  by  select- 
ing at  first  the  simpler  and  less  painful  operations.  When  confidence 
is  secured,  slight  pain  arouses  the  courage  of  the  patient.  The  effect  of 
the  opposite  course  of  indifference  and  harsh  cutting  alarms  the  patient, 
arouses  apprehension,  and  greatly  increases  the  nervous  exaltation. 

In  the  simpler  cases  sharp  instruments  used  with  quick,  light,  and 
rapid  movements  are  called  for.  It  should  in  this  connection  be  noted 
that  cutting  in  this  manner  stimulates  somewhat  the  nervous  force  of 
the  patient,  and  if  the  movements  are  in  very  quick  succession  they 
appear  to  paralyze  the  part ;  the  pain  is  thus  lessened  in  comparison 
with  deliberate  and  slow  instrumentation.  The  movements  of  the  ex- 
cavators should  be  in  a  direction  away  from  the  pulp  rather  than  toward 
it,  and  the  cuts  should  be  by  drawing  the  points  instead  of  pushing 
them  ;  this  is  for  the  reason  that  the  pressure  in  the  latter  case  is  greater 
than  in  the  former. 

When  the  sensitiveness  is  so  great  as  to  interdict  immediate  excava- 
tion and  formation  of  the  cavity,  some  method  of  treatment  of  the  sur- 
face is  required  to  overcome  or  to  confine  it  within  a  tolerable  degree. 

The  Therapeutic  Treatment. — Under  this  head  the  available  reme- 
dies are  moi'phin,  veratrin,  and  cocain, — each  of  them  being  applied 
with  glycerin  as  a  menstruum.  It  should  be  stated  that  neither  have 
much  immediate  effect,  and  therefore  they  should  be  sealed  in  the  cavity 
after  the  opening  in  the  enamel  has  been  prepared,  and  the  softer  caries 
has  been  lifted   and   peeled  off".     The  closure   should  be   effected   by 

13 


154  PRELlMr.WMiY   PREPARATION   OF  CAVITIES,    ETC. 

means  of  gutta-jnnvha,  or  with  what  is  ])rohahly  better,  a  thin  paste  of 
phosphate  of  zinc  laid  over  the  dressing.  After  some  days  tlie  pain  will 
be  fonnd  diminished  in  many  instances.  The  therapensis  is  effected  by 
the  absorption  of  these  sedatives  by  the  partially  disorfranized  tissnes. 
Another  method  of  applying  cocain  is  to  secnre  the  cavity  from  the 
entrance  of  moisture,  and  after  desiccating  the  surface  a  saturated 
pledget  of  vapocain,  a  solution  of  cocain  in  sulfuric  ether,  is  introduced. 
As  evaporation  of  the  ether  takes  place  cocain  is  forced  by  osmosis  into 
the  tissue.  In  cases  of  subacute  sensitivity  this  means  frequently  is 
efficacious,  but  is  of  little  value  in  hypersensitive  conditions.  It  is 
advantngeous  as  preparatory  to  this  line  of  treatment  first  to  neutralize 
the  (iciiJitii  of  the  cavity  with  an  alkaline  solution,  which  may  be  either 
ammonia,  sodium  carbonate,  or  sodium  dioxid,  afterward  removing  the 
excess  of  alkali  by  thorough  washing  with  warm  water. 


Treatment  of  Hypersensitivity  of  Dentin  by  Electrical 

Osmosis. 

Within  a  recent  period  a  means  of  treatment  of  this  condition  has 
become    prevalent    which    has    been    designated    by  the    terms    cata- 

PHORESIS,     ELECTRICAL     DIFFUSION,     and     ELECTRICAL    OSMOSIS.         It 

has  been  demonstrated  that  the  action  of  electrical  currents  conveys 
fluids,  with  the  substances  held  in  solution,  from  the  positive  elec- 
trode toward  the  negative  electrode.  Further,  that  an  electrical 
current  ]>assing  through  a  membrane  accelerates  the  natural  process 
of  osmotic  diffusion  if  the  positive  pole  is  a])plied  on  the  side  of  a 
membrane  or  tissue  from  which  the  osmotic  diffusion  is  taking  place; 
in  case  the  situation  of  the  poles  be  reversed,  the  osmosis  is  retarded  or 
prevented  from  occurrence  or  is  reversed.  This  action  bears  some 
analogy  to  that  which  takes  place  in  electro-metallurgy  when  a  metal 
in  solution  is  conveyed  from  the  anode  (positive  pole),  and  is  deposited 
upon  the  cathode  (negative  pole).  If  the  current  be  reversed  the 
deposited  metal  is  again  taken  up  by  the  solution  and  is  conveyed 
back  again  to  the  other  pole.  This  is  a  law  connected  with  the 
passage  of  electrical  currents  through  fluids  which  are  capable  of  con- 
duction. 

The  following  will  illustrate  the  action  which  takes  place  :  "  If  two 
compartments  separated  by  a  membrane  are  filled  with  a  fluid  and  in 
each  an  electrode  is  placed,  there  is  a  streaming  of  the  fluid  through  the 
septum  from  the  positive  to  the  negative  pole,  so  that  in  time  there  is 
an  increase  in  the  negative  side.  This  osmotic  action,  as  is  well  known, 
occurs  naturally  between  two  fluids  of  unequal  density  from  the  lighter 
to  the  denser  liquid,  but  if  the  anode   is  placed  in  the  denser  liquid 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  155 

and  the  cathode  in  the  lighter  the  natural  osmotic  current  is  not  only- 
overcome  but  is  reversed." 

If  a  substance  containing  water,  as  a  ball  of  wet  clay  or  a  piece  of 
muscular  tissue,  have  an  anode  connected  with  a  current  of  sufficiently 
high  potential  attached  to  one  side,  with  a  cathode  attached  to  the  oppo- 
site side,  the  watery  contents  of  the  substance  are  conveyed  to  and  appear 
in  excess  on  the  cathodal  side ;  at  the  same  time  the  anodal  side  be- 
comes less  damp ;  also,  if  a  capillary  tube  be  filled  with  water  and  an 
anode  and  a  cathode  be  similarly  arranged,  the  water  flows  toward  the 
cathode. 

As  a  membrane  or  tissue  may  be  considered  to  be  a  series  of  tubes 
in  close  contiguity,  it  is  apparent  that  the  movement  of  fluids  must  take 
place  through  them  in  the  direction  the  current  is  passing. 

These  examples  are  an  expression  of  electrical  force.  The  applica- 
tion of  this  law  of  the  passage  of  fluids  from  a  higher  to  a  lower  elec- 
trical potential  is  the  fundamental  process  which  is  employed  in  electrical 
diffusion  of  medicaments.  The  depth  to  which  medicaments  may  be 
conveyed  depends  upon  the  conductivity  of  the  tissue  and  that  of  the 
medicament  which  is  being  applied. 

"  The  cataphoric  action  of  electricity  has  often  been  made  use  of 
experimentally  to  introduce  drugs  into  the  system  through  the  skin. 
In  man  quinin  and  potassium  iodid  have  been  thus  introduced  and 
subsequently  been  detected  in  the  urine." 

As  early  as  1859  Dr.  B.  W.  Richardson  used  this  process  to  pro- 
duce local  anesthesia,  and  completely  demonstrated  its  power  in  this 
direction.  It  has  also  been  clearly  proven  that  when  a  solution  of 
cocain  is  applied  to  the  skin,  its  characteristic  action  upon  the  mucous 
membrane  will  not  here  take  place.  But  when  the  anode  is  wet  with 
the  solution  and  a  galvanic  current  is  passed  through  the  epidermis 
to  the  cathode,  placed  upon  an  indifferent  surface,  anesthesia  is  effected 
over  the  surface  covered  by  the  anode  and  to  an  indefinite  distance 
inward. 

This  effect  is  not  produced  by  the  current  alone,  which  has  been 
abundantly  proved  by  conclusive  experiments,  these  having  been  fol- 
lowed by  demonstrations  confirming  the  above  statement.  When  the 
medicaments  so  applied  have  anesthetic  or  analgesic  properties  their 
characteristic  effects  are  produced. 

When  this  principle  is  applied  to  the  transfer  of  medicaments  it  is 
found  that  they  pass  for  an  indefinite  distance  into  the  contiguous  tissue 
along  with  the  current  from  the  anode  toward  the  cathode,  but  with 
some  degree  of  diffusion ;  the  diffusion  depending  upon  the  resistance 
of  the  tissue  and  upon  the  extent  of  the  surface  of  the  cathodal  (nega- 
tive) electrode. 


15()  PRELIMINARY  PREPARATION  OF  CAVITIES,  ETC. 

GENERAL    PRINCIPLES   INVOLVED    IN    THE    METHOD. 

The  application  of  electricity  requires  the  consideration  of  the 
general  principles  or  laws  governing  its  transmission. 

The  source  of  this  force  is  to  be  found  in  chemical  transformation, 
lender  the  laws  of  the  correlation  of  force  it  is  capable  of  being  con- 
verted into  heat,  light,  magnetism,  and  mechanical  power,  and  may  be 
used  to  disorganize  substances,  when  its  action  is  called  electrolysis.  Its 
movements  are  constant  in  their  direction,  viz.  from  bodies  of  high  to 
those  of  low  potentiality. 

In  perfectly  conducting  substances  electricity  moves  with  entire  free- 
dom under  any  electro-motive  force  however  small. 

In  perfectly  non-conducting  substances  electricity  will  not  move 
under  any  electro-motive  force  however  great. 

In  imperfectly  conducting  substances  electricity  moves  only  on  the 
exhibition  of  intense  electro-motive  force,  the  force  varying  according 
as  the  substance  is  a  more  or  less  indifferent  conductor. 

Electricity  has  two  elemental  properties.  These  are  defined  as  cur- 
rent strength,  designated  by  the  term  amperage;  and  electro-motive 
force,  which  is  termed  its  voltage. 

The  active   energy  of  electricity  depends   upon   the   first   property, 
its  distribution  upon  the  latter.     Since  it  must  be  assumed  that  few 
bodies  are  perfect  conductors,  this  force  or  pressure  is  of  that  degree 
wdiich  may  be  required  in  any  given  case  to  move  the  active  energy, 
the  amjierage,  against  the  resistance  it  meets  with. 
The  unit  of  strength  is  the  AMPi:RE. 
The  unit  of  pressure  is  the  VOLT. 
The  unit  of  resistance  is  the  OHM. 
The  unit  of  jioiver  is  the  avatt. 

A  VOLT  represents  the  electro-motive  force  (E.  M.  F.)  required  to 
impel  one  ampere  of  current  through  one  ohm  of  resistance. 
'  An  AMPfiRE  of  current  is  so  much  as  will  deposit  0.00118  gram  of 
silver  per  second  when  passing  through  a  standard  solution  of  nitrate 
of  silver — or  which  will  decomjiose  0.0932(3  milligram  of  water  in  one 
second.  Hence  the  ampere  is  the  measure  of  rate  of  flow  of  an  electri- 
cal current,  and  in  connection  with  the  voltage  measures  the  energy  of 
the  current. 

The  unit  of  resistance  (ohm)  is  that  degree  of  resistance  which 
will  permit  the  passage  of  one  ampere  of  current  at  one  volt  of 
pressure. 

The  WATT  is  the  power  exerted  by  one  ampere  of  current  at  one  volt 
of  pressure. 

In  the  economic  application  of  electricity  its  transmission  is  effected 


DENTINAL  ANESTHESIA  BY  ELECTRICAL   OSMOSIS.  157 

through  metallic  conductors.  The  resistance  of  these  is  varied  by  the 
character  of  the  metal,  the  cross  section,  and  the  distance.  For  certain 
purposes  other  substances  are  employed  to  effect  greater  resistance  than 
the  metals. 

The  current  strength  flowing  in  a  circuit  is  equal  to  the  pressure 
divided  by  the  resistance. 

The  resistance  equals  the  pressure  divided  by  the  strength. 

The  pressure  equals  the  strength  multiplied  by  the  resistance.  In 
elementary  terms  : 

Amperes  =  volts  -^  ohms. 

Ohms        =  volts  -^  amperes. 

Volts        =  amperes  X  ohms. 

Watts        =  volts  X  amperes. 

It  follows  from  the  formula  that  the'  amount  of  power  and  the  cost 
of  producing  it  is  the  same  whether  the  current  is  of  large  amperage  at 
low  voltage  or  of  small  amperage  at  high  voltage.  Thus  an  incandes- 
cent lamp  may  be  supplied  by  100  volts  at  |-  ampere  or  by  50  volts  at 

1  ampere — the  result  in  each  case  being  50  watts. 

Comparative  Illustration. — Given  a  current  of  100  volts  at  fifteen 
amperes,  and  we  wish  to  use  only  ^  ampere,  the  resistance  t6  be  put 
in  the  circuit  is  found  thus  :  100  v  ^  2^  a  =  4:0  o. 

In  case  we  have  2^  amperes  under  7  ohms  resistance,  it  requires 
17^  volts  to  move  this  degree  of  amperage  through  the  given  resistance, 
thus  :  2|-  «  X  77"  =  17^  v.  If  one  has  a  current  of  110  volts,  and  de- 
sires to  use  a  ^-horse-power  motor,  the  least  amperage  required  is  ly^o"? 
which  is  found  by  dividing  186  watts  by  110.  These  examples  make 
plain  the  means  of  determining  the  character  of  current  required  for 
any  given  purpose. 

Electrical  force  may  be  produced  from  its  source  in  galvanic  cells  by 
arranging  them  in  series  or  in  multiple.  If  in  series  the  voltage  is 
the  sum  of  the  volts  of  the  cells  so  arranged,  and  the  amperage  is  that 
of  each  of  the  cells.  If  joined  in  multiple,  the  strength  in  amperes 
is  the  sum  of  the  amperes  of  the  cells,  and  the  voltage  is  that  of  one 
cell. 

Fig.  107  ^  represents  the  arranging  of  cells  in  series,  the  positive  of 
one  with  the  negative  of  the  next.     In  case  each  cell  has  a  voltage  of 

2  and  an  amperage  of  1  the  electro-motive  force  of  5  cells  will  be  10 
volts  at  1  ampere. 

Fig.  108  ^  represents  the  joining  of  cells  in  multiple.     Here  all  the 
^See  Denial  Cosmos,  December  1896,  p.  998.  ^  Ibid. 


158 


PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 


positive  cloniciits  are  joined  tos;eth(  r  ami    similarly  all   the   negative  to 
eaeh  other.      The  voltage  now  is  2  and  the  amperage  5. 


Vui.  107. 


4-' 


S. 


The  former  method  of  assembling  the  cells  is  designated  as  "high 
tension,"  the  latter  method  as  'Mow  tension."     AVhcn  the  source  is  the 


Fig.  108. 


dynamo,  high  and  low  tension  are  produced  by  the  strength  or  weakness 
of  the  magnetic  field. 

For  electrical  osmosis  the  source  should  be  from  batteries  in  series, 
for  the  reason  that  in  multiple  the  amperage  would  be  too  great  when 
the  voltage  is  of  sufficient  force  to  overcome  the  resistance. 

The  degree  of  electrical  energy  tolerated  by  living  dentin  is  exceed- 
ingly small,  on  account  of  the  peculiar  and  intense  pain  excited  by  the 
transmission  of  electrical  currents  through  the  teeth.  This  is  shown  by 
the  low  initial  voltage  of  the  batteries  used  for  the  purpose,  varying 
from  less  than  5  to  rarely  more  than  20.  But  the  initial  passage  of  a 
current  of  as  high  electro-motive  force  as  these  would  not  be  tolerable, 
and  must  therefore  be  reduced  by  suitable  methods  of  eifecting  re- 
sistance. 

The  apparatus  used  for  this  purpose  is  the  controller,  the  purpose  of 
which  is  through  its  resistance  to  diminish  the  energy  of  the  current  to 
sufficient  weakness  to  meet  the  requirements  of  any  given  case.  All 
forms  are  constructed  on  the  principle  of  the  use  of  materials  which  are 
highly  resistant  of  the  passage  of  electric  currents.     These  substances 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  159 

are  water,  carbon,  graphite,  and  coils  of  wire  of  known  high  resistance, 
the  most  effective  being  of  German  silver.  In  the  case  of  the  latter  the 
degree  of  resistance  is  regulated  by  the  length  and  fineness  of  the  wire, 
the  cross  section  being  reduced  to  the  size  which  will  conduct  the  cur- 
rent without  excessive  heating,  and  to  that  end  it  is  graded  with  refer- 
ence to  the  initial  amperage  of  the  current.  In  comparison  with  silver 
as  a  unit  German  silver  has  a  resistance  of  13.92. 

The  carbon  and  graphite  controllers  usually  are  constructed  in  the 
form  of  a  broken  ring — one  pole  of  the  battery  being  connected  at  one 
end  of  the  ring,  the  other  pole  being  attached  to  an  index  which  travels 
over  this  annular  disk.  This  method  of  construction  gives  a  fine  grada- 
tion of  current  with  high  resistance.  It  may  be  used  in  connection  with  a 
German-silver  wire  rheostat,  where  currents  of  great  strength  are  used 
for  reasons  which  will  appear  later.  In  the  use  of  high-voltage  cur- 
rents, such  as  the  110- volt  circuit,  it  may  be  switched  through  the 
coils  to  a  nearly  definite  low  voltage  by  means  of  a  rlieostat,  when 
the  adaptation  to  the  case  may  be  effected  through  the  graphite  con- 
troller. 

In  the  arrangement  of  the  apparatus  to  effect  electrical  osmosis  the 
battery,  the  controller,  the  instruments  of  observation,  and  the  patient 
are  in  series.  In  the  analysis  of  the  course  of  the  current  it  appears  that 
the  patient  is  another  element  of  resistance,  and  that  dentin  is  more 
highly  resistant  than  the  other  tissues.  In  other  words,  there  are  two 
resistances  in  the  circuit — the  controller  and  the  tissues  of  the  patient. 
The  result  of  the  resistance  of  the  dentin,  unless  the  initial  voltage  is 
small  and  is  reduced  by  the  controller  to  an  infinitesimal  degree,  is  the 
occurrence  of  pain,  which  takes  place  with  different  persons  at  various 
degrees  of  amperage.  The  approach  to  intolerance  of  the  current  is 
designated  the  "  pain  limit."  This  condition  has  been  assumed  by  some 
observers  to  be  caused  by  the  evolution  of  heat  in  the  dentin  con- 
sequent upon  the  resistance  of  this  tissue.  This  view  is  not  now  con- 
sidered to  be  conclusive,  as  the  calculated  elevation  of  temperature  at 
jIq  milliampere  is  not  sufficient  to  account  for  the  degree  of  irritation 
which  occurs  on  increasing  the  rate  of  flow.  This  determination 
leaves  two  other  hypotheses  to  account  for  the  irritation :  a,  the  ten- 
dency of  the  current  to  disorganize  some  of  the  anatomical  elements  of 
the  canaliculi ;  and  h,  the  osmotic  pressure  of  the  migration  of  the 
medicaments.  Here  the  student  is  not  confused  with  consideration  of 
the  complicated  forces  which  are  in  action  connected  with  the  electroly- 
sis of  the  cocain  solution.^ 

The  pain  limit  is  variable  with  different  persons,  and  in  different 

^  See  "The  Foundation  Principles  of  Dental  Cataphoresis,"  Items  of  Interest,  vol.  xx. 
p.  345  et  seq. 


160  PRELIMINAUY   PliKPARATIOy   OF  CAVITIES,   ETC. 

teeth  of  the  same  person.  Witli  some  it  is  rcnclicd  -with  tlie  first 
influx  of  the  current  at  low  voltage  witli  a  record  of  ^\,  inillianipere, 
this  low  record  indicating  higli  resistance  of  dentin  and  ])erniitting  but 
slow  increase  of  the  force  until  after  cocain  lias  diminished  the  sensitiv- 
ity of  the  irritated  surface.  With  others  the  j)ain  limit  may  not  be 
reached  with  a  voltage  of  20  and  a  recorded  amperage  of -j3j  to  y*^  milli- 
ampere.  Yn  respect  of  electrical  irritation  there  must  be  taken  into 
account  also  the  high  nervous  sensitivity  of  some  persons,  as  with  these 
there  usually  appears  greater  susceptibility  to  electrical  irritation. 

The  following  table  of  calctdated  resistances  shows  the  resistance 
in  ohms,  and  the  liability  to  the  generation  of  heat  in  the  dental  tissues 
in  view  of  their  density,  or  the  tendency  to  disorganization  as  previously 
stated,  and  it  suggests  that  care  be  used  in  the  application  of  electrical 
force  for  the  purpose  under  consideration. 

With  15  volts  iuitial  pressure  at  x%  milliampere  in  circuit  the  ohms  are    37,500. 
"     15  "  "  ijs  "  '•  "  150,000. 

"     10  "  "  -^  "  "  "  25,000. 

"     10  "  "  iJjj  "  "  "  100,000. 

"      5  "  "  T*Tr  "  "  "  12,500. 

"      5  "  "  jV  "  "  "  50,000. 

As  the  resistance  of  the  body  including  the  dental  tissues  varies  from 
10,000  to  almost  70,000  ohms,  it  would  appear  necessary  that  the  con- 
troller should  have  at  the  highest  ])oint  a  resistance  of  not  less  than 
400,000  ohms.  This  degree  of  resistance  is  required  to  obviate  the 
effect  of  impulse  which  may  occur  in  closing  the  circuit.  Occasionally 
slight  shock  is  felt  at  500,000  ohms. 

The  varying  resistance  of  the  current  through  the  tissues  depends 
upon  the  density  of  the  dentin,  the  distance  traversed,  the  condition 
of  the  surface  of  the  skin,  and  the  thickness  of  the  adipose  tissues. 

The  average  resistance  of  the  ])atient  as  recorded  by  Dr.  W.  A.  Price 
is  about  25,000  ohms  from  cavity  to  hand,  and  the  difference  of  resistance 
from  tooth  to  hand  and  cheek  to  hand  is  from  3000  to  5000  ohms.  He 
reports  one  ease  where  the  resistance  from  cavity  to  hand  with  a  40  per 
cent,  solution  of  cocain  was  28,500  ohms,  which  on  placing  the  i)ad  on 
the  cheek  was  reduced  to  23,000  ohms. 

Dr.  Price  further  places  the  average  resistance  from  hand  to  tongue 
at  9000  ohms,  and  from  cheek  to  tongue  at  from  3000  to  7000.  This 
would  make  the  resistance  of  the  dentin  nearly  20,000  ohms.  An 
exact  determination  of  the  resistance  of  the  skin  in  any  given  case 
would  enable  a  very  close  approximation  for  the  dentin  to  be  calculated. 

The  condition  of  the  cavity  as  to  relative  moisture  and  the  degree 
of  saturation  of  the  pledget  of  cotton  containing  the  anesthetizing  agent 


DENTINAL  ANESTHESIA   BY  ELECTRICAL    OSMOSIS.  161 

as  well  as  the  percentage  of  the  medicament  exert  a  considerable  quali- 
fying control  of  the  resistance,  as  appears  from  the  experiments  of 
Dr.  Price.  When  a  section  of  dentin  partially  dry  on  the  surface  had 
a  resistance  of  30,000  ohms,  after  being  dried  and  saturated  with  a  40 
per  cent,  solution  of  cocain  the  resistance  was  reduced  to  4500  ohms. 

The  principles  here  stated  and  the  facts  presented  apparently  demon- 
strate the  importance  of  careful  selection  of  the  degree  of  voltage  at 
the  battery;  of  the  use  of  a  relatively  low  amperage  to  the  voltage; 
of  the  necessity  of  controlling  the  current  within  the  boundary  of  the 
pain  limit ;  of  the  importance  of  avoiding  impulses  of  current  by  rapid 
advancement  or  by  movements  of  or  displacements  of  the  anode ;  and 
of  attention  to  the  maintenance  of  a  constantly  moist  state  of  the  anodal 
and  cathodal  contacts. 

These  principles  and  facts  have  led  to  the  application  of  galvanic 
currents  for  the  production  of  a  state  of  anesthesia  of  hypersensitive 
dentin  ;  and  the  results  of  experimentation  in  this  direction  have  proven 
that  the  same  effects  have  followed  here  as  have  occurred  in  the  softer 
tissues. 

The  extreme  sensitiveness  of  the  teeth  to  electrical  currents  and  their 
resistance  to  the  passage  of  electrical  force  were  obstacles  to  the  earlier 
application  of  this  method  of  treatment  in  dentistry.  The  absence  of 
means  to  control  the  current  strength  (the  amperage)  and  to  reduce  the 
pressure  (the  voltage)  to  the  capacity  of  the  teeth  prevented  experi- 
mentation in  this  direction  until  within  a  comparatively  recent  period. 

It  follows  from  the  above  statements  that  the  current  strength  that  is 
tolerable  at  the  commencement  of  the  application  is  so  small  as  to  be 
scarcely  measurable  in  many  instances.  To  produce  this  small  current, 
either  the  battery  voltage  must  be  low  or  the  resistance  in  the  controller 
exceedingly  high. 

Any  form  of  battery  which  is  constant  when  the  amperage  of  the 
individual  cell  is  from  one-fourth  to  one-half  of  an  ampere  will  have 
sufficient  current  strength.  The  E.  M.  F.  may  be  from  one  to  two 
volts  per  cell. 

The  voltage  required  to  produce  the  necessary  electro-motive  force  in 
an  application  to  the  teeth  to  produce  dentinal  anesthesia  varies  from 
five  to  thirty.  For  children  and  where  the  teeth  are  apparently  not 
dense,  ten  cells  sometimes  are  sufficient,  but  generally  fifteen  to  twenty 
are  needed.  The  cells  should  be  arranged  in  series  and  connected  in  a 
manner  which  enables  the  selection  of  any  number  to  produce  the  re- 
quired E.  M.  F.  for  any  given  case  and  to  permit  an  increase  of  cells 
during  the  administration. 

The  most  important  condition  of  the  electrical  force  for  the  purpose 
is  that  the  amperage  shall  he  inconsiderable,  since  high  amperage  is  intol- 
erable to  the  teeth.  As  the  most  efficient  results  are  produced  when  the 
U 


1(;2  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

recorded  amperai^cMs  not  over  tliree-tcntlis  of  a  iiiilliani|u"Tc,  the  use  of  a 
current  ot"  liiuh  anijuTaLTc  is  unneces!*arv,  and  it  i-  attcndccl  with  distress. 
Jlitrli  voltage  is  ecjually  painful,  as  tlie  endeavor  to  force  tlic  current 
against  the  resistance  of  the  dentin  results  in  eleetrleal  irritation,  as 
already  described. 

The  chlorid  of  silver  cell  is  probably  the  one  best  suited  for  the 
jnirpose,  as  its  electro-motive  force  remains  practically  constant  under 
various  conditions.  The  E.  M.  F.  of  each  cell  is  about  one  volt ;  the 
internal  resistance  eight  ohms;  the  strength  one-fifth  of  an  amp5re. 
This  battery  on  account  of  its  constancy  and  durability  is  largely  used 
in  electro-medical  apparatus.  It  is  now  furnished  dry,  and  is  more 
acceptable  as  being  less  troublesome  on  this  account. 

The  dry  Leclanch^  battery  is  also  one  of  the  best  forms,  as  it  is  an 
open-eireuit  battery.  As  long  as  the  circuit  is  open  there  is  no  action 
in  the  cell  and  consequently  there  is  no  loss. 

At  present  these  two  forms  of  galvanic  battery  cell  appear  to  be  the 
kinds  best  adapted  for  the  purpose  of  inducing  electrical  osmosis. 

The  life  of  a  chlorid  of  silver  dry  cell  battery  is  stated  to  be  700 
hours  of  eataj)horic  \\'ork  under  a  high  resistance  of  tissue,  but  it  must 
be  remembered  that  the  continuance  of  energy  of  all  forms  of  battery  is 
varied  by  the  resistance  and  the  conversion  of  electrical  energy  into  heat 
by  the  controll(>r  which  regulates  the  amperage  and  the  voltage.  This 
principle  applies  to  all  sources  of  electrical  force. 

The  controller  which  at  present  appears  best  adapted  to  be  interposed 
between  the  battery  and  the  anode  is  the  Willms  controller,  which,  as 
before  stated,  should  be  constructed  with  a  resistance  at  the  highest 
point  of  at  least  400,000  ohms.  The  gradations  of  resistance  decrease 
from  this  through  112  contact  points.  These  permit  a  very  gradual 
reduction  of  the  resistan(;e  as  the  switch  is  conveyed  from  point  to 
point  in  the  circle.  This  controller  also  has  the  advantage  of  being 
moderate  in  cost  and  easily  procurable. 

An  important  adjunct  of  any  apparatus  is  a  reliable  laiUkimpPremeter. 
This  should  have  a  scale  to  record  divisions  of  fortieths  of  a  milliampere, 
from  the  fact  that  the  amperage  of  the  current  through  the  dentin  is  fre- 
quently efficient  at  less  than  two-tenths  of  a  milliampere.  The  milli- 
amperemeter  also  aids  in  detecting  leakage  of  current,  as  where  the 
indicated  amperage  exceeds  four-tenths  milliampere  there  is  reason  to 
suspect  imperfection  of  the  insulation  of  the  tooth.  In  this  case  a 
longer  period  than  usual  will  be  required  to  effect  the  anesthetization, 
and  the  degree  of  this  effect  may  be  less. 

The  use  of  the  direct  current  generated  by  the  dynamo  is  of  ques- 
tionable  utility  as  compared   with  the  current   from   a  battery.     The 


DENTINAL  ANESTHESIA   BY  ELECTRICAL    OSMOSIS.  163 

current  from  the  dynamo  is  subject  to  changes  of  voltage  and  the 
amperage  is  liable  to  fluctuations  consequent  upon  alterations  of  the 
load  in  the  general  circuit.  This  instability  causes  a  series  of  pulsat- 
ing shocks  upon  sensitive  dentin  and  the  pulp,  which  react  with  the 
expression  of  pain.  The  possibility  of  the  transmission  of  severe 
shock  through  accidental  grounding  or  defective  apparatus  where  such 
excessive  voltage  is  used  is  another  and  sufficient  reason  why  the 
steady  and  low-voltage  current  of  a  battery  is  preferable  for  this  class 
of  operations. 

TECHNIQUE    OF    THE    ADJIINISTRATION. 

At  the  present  period  cocain  has  been  found  to  be  the  most  effective 
anesthetic  for  obtunding  dentinal  sensitivity  by  electrical  osmosis.  It 
is  used  in  strength  varying  from  12  to  24  per  cent.,  and  by  some  as 
high  as  40  per  cent,  has  been  used ;  11-  grain  of  one  of  the  salts  of 
cocain  added  to  5  minims  of  water  procures  a  solution  of  24  per  cent. ; 
to  7^  minims,  18  per  cent.  ;  to  10  minims,  12  per  cent. 

The  salts  of  cocain  which  have  been  used  are  the  hydrochlorid  and 
the  citrate.  Each  is  efficient  in  the  strength  stated.  The  resistance  of 
cocain  citrate  is  for  12  percent,  solution  234  ohms;  for  24  percent. 
153  ohms.  The  resistance  of  cocain  hydrochlorid  is  for  12  per  cent, 
solution  80.85;  for  24  per  cent.  61.25.  These  provings  indicate  that 
the  hydrochlorid  is  the  better  salt  of  cocain  for  the  purpose.^ 

The  tooth  to  be  operated  upon  is  isolated  by  means  of  a  rubber  dam 
and  is  ligated  at  the  cervix  to  prevent  leakage  of  current.  If  there  are 
metallic  fillings  in  the  tooth,  these  should  be  covered  Avith  a  coat  of 
varnish  carefully  laid  on  and  dried.  This  precaution  does  not  always 
possess  the  value  claimed  for  it,  as  the  dentin  beneath  a  metal  filling, 
because  of  its  density  or  lack  of  porosity,  will  not  convey  the  current 
as  well  as  the  carious  matter  and  the  softer  dentin  of  the  fresh  cavity. 
In  some  cavities  where  caries  has  occurred  at  the  cervix  above  gold 
fillings,  and  which  do  not  permit  of  complete  isolation  of  the  fillings, 
the  cataphoric  influence  is  not  interfered  with. 

The  carious  matter  should  not  be  completely  removed  and  need  only 
be  partially  dried.  The  cavity  is  loosely  filled  with  a  small  pledget 
of  lint  saturated  with  the  solution  of  cocain.  The  anode,  the  point  of 
which  is  of  platinum,  is  covered  with  a  thin  stratum  of  lint  which  is 
dipped  in  the  solution  and  inserted  in  the  cavity  in  contact  with  the 
pledget  previously  introduced.  The  cathode,  which  should  be  at  least 
one  and  a  half  inches  in  diameter,  is  placed  at  a  convenient  place  on 

^The  writer  is  indebted  for  the  determination  of  these  resistances  of  cocain  solutions, 
etc.,  to  Mr.  A.  W.  Schramm,  of  the  University  of  Pennsylvania. 


164  PRELIM  IS  Mi  Y  PREPARATION  OF  CAVITIES,   ETC. 

the  face  or  neck.  Tlu'  desiivd  number  of  colls  arc  placed  in  cinuit 
with  the  controller  at  zero. 

All  bcinji:  ready,  the  switch  is  ])laccd  on  the  first  contact  point.  At 
this  moment,  however  great  the  resistance  of  the  controller,  a  slight 
sensation  is  sometimes  exjierienccd,  hut  at  once  the  switch  may  be 
passed  slowly  over  the  contacts  until  som(>  sign  from  the  j)atient  indi- 
cates that  the  current  is  being  felt.  Here  it  is  retained  until  subsidence 
of  the  sensation  occurs,  when  the  resistance  of  tiie  controller  should 
be  very  gradually  lessened.  This  process  is  continued,  keeping  con- 
stantly within  the  limit  of  pain  ;  at  length  the  switch  may  be  more 
rapidly  advanced  to  the  last  pin.  When  this  can  be  done  without  thrill, 
the  indication  is  that  anesthesia  is  complete.  The  switch  is  then  rnrried 
back  to  the  zero  point,  when  the  excavation  may  be  conducted. 

AVhere  it  is  necessary  to  remove  the  rubber  (as  the  solution  of  cocain 
is  strong)  the  preparation  should  be  previously  washed  away  to  prevent 
any  of  it  from  being  swallowed. 

The  period  of  admiuisfrafion  varies  from  eight  to  fifteen  minutes 
in  ordinary  cases  where  the  indicated  amperage  is  from  -^^  to  -f^  milli- 
ampere.  Wlien,  however,  the  dentin  is  dense,  as  where  denudation  has 
taken  place  by  attrition,  a  longer  time  is  required  to  effect  penetration 
by  the  cocain.  Also  where  from  any  condition  the  indicated  amperage 
at  first  is  2^0  niilliampere  or  less,  time  and  patience  arc  demanded. 
The  loss  of  time  is  more  apparent  than  real,  since  there  usually  is  a 
direct  relation  between  the  pain  limit  at  very  low  amp&rage  and  high 
sensitivity ;  what  is  apparently  lost  in  the  time  of  the  application  is 
gained  in  the  after  facility  of  instrumentation. 

The  sphere  of  the  action  extends  throughout  the  cavity,  but  to  a 
somewhat  less  degree  at  the  extreme  lateral  margins,  and  more  particu- 
larly at  the  occlusal  margin.  Here  usually  no  more  than  a  normal 
degree  of  sensitivity  is  found,  which  appears  to  be  due  to  the  fact  that 
in  making  the  retentive  undercutting  this  procedure  may  extend  beyond 
the  sphere  of  the  complete  influence  of  the  cocain.  The  effect  is  most 
pronounced  when  the  application  is  made  directly  to  the  carious  matter. 
In  this  case  the  diffusion  is  greater  than  Avhen  the  caries  is  freely  re- 
moved, for  the  reason  that  in  the  latter  case  the  current  seeks  the  line  of 
least  resistance  toward  the  pulp.  It  follows  from  this  that  when  all 
parts  of  the  cavity  are  equidistant  from  the  pulp,  the  action  should  be 
more  effective  throughout  upon  the  surface  of  the  dentin.  This  is 
proven  to  be  the  case  from  the  profound  effect  in  cavities  upon  buccal 
and  labial  surfaces  and  in  shallow  cavities  of  occlusal  surfaces.  Besides 
the  less  diff'usion  of  the  cocain  when  the  carious  matter  is  removed, 
a  decree  of  electrical  force  which  in  the  former  case  is  easilv  toieratcfl 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  165 

becomes  painful.  These  facts  make  conclusive  the  importance  of  retain- 
ing some  of  the  carious  contents  of  the  cavity. 

An  explanation  of  the  influence  of  the  current  is  found  in  the  prin- 
ciples and  examples  given  on  page  154.  As  the  anode  is  put  in  con- 
nection with  the  lint  saturated  with  the  cocain  solution  the  fluids  of  the 
tooth  advance  toivard  the  pulp  through  the  canaliculi,  their  place  being 
taken  by  the  solution  of  cocain.  At  the  same  time  it  is  observed 
that  loss  of  fluid  from  the  lint  occurs,  necessitating  additions  to 
maintain  the  proper  M^etness,  some  loss  of  water  taking  place  by 
evaporation. 

Conditions  Influencing  Tolerance  of  the  Current. — As  already  stated, 
when  the  electrical  force  is  brought  into  connection  with  the  carious 
matter  the  irritation  caused  by  the  current  is  of  trifling  degree  and 
soon  subsides,  indicating  that  the  anesthetic  effect  has  been  produced  ; 
but  when  the  cavity  is  denuded  of  caries  the  above-stated  degree  of 
current  force  is  not  so  tolerable,  the  irritation  continues  longer  and 
does  not  subside  in  the  same  manner,  but  the  effect  upon  the  tissue  is 
nearly  if  not  quite  as  marked.  The  nearer  the  bottom  of  the  cavity 
is  to  the  pulp,  the  greater  the  irritation.  Hence  in  this  condition  it 
becomes  necessary  to  begin  with  a  low  degree  of  voltage.  While  in 
the  one  case  fifteen  cells  may  be  selected,  in  the  other  ten  cells  are 
more  satisfactory. 

To  avoid  the  removal  of  caries  the  condition  of  the  dentin  as  regards 
sensitivity  should  be  tested  at  the  line  of  its  connection  with  the 
enamel. 

Some  stress  has  been  laid  upon  the  necessity  for  rendering  the  solu- 
tion of  cocain  more  highly  conductive.  This  claim  is  probably  more 
theoretical  than  practical  in  its  character,  since  experience  with  the 
solutions  given  indicates  that  the  conductivity  is  sufficient,  and  that  the 
resistance  is  more  to  be  looked  for  in  the  dentin  than  in  the  solution, 
and  that  when  the  tooth  has  become  tolerant  of  the  current  at  a  com- 
paratively low  voltage  an  increase  of  pressure  of  the  current  is  suf- 
ficient to  complete  the  anesthesia. 

The  form  of  the  platinum  anode  should  be  such  as  to  permit  its 
easy  entrance  into  the  cavity  when  its  point  is  covered  with  a  layer  of 
absorbent  lint.  For  all  cavities  in  the  approximal  surfaces  and  in  most 
occlusal  positions  an  excellent  form  of  anode  is  made  by  curling  the 
end  of  a  fine  platinum  wire  (No.  25)  into  a  flat  knot,  or  forming  it  in  a 
loop.  On  the  loop  a  properly  sized  piece  of  lint  may  be  gathered. 
This  may  be  packed  into  the  cavity  and  secured  with  additional  lint 
when  required.  This  method  is  a  self-sustaining  one.  The  connection 
between  the  free  end  of  the  anode  and  conducting  cord  is  made  with  a 
spring  clip,  as  shown  in  Fig.  110. 


166 


PRELIM  IS  ARY  PREPARATIOX  OF  CAVITIES,   ETC. 


For  labial   and   hiiccal   surl'art's   two  or  more  small   points  to  sorew 
into  a  ootimioii  liaiulU'  are  sufiiciont  (see  Fig.  109).     These  have  to  be 


Fi.i.  MX.). 


Dental  anodes  for  cataphoresis. 


held  hi  situ.     A  iorm  and  arrangement  to  make  these  self-sustaining 
offers  an  important  field  for  inventive  skill. 


Fig.  110. 


Snap  and  wire  electrode. 


A  convenient  cathode  electhode  is  shown  in  Fig.  111.     Tn  this 
the  surface  is  recessed  to  receive  a  disk  of  amadou  (spunk)  or  cottonoid, 


Fig.  111. 


Cathode  for  cataphoresis. 

one  and  a  half  to  two  inches  in  diameter,  which  retains  an  abundance 
of  a  solution  of  sodium  chlorid  to  maintain  contact.  The  surface  is 
platinized  to  prevent  corrosion.  The  reverse  side  has  the  usual 
socket  to  receive  the  conducting  cord,  which  is  placed  in  a  projection 
intended  to  pass  through  an  opening  in  the  band  which  supports  the 
rubber  dam. 

It  is  indifferent  where  this  electrode  is  placed  ;  the  objects  to  be 
attained  are  to  lessen  the  resistance  as  much  as  possible  and  to  secure 
constant  apposition  with  the  surface  with  which  it  is  connected.  If  the 
person  be  comparatively  lean,  the  face  before  the  ear  is  to  be  preferred. 
When  there  is  much  adipose  tissue  on  the  face,  the  usual  negative  hand 
electrode,  covered  with  a  small  wet  napkin  to  maintain  close  contact, 
may  be  iietter  than  the  application  to  the  face  ;  but  in  general  the  nearer 


DENTINAL  ANESTHESIA   BY  CHEMICAL  AGENTS.  167 

the  cathode  is  phiced  to  the  angle  of  the  jaw,  the  quicker  and  surer  is 
the  result  of  the  administration. 

The  action  of  cocain  administered  in  this  manner  is  profound.  The 
effect  is  primarily  upon  the  contents  of  the  canaliculi,  as  is  shown  in 
the  cataphoric  treatment  of  shallow  cavities.  After  superficial  anes- 
thesia has  been  established  much  lateral  cutting  will  later  elicit  a  degree 
of  pain;  in  deep  cavities  nearing  the  pulp,  the  effect  extends  to  that 
organ.  The  recurrence  of  sensitivity  takes  place  within  a  few  hours. 
No  injury  appears  to  follow. 

This  method  of  treatment  is  little  required  where  the  degree  of 
hypersensitiveness  is  such  as  to  yield  to  desiccation  of  the  dentin  or 
the  application  of  carbolic  acid  combined  with  caustic  potassa  ("  Robin- 
son's Remedy  ").  But  when  the  pain  attending  excavation  requires 
active  treatment,  such  as  the  employment  of  zinc  chlorid  or  general 
anesthesia,  the  cataphoric  method  is  far  preferable  to  either,  and  is 
nearly  certain  to  give  relief.  The  condition  where  cataphoresis  is  most 
required  is  when  the  impatience  of  the  dentine  to  mechanical  irri- 
tation is  extreme.  Usually  in  this  case  the  condition  extends  deeply. 
The  results  of  successful  cataphoresis  are  marvellous,  and  it  may  be 
truly  stated  that  no  advance  of  recent  years  in  the  therapeutic  treat- 
ment of  the  teeth  is  comparable  to  this.^ 

Cautious  excavation  is  required  after  cataphoric  treatment,  as  in  the 
absence  of  sensitivity  indiscriminate  cutting  may  needlessly  encroach 
upon  the  pulp.  In  case  exposure  really  exists  the  action  of  cocain  does 
not  prejudice  conservative  treatment  of  the  pulp.  When  devitalization 
is  determined  upon,  the  anesthesia  facilitates  this  procedure.  As  stated 
in  Chapter  XVI.  cocainization  may  be  then  continued  either  cata- 
phorically  or  by  instillation.  Should  arsenous  acid  be  selected  as  the 
devitalizing  agent,  cocainization  may  be  used  as  a  preparatory  measure 
to  lessen  arsenical  irritation. 

The   Chemical  Treatment. 

Under  this  head  are  included  the  application  of  warmed  air,  the  use 
of  coagulants,  notably  carbolic  acid  or  zinc  chlorid,  and,  in  combination 
with  these,  one  of  the  essential  oils,  preferably  oil  of  cloves,  for  reasons 
stated  below. 

Warmed  Air. — This  method  is  of  great  value  in  subacute  cases. 
It  is  especially  serviceable  for  the  cavities  of  incisors  and  biscuspids  and 
others  of  easy  access.     The  effect  here  produced  is  due  to  the  depriva- 

^  For  further  study  of  this  subject,  see  "  International  System  of  Electro-Thera- 
peutics," Section  C,  p.  1  et  seq.,  Peterson;  also,  "Foundation  Principles  of  Dental 
Cataphoresis,"  by  Dr.  Price,  Itevis  of  Intrrest,  vol.  xx.  p.  345. 


168 


PRELrMIXARV   I'liKPAHATION  OF  CAVITIES,   ETC. 


turn  of  the  tissue,  to  a  (greater  or  l('.<s  degree,  of  one  of  its  I'lcmcnts,  viz. 
water,  and  it  is  more  effective  in  teeth  of  dense  stnicturc,  since  the  sur- 
face of  these  is  more  easily  desiccated  than  the  softer  teeth.  If  it  were 
possible  to  remove  all  the  water  of  the  tissue  from  the  surface  to  the 
dej)th  of  the  iri'itated  })art  all  sensitivity  would  therehy  he  overcome,  but 
irencrally  this  can  be  only  imperfectly  done  ;  nevertheless,  the  benefit 
is  generally  considerable.  This  means  is  easily  and  (piickly  applied, 
and  as  it  presents  the  simplest  method  in  the  cases  where  it  is  applicable 
it  forms  therefore  the  easiest  and  most  available  procedure  for  this 
purj)ose. 

The  warmed  air  may  be  produced  by  heating  the  bulb  of  a  waiim- 
AIR  SYEINGE  (Fig.  112)  over  a  lamp  or  Bunsen  burner,  when  a  eontinu- 

Fi(i.  112. 


Warm-air  syringe. 

ous  stream  of  air  is  forced  through  the  nozzle  into  the  cavity.  Some  tact 
is  required  to  deliver  the  heated  air  in  a  manner  to  cause  the  least  pain 
by  its  impingement.  If  the  nozzle  be  held  too  far  away  from  the  tooth 
the  stream  of  air  in  i)assing  through  the  atmosphere  takes  along  with  it 
so  much  of  the  surrounding  cool  air  as  to  cause  pain,  and  if  held  too 
close  the  heat  is  ecpially  painful.  In  all  cases  the  abstraction  of  the 
water,  even  when  the  degree  of  heat  is  well  balanced,  produces  some 

Fig.  113. 


Electric  warm-air  syringe. 


unpleasant  sensation,  which  soon  passes  away  and  after  a  few  moments 
the  case  is  reduced  to  a  state  of  slight  and  simple  sensitiveness.     The 


DENTINAL  ANESTHESIA  BY  CHEMICAL  AGENTS.  169 

blast  should  be  gently  ajjpliecl  at  first  at  intervals  of  a  couple  of  sec- 
onds ;  when  the  pain  induced  by  the  abstraction  of  the  water  some- 
what diminishes,  the  force  should  be  increased  and  made  continuous, 
when  in  most  cases  the  excavation  may  be  continued.  The  air  may 
also  and  preferably  be  heated  by  an  electric  warm-air  syringe  (Fig. 
113),  which  has  the  advantage  of  maintaining  an  even  degree  of  heat. 

As  stated  before,  this  means  is  of  less  use  with  soft  teeth,  and  fre- 
quently fails  when  the  teeth  have  a  high  grade  of  sensitivity  which 
appears  to  be  due  to  constitutional  conditions, — where  the  sensitivity  is 
not  confined  to  the  surface  of  the  tissues  immediately  beneath  the  caries 
but  pertains  to  the  whole  of  the  dentin. 

Preparatory  to  the  use  of  heated  air,  the  application  to  the  cavity 
of  absolute  alcohol  is  serviceable,  on  account  of  its  high  affinity  for 
water. 

Carbolic  Acid. — This  substance,  while  of  little  efficiency  in  con- 
trolling acute  sensitivity,  is  of  benefit  in  moderating  that  condition. 
Its  efficacy  is  increased  by  adding  to  it  a  proportion  of  one-third  of  oil 
of  cloves,  which  latter  has  some  anesthetic  influence.  When  other 
more  active  means  are  not  admissible  and  the  effect  is  not  immediately 
satisfactory,  a  better  result  is  produced  by  placing  this  combination  in 
the  cavity  and  sealing  it  in  with  zinc  phosphate  until  a  subsequent 
visit,  as  before  described.  On  account  of  the  feeble  affinity  of  carbolic 
acid  for  water,  the  obtundent  effect  is  facilitated  by  the  previous  partial 
desiccation  of  the  surface  of  the  cavity  by  warm-air  blasts.  Carbolic 
acid  in  combination  with  caustic  potassa,  equal  parts  of  each  (Robin- 
son's Remedy),  is  often  of  much  service  in  subacute  sensitivity.  The 
preparation  should  be  laid  in  the  cavity  in  contact  with  the  denuded 
dentin  and  should  be  allowed  to  remain  until  it  deliquesces. 

Carbolic  acid  in  combination  with  tannic  acid  is  also  serviceable  when 
sealed  in  the  cavity  by  an  impermeable  temporary  stopping. 

Zinc  Chlorid. — Of  all  substances,  when  not  interdicted  by  proximity 
of  the  dental  pulp,  zinc  chlorid  is  the  most  efficient  of  the  topical 
remedies  for  the  condition  under  consideration.  Its  action  is  explained 
by  the  double  power  of  its  affinity  for  water  and  its  extreme  coagulating 
effect  upon  albumin.  It  is  evident  that  if  the  tissue  be  deprived  of  two 
of  its  elements  the  function 'of  sensitivity  must  be  impaired  or  destroyed. 
In  the  degree  to  which  this  action  takes  place  the  tissue  loses  its  capacity 
for  irritation. 

As  zinc  chlorid  in  concentrated  solution  is  an  active  escharotic  to 
organic  tissue,  it  must  be  employed  with  caution.  After  paralyzing  the 
vital  resistance  of  the  part  its  action  is  by  combining  in  definite  propor- 
tions with  the  albuminous  elements  of  the  structure.  It  has  the  fur- 
ther property  of  an  excessive  affinity  for  water,  which  enables  one  to 


170  PRELIM  ISA  RV   PREFARATIOX   OF  CAVITIES,   ETC. 

arrest  its  action  by  sutiii-iciit  ii  ii<;ati(»ii  to  iviiiove  all  traces  of  the  salt 
from  the  cavity.  Its  active  coaiiulatiiii::  pnwcr  renders  it  a  valuable 
afjent  in  excessive  dentinal  sensitivity  where  there  is  not  close  proximity 
of  the  pnlp,  and  its  safety  is  ensnred  by  tiie  facility  with  which  any  re- 
mains of  the  salt  may  l)e  taken  np  with  water. 

Unless  emploved  in  excess  tmd  too  lont;-  continned  the  acti(»n  of  the 
zinc  chlorid  does  not  pass  beyond  the  zone  of  the  exalted  tissne,  which, 
as  we  are  aware,  generally  is  ol"  limited  (lej>th.  The  cessation  of  the 
pain  prodnced  by  it  indicates  the  time  for  its  removal,  when  nsnally 
the  dentin  will  be  fonnd  to  be  insensitive.  There  arc  instances,  how- 
ever, when  no  a[)parent  effect  is  prodnced,  which  can  oidy  be  satisfac- 
torily explained  on  the  ground  that  the  vital  resistance  of  tlie  tissue  is 
sufficient  to  overcome  the  coagulative  power  of  the  zinc  salt. 

In  general,  zinc  chlorid  must  be  regarded  as  an  entirely  safe  agent 
if  used  with  discretion.  It  is  more  aj)plicable  to  shallow  cavities  which 
are  so  situated,  or  are  of  such  form,  as  to  rccpiirc  much  formative  cutting 
at  the  margins  of  the  cavities,  as  in  buccal  and  labial  surfaces  and  in  the 
very  superficial  cavities  of  incisors  and  bicuspids.  A  warning,  however, 
should  be  presented  that  as  the  pulp  c(n"nua  of  incisors  frequently  pro- 
ject near  the  surface,  j)articularly  in  the  young  subject,  considerable  care 
is  here  recpiired  in  any  but  shallow  cavities  of  decay.  If  it  were  used 
in  excess  and  its  action  extended  there  would  always  be  danger,  as 
its  energies  would  not  cease  tnitil  the  affinities  of  the  whole  amoinit 
were  satisfied.  In  deep  cavities  the  effi^ct,  particularly  in  soft  teeth, 
would  eventuate  in  the  ultimate  devitalization  of  the  pulp.  It  fol- 
lows, therefore,  that  it  would  be  improper  to  seal  up  any  quantity  of 
this  substance  in  a  cavity. 

The  action  of  zinc  chlorid  is  terminated  when  the  excess  is  removed 
and  the  cavity  irrigated  with  water.  The  affinity  it  has  for  water 
quickly  removes  the  excess  and  soon  deprives  the  tissue  of  the  remain- 
ing portion. 

When  cavities  are  deep  and  it  is  found  necessary  to  resort  to  this 
agent  the  surface  of  the  deeper  parts  should  be  protected  by  an  insoluble 
coating,  after  which  the  margins,  where  the  sensitivity  is  acute,  may  be 
acted  upon  without  detriment.  Here  it  is  requisite  to  remove  the  deep 
caries,  desiccate  the  surface  and  make  a  coating  with  a  varnish.  For 
this  purpose  red  gutta-percha  rubbed  in  chloroform  is  applicable,  since 
it  may  be  deftly  applied  to  any  given  part  and  when  the  chloroform  has 
escaped  is  protective. 

To  properly  apply  zinc  chlorid  it  is  highly  important  to  isolate  the 
tooth  by  means  of  rubber  dam  to  protect  the  gum  and  to  prevent  the 
entrance  of  moisture.  Its  affinities  for  water  are  so  great  that  even 
the  vapor  of  the  mouth  dilutes  it  so  much  as  to  lessen  its  power.     The 


DENTINAL  ANESTHESIA   BY  CHEMICAL  AGENTS  171 

form  in  which  it  is  best  to  employ  it  is  the  saturated  deliquesced  salt, 
which  is  taken  from  a  bottle  containing  the  salt  in  excess.  The  fluid 
is  introduced  on  a  pledget  of  cotton  and  is  permitted  to  remain  until 
the  pain  occasioned  by  it  has  ceased.  It  will  be  found  that  there  are 
two  periods  of  pain  :  the  first  from  its  irritation  of  the  fibrils  in  the 
bottom  layer  of  the  caries,  and  then  again  when  it  has  reached  the 
zone  of  exalted  dentin  a  little  beneath  this  ultimate  layer  of  decay. 
It  follows,  if  the  caries  has  all  been  previously  removed  and  the 
sensitive  tissue  interdicts  further  cutting,  that  but  one  period  of  pain 
is  encountered.  The  cutting  should  therefore  be  deferred  until  after 
the  second  period  of  pain  has  passed.  The  disregard  of  this  considera- 
tion has  sometimes  cast  discredit  upon  the  efficiency  of  this  sovereign 
remedy. 

It  is  requisite  that  the  chlorid  be  chemically  pure,  and  the  fused 
form  is  preferable  to  the  crystals  of  the  shops. 

The  PAix  attending  the  application  is  sometimes  extreme  for  a  mo- 
ment. This  can  be  moderated  by  air-drying  the  cavity  and  dressing  it 
with  carbolic  acid,  which  does  not  seem  to  prevent  the  action  of  the 
chlorid. 

To  avoid  the  loss  of  time  which  may  be  occasioned  by  the  slow 
action  it  is  advisable,  after  securing  the  dam  at  the  neck  of  the  tooth 
by  a  ligature,  to  very  tightly  tie  the  free  portion  of  the  rubber  a  short 
distance  from  the  tooth  with  a  strong  ligature,  and  after  cutting  away 
the  excess  of  rubber  some  other  service  may  be  rendered.  AVhen  the 
pain  has  ceased  the  case  may  be  proceeded  with,  or  the  excess  of  chlorid 
may  be  thoroughly  washed  out  and  the  cavity  temporarily  closed  until 
a  subsequent  time. 

Another  method  of  securing  the  action  of  zinc  chlorid  is  to  make  a 
paste  of  zinc  oxychlorid  and  fill  the  cavity  with  it.  Even  after  crys- 
tallization of  the  paste  takes  place  it  contains  a  slight  excess  of  the 
chlorid,  which  slowly  acts  upon  the  hypersensitive  tissue.  This  method, 
however,  is  not  adapted  to  deep  cavities,  and  care  must  be  exercised  con- 
cerning its  use  in  teeth  of  inferior  grade. 

Zinc  chlorid  is  an  extremely  valuable  remedy  when  the  previously 
described  agents  prove  insufficient  or  are  not  indicated. 

Conditions  lohich  render  Zinc  Chlorid  inadmissible. — It  has  been 
stated  that  the  chief  danger  of  its  use  consists  in  the  liability  of  the 
coagulant  and  escharotic  action  reaching  the  pulp  in  deep  cavities. 
This  danger  is  further  enhanced  when  the  teeth  are  soft,  as  in  this  con- 
dition the  penetration  is  liable  to  be  greater  than  would  be  the  case  with 
dense  dentin.  The  same  caution  must  be  observed  when  the  structure 
is  incomplete,  as  it  is  in  the  teeth  of  young  subjects.  Even  here,  as 
extreme  sensitiveness  is  always   found  at  the  peripheral  limits  of  the 


172  PRELIMINARY  PRFPARATfOy   OF  CAVITIKS,   ETC. 

tubule?:,  it  is  not  difticull  to  limit  the  action  to  this  |)art  hy  tlio  means 
abov(>  j)oini*'(l  out  if  care  he  taken  in  the  rc(|nin(l  ]iroc(Mhn'('s. 

The  Acids. — Chromic  and  nitric  acids  are  ot'  service  in  extremely 
shallow  cavities  of  very  high  sensitivity.  The  former  acts  by  coagula- 
tion of  the  organic  elements  of  the  dentin  and  the  latter  l)y  decomposi- 
tion and  solution.  To  apply  these  the  adjacent  tissues  require  to  be 
protected.  Each  should  be  carried  in  small  quantity  upon  a  gold 
probe. 

Silver  nitrate  is  applicable  for  reducing  the  sensitivity  of  dentin 
after  the  removal  of  superfit;ial  caries  or  when  by  abrasion  or  by  erosion 
the  exposed  tissue  is  intolerably  sensitive.  It  is,  however,  only  to  be 
used  in  the  back  of  the  month,  on  account  of  the  discoloration  "which  it 
produces. 

Antimony  chlorid  is  applicable  only  to  cases  of  exposed  cemeu- 
tum,  where  it  is  claimed  that  it  is  equally  as  efficient  as  silver  nitrate, 
and  has  not  the  objection  of  discoloring  the  tissue. 

General   Anesthesia. 

AVhile  some  reluctance  should  exist  as  to  the  propriety  of  inducing 
general  anesthesia,  it  sometimes  becomes  necessary  to  resort  to  this 
means  of  alleviation.  Necessity  for  this  election  arises  where  the  sen- 
sitivity is  extreme,  when  the  previous  remedies  have  been  inefficient, 
and  when  from    the    nature  of  the  case  zinc  chlorid  is    inadmissible. 

The  subjects  should  generally  be  adult  persons  of  intelligence,  who 
possess  moral  force  and,  having  confidence  in  their  adviser,  are  capable 
of  giving  the  requisite  indications  of  the  j)rogress  of  the  anesthetic 
influences. 

Sulfuric  ether  is  the  most  suitable  anesthetic  to  be  employed,  and 
the  operative  procedures  should  be  performed  in  the  first  stage,  that 
of  peripheral  anesthesia.  At  this  period,  which  is  before  the  stage 
of  excitement  commences,  dentin  may  be  cut  without  the  slightest 
pain  being  felt.  This  is  an  important  consideration,  since  if  the  ad- 
ministration is  continued  into  the  period  of  excitement  nothing  can  be 
done,  and  if  it  is  conducted  to  a  full  degree  the  patient  is  not  manage- 
able. Also  the  subsequent  depression  is  to  be  avoided.  AVhile  general 
anesthesia  in  the  first  stages  is  available  for  the  relief  of  dentinal  sensi- 
tivity, it  is  found,  on  the  contrary,  w'hen  resorted  to  for  the  removal  of 
the  pulp,  as  may  occasionally  be  required  in  the  most  severe  cases  of 
congestion,  that  nothing  short  of  profound  anesthesia  will  suffice. 

When  the  first  strif/e  is  reached,  the  patient  being  conscious  and  able 
to  reply  to  questions,  the  cutting  is  commenced  ;  as  the  pain  returns  a 
few  more  inhalations  are  given,  when  another  part  of  the  cutting  may 
be  proceeded  with.     This  may  be  repeated  until  the   cavity  is  formed. 


GENERAL  ANESTHESIA. 


173 


Fig.  114. 


The  cutting-  should  be  quickly  and  deftly  conducted.  The  amount  of 
ether  administered  is  far  less  than  is  required  to  induce  full  anesthesia, 
and  the  patient  suffers  far  less  depression  than  if  the  operation  were 
performed  without  this  means.  There  is  also  no  danger  of  shock,  since 
the  patient  is,  or  should  be,  intelligently  concerned  in  the  progress  of  the 
case.  If  the  condition  were  carried  into  the  second  stage,  when  excite- 
ment exists  and  alarm  is  aroused  in  addition  to  the  operative  interfer- 
ence, there  is  liability  to  shock,  which,  being  due  to  a  profound  impres- 
sion on  the  nervous  system,  is  not  liable  to  occur  when  the  patient 
concurs  in  all  the  steps  of  the  procedure. 

The  time  required  to  bring  about  a  sufficient  degree  of  dentinal 
anesthesia  frequently  is  less  than  two  minutes.  The  ether  should  be 
pure  and  should  be  given  with  a  free  supply  of  air  mixed  with  the 
vapor.  The  ordinary  custom  of  using  the  towel  to  envelop  the  face  is 
questionable,  since  this  method  does  not  permit  enough  air  to  accompany 
the  ether  vapor. 

An  invaluable  inhaler  for  this  purpose  is  the  one  invented  by  Dr. 
Allis  (Fig.  114).  This  consists  of  an  oval 
frame  composed  of  a  series  of  wires  through 
which  passes  back  and  forth  a  continuous 
band  of  muslin.  The  layers  of  muslin 
are  near  each  other,  and  still  so  far  apart 
as  to  permit  the  free  passage  of  the  at- 
mosphere. The  correct  manner  is  to 
continuously  drop  the  ether  in  small 
quantity  upon  the  muslin  to  maintain  it 
at  an  even  degree  of  partial  saturation. 

This  appliance  is  one  of  value  to  the 
dental  operator,  as  by  it  the  anesthetic 
state  can  be  more  quietly  brought  about 
with  less  of  the  characteristic  disturb- 
ances Avhich  attend  the  usual  modes  of  applying  sulfuric  ether. 

The  use  of  chloroform  for  the  purpose  under  discussion  is  wholly 
inadmissible. 

The  mechanical  means  consist  in  the  use  of  temporary  fillings, 
which  may  be  either  metallic  or  non-metallic.  The  metallic  act  by 
inducing,  in  consequence  of  the  slight  irritation  of  thermal  conductivity, 
a  consolidation  of  the  subjacent  dentin,  which  in  time  obliterates  the 
tubules.  The  non-metallic  act  simply  as  a  protective  covering  to  the 
denuded  dentin.  Their  action  hence  is  more  tardy  than  that  which 
follows  the  use  of  the  former. 

The  metallic  stoppings  for  this  purpose  may  be  composed  of  either 
tin  foil  or  amalgam.     Each  of  these  requires  cavities  of  reasonably  good 


The  Allis  inhaler. 


174  PRELIMINAPxY   PREPARATION   OF  CAVPriES,   ETC. 

ivti-ntivoness,  tlu'ivforc  they  are  not  applicable  tu  .shallow  cavities  Oi 
unsuitable  form. 

The  non-mctallir  may  he  either  j^utta-percha,  zinc  ph()s])hate,  or  zinc 
oxyehlorid.  The  two  hitter  arc  tlic  most  desirable,  as  they  adhere 
to  anv  well-dried  cavity,  and  having-  some  irritating  influence  on 
the  tissues  tend  to  induce  structural  consolidation  in  addition  to  their 
])roteetive  action.  They  have,  however,  the  disadvantatre  of  sut!'crin<j^ 
loss  bv  chemical  solution,  and  unless  kej)t  under  close  observation  are 
delusive  and  in  many  instances  are  a  deceptive  means  of  preventing;  the 
recurrence  of  decav.  In  the  em]doyment  of  these  substances  <lue  care 
should  be  exercised  concerning  the  proximity  of  the  pulp,  in  which  cases 
the  previously  indicated  means  of  shielding  the  pulp  walls  should  be 
pursued. 

The  chief  disqualilication  of  gutta-percha  is  its  lack  of  resistance  to 
attrition,  and  when  in  positions  shielded  from  wear  it  may  be  attacked 
by  low  forms  of  bacterial  life,  which  disintegrate  it. 

Mechanical  protection  of  cavities  is  most  applicable  to  teeth  of  a  low 
grade  of  structure  and  for  young  children  who  may  not  have  the  ability 
to  tolerate  the  mor(>  active  means  needed  to  reduce  dentinal  sensitivity. 
For  these  cases  gutta-percha  stoppings  when  carefully  introduced  are  a 
great  boon,  since  they  ])rotect  the  tissues  during  the  period  of  completion 
and  consolidation  of  the  dentin. 


CHAPTER   VII. 

PREPARATION  OF  CAVITIES— OPENING  THE  CAVITY— RE- 
MOVING THE  DECAY— SHAPING  THE  CAVITY— CLASSI- 
FICATION OF  CAVITIES. 

By   S.   H.   Guilford,   A.  M.,  D.  D.  S.,  Ph.  D. 


General  Considerations. — The  importance  of  the  proper  preparation 
of  a  cavity  for  the  insertion  of  a  filling  can  scarcely  be  overestimated. 
Upon  its  being  well  done  the  success  of  the  completed  operation  largely 
depends.  As  many  fillings  fail  from  lack  of  thoroughness  in  the  pre- 
paration of  the  cavity  as  from  any  other  cause. 

The  operator  should  not  be  actuated  by  haste,  but  should  be  deliber- 
ate, careful,  and  painstaking.  Each  stage  of  the  operation  should  be 
thoroughly  performed  in  order  that  when  completed  the  cavity  may  be 
in  the  best  possible  condition  for  the  reception  and  retention  of  the  filling. 

The  operation  is  naturally  divided  into  five  stages : 

1.  Opening  the  Cavity. 

2.  Establishing  the  Cavity  Outlines. 

3.  Removing  the  Decay. 

4.  Shaping  the  Cavity. 

5.  Perfecting  the  Enamel  Margins. 

1.  Opening  the  Cavity. 

Every  cavity  to  be  excavated  must  first  be  opened,  so  that  it  may  be 
approached  and  operated  upon  at  all  points.  The  particular  manner  of 
doing  this  will  have  to  be  determined  by  the  extent  of  the  decay  and  its 
position,  but  in  all  cases  the  opening  must  be  as  full  and  free  as  the 
conditions  will  permit. 

The  accessibility  of  the  cavity  will  depend  upon  its  location.  Upon 
the  three  exposed  surfaces  of  a  tooth  crown  (occlusal,  lingual,  and  labial 
or  buccal)  access  to  a  cavity  is  usually  easy,  but  upon  the  unexposed 
surfaces  (approximal)  access  can  only  be  had  after  the  teeth  have  been 
pressed  apart.  For  methods  of  securing  temporary  separation  of  the 
teeth  see  Chapter  V. 

A  cavity  upon  an  exposed  surface,  if  small,  can  usually  best  be 
opened  by  the  use  of  some  form  of  engine  bur.  A  few  sizes  each  of 
the   forms    known    as    "fissure,"    "inverted-cone,"   and    "round"   (or 

175 


17(> 


PREPARATION  OF  CAVITIES. 


"rose-head")  arc  shown  in  Figs.  115-117.  A  spear-pointed  drill 
is  sometimes  used,  Ixit  is  less  serviceable  on  account  of  its  tendency 
to  be  eanght  or  broken  in  the  irregnhirities  of  the  cavity  orifice.  A 
modified  form  of  fissure  bur  has  found  nuu-h  favor  in  the  opening  of 
small  cavities  on  exposed  surfaces.      It   is  made  from  an  ordinary  bur 


Fu;.  115. 


Fi(i.  116. 


Fk;.  117. 


Fissurt"  burs. 


luvLTtfil-cuiie  t'ur- 


from  which  the  head  has  been  broken,  by  cutting  spiral  blades  on  the 
tapering  neck  of  the  shank.  Being  pointed,  round,  and  tapering  it 
easily  effects  an  entrance  into  the  cavity  and  enlarges  the  orifice  grad- 
ually and  symmetrically.     It  is  shown  in  Fig.  119. 

In  cavities  of  larger  size,  where  decay  lias  made  more  progress,  the 
overhanging  walls  of  enamel  can  best  be  broken  down  by  chisels  of 
suitable  size  and  form.  AVhere  a  straight  cliisel  can  be  employed  it 
will  be  found  most  efficient,  but  in  positions  difficult  of  access  one 
having  a  slight  curve  or  angle  may  need  to  be  employed.  Figs.  120  and 
121  represent   both   forms  as  well  as  the  sizes  usually  preferred.     The 


Fig.  118. 


Fig.  119. 


Fig.  120. 


Fig.  121. 


^ 


J  Li  Li   L 

Cross-cut  burs. 


Modified  fissure  bur 
wiUi  taperiug  point. 


itraiglit  chisels. 


Curved  chisels. 


width  of  the  blade  may  vary  from  one-sixteenth  to  one-cightli  of  an  inch, 
but  wider  ones  than  these  will  seldom  be  required. 

A  chisel  may  be  used  with  either  hand  ])ressure  or  mallet  force.  If 
the  former,  great  care  must  be  exercised  to  prevent  its  slipping  and 
causijig  pain  or  possible  injury.  The  best  safeguard  in  its  use  is  to 
place  the  thumb  of  the  right  hand  on  the  tooth  being  operated  upon  or 
some  adjoining  one  and  use  it  as  a  fulcrum  or  pivot  upon  which  the. 


REMOVING   THE  DECAY. 


177 


Fig.  122. 


instrument  may  move  in  a  curve.  By  this  means  the  motion  of  the 
chisel  is  regulated  and  controlled  and  all  danger  of  slipping  avoided. 
It  will  sometimes  be  of  advantage  to  roughly  pack  the  interior  of  the 
cavity  with  cotton  or  spunk  to  receive  the  impact  of  the  instrument 
should  the  chisel  accidentally  be  forced  to  the  bottom  of  the  cavity. 

The  better  plan,  however,  in  most  cases,  is  to  employ  mallet  force 
for  the  cleavage  of  enamel  unsupported  by  dentin.  By  holding  the 
chisel  between  the  thumb  and  three  fingers  of  the  left  hand  and  resting 
the  little  finger  of  the  -same  hand  on  an  adjacent  tooth  for  steadiness,  a 
smart  but  light  blow  of  a  mallet  in  the  right  hand  upon  the  end  of  the 
chisel  will  easily  and  painlessly  cleave  oif  portions  of  the  enamel. 

In  opening  cavities  of  small  extent  or  limited  depth  upon  approxi- 
mal  surfaces  a  round  or  inverted-cone  bur  will  best 
serve  the  purpose,  but  where  caries  is  more  exten- 
sive and  the  surrounding  enamel  is  unsupported  by 
dentin  the  orifice  of  the  cavity  can  be  more  advan- 
tageously enlarged  by  means  of  a  delicate  chisel 
(shown  in  Fig.  122)  the  blade  of  which  is  bent  at  a 
slight  angle  to  the  shank  and  all  three  of  the  edges 
of  which  are  bevelled  to  convert  them  into  cutting 
edges.  This  instrument  will  be  found  especially 
useful  in  opening  cavities  of  medium  or  larger  size 
on  the  approximal  surfaces  of  the  incisors,  the  point 
doing  the  cleaving  and  the  side  edges  being  used  to 
smooth  the  enamel  margins. 

After  the  orifice  of  the  cavity  has  been  sufficiently 
enlarged  to  aiford  a  full  view  of  its  interior  the  next 
stage  of  the  operation  is  entered  upon — 

2.  Establishing  the  Cavity  Outlines. 

In  all  cases,  and  especially  for  those  on  approximal  surfaces,  it  is 
necessary  to  extend  the  boundaries  of  cavities  not  only  to  include  all 
decayed  or  injured  tooth  structure,  but  also  all  such  healthy  tooth  tissue 
as  may  be  required  in  order  to  bring  the  outlines  of  the  cavity  to  such 
points  as  will  establish  relative  immunity  from  future  decay. 

To  this  end,  in  cavities  upon  the  approximal  surfaces  of  biscuspids 
and  molars,  if  of  considerable  size,  the  buccal  wall  should  be  extended 
to  the  approximo-buccal  angle  of  the  tooth ;  the  lingual  wall  to  the 
approximo-lingual  angle,  and  the  cervical  or  gingival  wall  to  a  point 
beneath  the  free  margin  of  the  gum.  Thus  extended,  the  buccal  and 
lingual  walls  will  be  in  such  position  as  to  be  kept  clean  and  free  from 
food  deposits,  and  consequently  from  decay.  The  gingival  wall,  extended 
beneath  the  gum  margin,  is  protected  and  immunized  by  the  overlapping 
gum  tissue. 

12 


Delicate  three-sided 
chisel,  useful  for 
opening  cavities  on 
approximal  sur- 
faces. 


178 


PUKPAUATIOX   OF  CAVITIKR. 


Cavities  on  tlio  appr(>xim:il  surfaces  of  tlie  incisors  and  canines  sliould 
in  like  manner  l>e  extended  to  include  the  entire  area  of  possible  future 
decay,  l)nt  tiiey  do  not  need  to  he  extended  so  far  lahially  as  to  make 
the  p)ld  conspicuous. 

'i'he  liiiLiual  niartrinsof  these  cavities  may  he  freely  extended  linjjually, 
both  to  in-ure  necessary  streiii^th  and  to  atfitrd  room  for  ajtproaeh  in  the 
act  <»f  HlliiiLT. 

In  stndvintr  the  size  and  form  necessary  for  each  cavity  to  jiossess,  a 
mental    ])icture    should   he   drawn   and   the  cavity  shapecl   in   accordance 


•ith  it. 


3.  Removing  the  Decay. 


The  character  or  consistence  of  the  carious  structure  has  much  to 
do  witli  the  method  and  means  employed  for  its  removal.  If  it  be  of 
the  i^cmi-clastic  or  leathery  variety  so  often  found  in  the  teeth  of  y(»un(r 
persons,  it  can  be  most  easily  removed  by  means  of  npoon-xliaped  or 
round-bkided  EXCAVATORS,  which  being;  oval  or  circular  in  ed^v  out- 
line and  free  from  marginal  angles,  will  lift  and  separate  the  layers 
without  danger  of  injuring  the  underlying  healthy  dentin  and  with  the 
infliction  of  a  minimum  amount  of  pain.  Fig.  1G7  illustrates  this  kind 
of  instrument  in  some  of  its  forms,  selected  from  the  Darby-Perry  set. 

In  the  cJarJ:,  hard  variety  of  caries,  as  also  in  the  white,  chcdky 
variety,  the  different  forms  of  burs  and  excavators  will"  be  found  best 
suited  for  the  purpose. 

In  the  removal  of  caries  care  should  be  exercised  to  inflict  as  little 
pain  upon  the  patient  as  possible.  To  this  end,  in  cavities  of  con- 
siderable extent,  it  is  best,  after  the  orifice  has  been  sufficiently  enlarged, 
to  make  a  sweeping  cut  with  an  excavator  around  the  cavity  just  below 

P>;.  T23. 


"  0  u  i  f  11  ii  n  n  r  w  1 


Excas-ators. 


the  enamel  line,  thus  freeing  the  decayed  portion  at  that  point.  Follow- 
ing this  the  remaining  portion  of  carious  dentin  should  be  removed  by 
placing  the  blade  of  the  excavator  near  the  bottom  of  the  cavity  and 


REMOVING    THE  DECAY.  179 

making  draw-cuts  toward  the  orifice.  To  cut  in  the  reverse  direction 
would  produce  uncorafortable  pressure  upon  the  most  tender  portion  of 
the  cavity,  and  possibly,  by  inadvertence,  expose  and  wound  the  pulp. 
When  burs  are  employed  for  the  removal  of  caries  it  is  safest  to  use 
only  those  more  or  less  rounded  on  their  circumference,  such  as  the  round 
■  or  oval  forms,  for  they  more  nearly  conform  to  the  natural  outline  of  the 
cavity,  leave  no  angular  grooves  in  the  dentin,  and  are  not  so  likely  to 
injure  the  subjacent  healthy  dentin. 

The  varieties  of  bur  known  as  the  inverted-cone  and  wheel,  while  very 
useful  for  opening  cavities,  should  not  be  used  for  the  removal  of  caries 
in  deep  cavities,  because  of  the  irregularities  of  surface  which  their 
peripheral  angles  produce. 

Rapidly  revolving  burs  in  an  engine  handpiece  are  very  apt  to  cause 
pain  by  the  development  of  frictional  heat.  This  may  largely  be  pre- 
vented by  lifting  the  bur  at  short  intervals  and  allowing  it  to  run  free 
for  a  moment,  which  will  prevent  overheating  the  tooth  and  thus  avoid 
unnecessary  pain. 

Thorough  excavation  of  the  cavity  and  the  removal  of  all  carious 
dentin  is  absolutely  essential  to  success.  To  allow  any  portion  of  it  to 
remain  and  trust  to  the  employment  of  germicides  for  its  sterilization 
is  running  the  risk  of  failure,  for  we  can  never  be  entirely  sure  of 
disinfection.  Besides  this,  there  is  no  good  reason  for  allowing  it  to 
remain . 

By  carious  dentin  is  meant  the  remains  or  debris  of  the  action  of 
caries, — a  product  resulting  from  this  disintegrating  action  upon  both 
the  organic  and  inorganic  constituents  of  dentin.  In  nearly  all  cavi- 
ties we  find  tivo  varieties  of  altered  tissue.  That  nearest  the  surface  is 
a  mass  of  thoroughly  disorganized  and  usually  decomposed  matter  filled 
with  micro-organisms.  Beneath  this  and  lying  next  to  the  healthy  den- 
tin there  is  a  zone  or  layer  from  which  the  calcium  salts  have  been  re- 
moved by  the  acid  solvent,  but  which  still  retains  its  original  form  and 
vitality.  This  layer  of  decalcified  dentin  may  be  allowed  to  remain, 
especially  in  the  bottom  of  a  cavity,  as  it  serves  to  protect  the  subjacent 
tissue  from  thermal  shock,  but  as  a  precautionary  measure  it  should  be 
treated  to  an  alkaline  application  or  some  germicide  such  as  carbolic  acid, 
mercury  bichlorid,  formalin  (10  per  cent,  aqueous  solution),  or  oil  of 
cinnamon,  before  the  insertion  of  the  filling. 

Occasionally  caries  will  be  found  to  be  self -limited .  In  such 
cases,  through  some  unexplained  change  of  conditions,  the  progress 
of  caries  has  been  checked  and  the  layer  of  decalcified  dentin  re- 
stored to  its  previous  normal  condition.  AVhere  this  has  taken  place 
the  restored  tissue  is  usually  of  a  darker  color  than  ordinary  dentin, 
and  on  this  account  may  be  mistaken  for  carious  dentin  and  removed. 


180  PREPARATION  OF  CAVITIES. 

It  is,  however,  easily  distinguished  irom  ciiries  hy  its  hanhiess,  and 
shouhl  in  no  case  be  removed  exeept  from  the  sides  of  a  eavity,  and 
then  only  when  its  dark  color  sho\vin<;  throu;;h  the  walls  would  prevent 
the  cavity,  after  being  filled,  from  having  that  clear  and  clean  appear- 
ance which  it  should  possess. 

"With  some  practitioners  it  is  the  custom  to  prej)are  a  cavity  f //•//, 
because  in  this  way  the  operation  is  more  rapid  and  usually  less  ])aiuful. 
In  such  case  the  rubber  dam  is  applied  first  of  all  and  the  operations  of 
opening,  cleansing,  and  shaping  the  cavity  are  all  performed  without 
the  presence  of  moisture.  He])eated  applications  of  warm  air  from  a 
syringe,  at  intervals  (hiring  the  operation,  desiccate  the  dentin  and  di- 
minish its  j)o\ver  of  sensation.  Others,  in  order  to  avoid  the  unpleasant- 
ness to  the  patient  of  having  the  dam  in  position  for  so  long  a  time, 
prepare  the  cavity  roughly  in  the  presence  of  moisture,  then  apply  the 
dam,  dry  the  tooth  thoroughly,  and  finish  the  operation. 

Whichever  plan  is  adopted  it  is  absolutely  necessary,  in  all  cases,  to 
finish  the  preparation  with  the  dam  on  and  the  tooth  dry,  for  it  is  only 
after  a  tooth  has  been  deprived  of  its  moisture  that  we  are  able  to 
decide  whether  all  the  niceties  of  })reparation  have  been  successfully 
carried  out.  Certain  marginal  and  structural  defects  that  are  not 
noticeable  w^hile  the  tooth  is  moist  are  plainly  revealed  after  it  has  been 
dried. 

4.  Shaping  the  Cavity. 

This  is  one  of  the  most  important  of  all  operations  associated  with 
the  stopping  of  a  cavity,  for  according  as  it  is  properly  or  improperly 
performed  success  or  failure  will  result.  Too  much  stress  cannot  be 
laid  upon  its  importance,  nor  too  great  care  be  exercised  in  its  accom- 
plishment. 

Inasmuch  as  a  filling  is  retained  in  place  inecJuinicaUij  it  follows  that 
the  cavitv  must  be  of  such  shape  as  to  secure  retention.  To  this  end  it 
should  be  larger  within  (at  least  at  certain  points)  than  at  the  orifice. 
An  exception  to  this  rule  lies  in  cavities  where  the  depth  is  greater  than 
the  diameter.  In  cavities  of  this  character  parallel  walls  will  suffice, 
because  lateral-surface  contact  is  so  great  in  proportion  to  the  mass  to  be 
held  in  place  that  displacement  could  not  occur.  In  larger  cavities  of 
moderate  depth,  however,  the  reverse  is  the  case,  and  they  will  require 
the  assistance  of  internal  enlargement  for  the  retention  of  the  filling.  To 
govern  each  of  the  conditions  two  rules  may  be  formulated  : 

1.  When  the  depth  of  the  cavity  is  greater  tlian  the  diameter  of  the 
orifice,  parallel  lateral  walls  will  prove  retentive. 

2.  When  the  diameter  of  the  orifice  is  greater  than  the  depth  of  the 
cavitv,  the  latter  will  have  to  be  somewhat  enlarged  internally  to  retain 
the  filling. 


SHAPING   THE  CAVITY.  181 

Examples  of  the  first  class  are  found  in  the  narrow  but  rather  deep 
cavities  which  occur  on  the  lingual  surfaces  of  the  upper  incisors 
near  the  cervix  ;  in  the  pit  cavities  on  the  buccal  surfaces  of  molars ; 
and  in  the  small  cavities  found  on  either  side  of  the  enamel  ridge  on 
the  occlusal  surfaces  of  the  lower  first  bicuspids. 

Examples  of  the  second  class  are  found  in  numberless  places  on  any 
of  the  crown  surfaces. 

In  some  cases  cavities  will  be  found  of  such  form  that  when  caries 
has  been  removed  they  will  have  a  naturally  retentive  shape,  but  in 
the  great  majority  of  cases  more  or  less  sound  tissue  will  have  to  be 
removed  in  order  to  give  them  the  required  form.  To  give  a  cavity  a 
retentive  form  it  is  not  necessary  that  its  interior  be  enlarged  throughout 
its  whole  extent,  but  it  must  be  larger  at  two  or  more  points,  and  these 
points  must  be  opposite  one  another.  Frequently  it  will  be  easier  to 
enlarge  the  cavity  at  all  points,  and  to  this  no  objection  can  be  urged 
provided  too  much  sound  tissue  be  not  removed  or  the  pulp  be  not  too 
nearly  approached.  Too  great  enlargement  tends  to  weaken  the  cavity 
walls  and  therefore  should  be  guarded  against. 

In  shaping  the  cavity  internally  instruments  should  be  employed 
that  will  leave  the  surface  free  from  angles.  Excavators  for  this  pur- 
pose should  have  curved  edges,  and  burs  should  be  of  a  round  or  oval 
form. 

If  grooves  are  required  they  should  be  made  neither  deep  nor  too 
near  to  the  enamel,  to  avoid  weakening  the  walls.  At  the  cervical 
margins  of  cavities  grooves  and  starting  pits  should  be  avoided  when- 
ever possible,  for  they  weaken  the  portion  of  the  cavity  which  is  sub- 
jected to  the  greatest  strain  in  the  introduction  of  the  filling,  both 
mechanically  and  by  cutting  off  the  nutrient  supply  to  the  cervical 
margin,  which  tends  to  alter  the  resistive  character  of  that  portion  of 
the  tooth  structure  by  devitalizing  it. 

For  the  same  reasons  deep  grooves  or  undercuts  should  not  be  made 
near  the  incisal  or  occlusal  surfaces,  for  the  strain  of  mastication  will  be 
liable  to  result  in  fracture  of  the  wall  if  it  is  thus  unduly  weakened. 

In  the  process  of  shaping  the  cavity  internally  the  enamel  margins 
will  naturally  be  assuming  their  proper  form,  but  the  final  part  of  the 
preparation  should  consist  in  giving  these  frail  portals  of  the  cavity 
very  careful  and  minute  attention. 

The  permanency  of  a  filling  will  depend  largely  upon  the  strength  of 
the  enamel  walls  and  their  proper  preparation.  The  enamel  cap  of  a  tooth 
when  intact  is  exceedingly  strong  and  capable  of  resisting  great  strain, 
but  when  its  continuity  has  been  broken  by  caries  and  it  is  left  unsup- 
ported by  dentin  it  is  very  weak  and  brittle.  This  is  readily  understood 
when  we  remember  that  enamel  is  composed  of  an  aggregation  of  enamel 


182 


PREPARATION  OF  CAVITIES. 


rods  or  prisms  in  close  juxta}K>sition,  slightly  joined  together  by  a 
cementing  substance,  with  their  greater  diameters  perpendicular  to  the 
plane  of  the  surface  of  dentin  upon  which  they  rest.  AVhcn  continuous, 
these  rods  mutually  support  one  another  and  are  thus  capable  of  resisting 
great  strain  ;  l)ut  Avhen  a  lesion  has  occurred  they  lose  support  on  the 
adjoining  side  and  hence  are  easily  separated  in  the  direction  of  their 
lentrth.  Fig.  124  (after  Black')  shows  this  condition  perfectly.  A  de- 
tached section  of  enamel  prisms  is  represented  at  a,  and  at  b  is  shown  a 
portion  about  being  separated  by  a  chisel. 

Fig.  124. 


Showing  enamel  stmcture. 


This  will  explain  why  enamel  unsupported  by  dentin  should  not  be 
allowed  to  form  the  margin  of  a  cavity,  for  it  will  probably  either  be 
fractured  while  the  filling  is  being  introduced  or  afterward  in  mastication. 

On  all  convex  surfaces  of  a  tooth  the  enamel  rods  radiate  outwardly, 
and  by  forming  the  margins  of  a  cavity  on  these  lines  it  will  have  a 
slightly  flaring  or  trumpet-shaped  orifice,  which  will  not  only  afford  the 
greatest  strength  but  will  admit  of  a  better  finish  being  given  to  the  edges 
of  the  filling.  In  many  cases  it  will  be  necessary  to  give  the  margins  of 
a  cavity  more  of  an  outward  bevel  than  would  be  obtained  by  simply 
following  the  cleavage  lines  of  the  enamel  rods.  This  can  be  secured 
by  cutting  away  the  (juter  ends  of  the  enamel  rods  in  an  oblique  direc- 
tion as  shown  at  c  in  Fig.  124.  ]Vo  weakening  of  the  border  will  result 
in  such  cases,  inasmuch  as  the  shorter  rods  will  still  rest  upon  the 
dentin.  If,  however,  the  rods  were  cut  so  as  to  leave  only  their  outer 
ends  in  place,  as  shown  at  (/,  they  would  have  no  substantial  support, 
and  would  be  liable  to  be  crushed  during  filling  or  afterward.  All 
cavity  margins  should  have  the  outward  bevel  to  a  greater  or  less 
extent  in  order  to  secure  the  best  and  most  permanent  results. 

In  cavities  upon  depressed  or  concave  surfaces  of  teeth  it  would  not 

'  Dental  C'omnos,  vol.  xxxiii.,  ji.  441. 


PERFECTING   THE  ENAMEL  MARGINS. 


183 


Fig.  125. 

B     B 


Cross-sectiou  of  a  bi- 
cuspid showing-  treat- 
ment of  enamel  in 
the  sulcus. 


do  to  have  the  enamel  margins  formed  on  the  lines  of  enamel  cleavage 
for  this  would  make  the  margin  of  the  orifice  the  most  contracted  por- 
tion and  result  in  frail  marginal  edges.  Fig.  125, 
representing  a  cross-section  of  a  bicuspid  tooth  with 
a  cavity  in  the  sulcus,  will  illustrate  this  point :  a 
shows  the  cavity  orifice  prepared  on  the  lines  of 
enamel  cleavage,  and  b  the  dressing  across  the  outer 
edges  of  enamel  required  to  give  the  necessary 
strength. 

It  may  therefore  be  laid  down  as  a  rule  that  to 
secure  the  best  results   the   line  of  the  enamel  wall 
from  within  outward  should  form  tcith  the  surface  of  the  tooth  at  this- 
point  an  obtuse  angle. 

5.  Perfecting  the  Enamel  Margins. 

Beside  the  proper  shaping  of  a  cavity  margin  it  should  be  made 
as  smooth  as  possible.  In  accessible  cavities  upon  exposed  surfaces  of 
teeth  the  final  marginal  smoothing  or  finish  can  best  be  eifected  bv  the 
use  of  a  bur  shaped  somewhat  like  a  fissure  bur,  but  having  a  rounded 
end  and  being  simply  file-cut  upon  its  surface  instead  of  being  bladed. 
Such  a  one  is  shown  in  Fig.  126.  Its  sides  being  parallel,  no  rounding 
of  the  cavity  margins  can  occur  when  it  is  used  with  the  end  inside  of 
the  cavity.  Any  other  form  of  bur  with  a  short  head  would  unavoidably 
give  to  the  cavity  margin  either  a  concave  or  a  convex  surface,  both  of 
which  would  be  incorrect. 

The  buccal,  lingual,  and  cervical  enamel  margins  of  a  compound 
approximal  cavity  should  never  be  finished  with  a  round  bur,  even  of 
the  plug-finishing  variety,  but  should  be  smoothed  with  suitable  chisels, 
broad-faced  excavators,  or  approximal  trimmers,  the  latter  being  shown 
in  Fig.  127. 

Fig.  126.  Fig.  127. 


File-cut  enamel  finishing  bur. 


Approximal  trimmer. 


The  practice  of  finishing  enamel  margins  with  sand-paper  disks  is 
very  objectionable,  as  they  are  almost  certain  to  give  to  the  margins  a 


184  PREPARATION  OF  CAVITIES. 

rounded  edge  wliich  cannot  be  filled  and  finisiied  without  leaving  a 
feather  edge  of  the  filling  overlying  the  enamel,  \vhieh  will  eventually 
be  broken  off  or  flared  up,  leaving  an  imperfect  margin. 

The  Gem  cavity  trimmers,  recently  introduced,  are  probably  the  best 
instruments  yet  "devised  for  giving  to  enamel  margins  the  perfection  of 
finish  required  for  gold  filling.  They  produce  a  smooth  but  unpolished 
surface,  to  which  the  gold  is  readily  adapted  and  along  which  it  cannot 
slip  or  slide. 

Classification  of  Cavities.' 
I.     Simple  Cavities  on  Exposed  Surfaces. 
Bicuspids  and  Molars.  Incisors  and  Canines. 

A.  Occlusal.  D.  Labial. 

B.  Buccal.  E.  Lingual. 
C.  Lingual.  F.  Incisal. 

11.     Simple  Approximal  Cavities. 
Incisors  and  Canines.  Bicuspids  and  Molars. 

G.  Mesial  and  distal.  H.  Mesial  and  distal. 

III.  Compound  Cavities. 

Incisors  and  Canines.  Bicuspids  and  Molars. 

I.  Mesio-labial.  P.  Mesio-occlusal. 

J.  Disto-labial.  Q.  Disto-occlusal. 

K.  Mesio-lingual.  R.  Occluso-buccal. 

L.  Disto-lingual.  aS'.  Occluso-lingual. 

31.  Mesio-incisal.  T.  Mesio-disto-occlusal. 
N.  Disto-incisal. 
O.  ]Mesio-disto-incisal. 

In  the  foregoing  classification  the  cavities  have  been  arranged  pro- 
gressively from  the  simplest  (^1)  to  the  most  complicated  (T). 

I.    Simple  Cavities  on  Exposed  Surfaces. 

BICUSPIDS    AND    MOLARS. 

Class  A. — Cavities  upon  the  occlusal  surface  are  very  accessible  and 
in  full  view,  enabling  the  operator  to  see  every  part  of  the  cavity  and 
affording  him  plenty  of  room  in  which  to  operate.  Naturally  those 
nearest  the  front,  as  in  the  bicuspids,  present  the  advantage  of  greater 

^  Following  the  suggestion  of  Dr.  Black,  in  the  above  list  the  word  Untjmd  is  u.sed 
for  the  same  surfaces  in  both  the  upper  and  lower  teeth,  doing  away  with  the  word 
palatal.  In  the  forming  of  compound  terms,  where  the  mesial  or  (li.-<tal  surfaces  are 
included,  these  terms  precede  the  othei-s.  Where  they  are  not  included  and  the  word 
occlusal  is  used,  it  is  given  lirst  place. 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES.  185 

accessibility,  but  none  of  them  are  difficult  to  prepare  and  fill  except 
under  unusual  conditions. 

Usually  the  first  part  of  a  bicuspid  crown  to  become  aifected  by 
caries  is  the  fissure  betsveen  the  cusps.  Sometimes  it  presents  merely  as 
a  black  line  into  which  only  the  point  of  an  explorer  will  penetrate ; 
at  a  later  stage  the  cavity  is  more  fully  defined  by  the  greater  pro- 
gress of  caries  and  the  crumbling  of  the  walls  of  its  orifice.  In  the 
first  instance  the  cavity  is  most  readily  and  comfortably  opened  by 
means  of  the  tapering  fissure  bur  shown  in  Fig.  119.  After  passing  it 
into  one  of  the  terminal  pits  of  the  cavity  it  may  be  drawn  along  toward 
the  other,  opening  the  fissure  quite  freely.  Once  open,  the  decay  may 
be  removed  and  the  cavit}^  shaped  by  a  suitably  sized  round  bur 
(Fig  117).    As  the  decay  has  usually  progressed  farther  in  the  region 

of  the  terminations  of  the  cavity  than  in 
^^'  the  space  between  them,  the  cavity  when 

B  fully  formed  will  be  oblong  in  shape  and 

t  contracted  in  the  centre.     In  Fig.  128, 

A  shows  this    form,  while    B  represents 
„    .^   .      ,        ,    , .       .,  the    same    surface  before   beins:  operated 

Cavity  m  sulcus  of  a  bicuspid.  o      i 

upon. 

In  preparing  the  cavity  no  more  sound  tooth-structure   should  be 

sacrificed  than  is  absolutely  necessary,  but  every  portion  of  decay  should 

be  thoroughly  removed  and  particular  attention  be  given 

to  opening  up  the  minor  fissure  terminations  as  shown  at 

A  A,  B  B  (Fig.  129). 

When  completed,  the  cavity  should  be  very  slightly 
larger  within  than  without,  the  margins  should  present 
no  angles,  but  only  a  series  of  curves  in  outline,  and  the 
marginal  edges  should  be  slightly  bevelled  outwardly. 
Bicuspid  cavities  of  this  character  vary  in  size  according  to  the  extent 
of  decay,  but  the  essential  features  in  each  case  are  very  similar.  The 
lower  first  bicuspid  differs  normally  from  all  others  of  its  kind  in 
having  no  sulcus  and  consequently  no  fissure  between  the  cusps.  In- 
stead of  the  two  cusps  being  separated  by  a  sulcus  they  are  united  by 
a  ridge  of  enamel.  (See  Chap.  I.,  p.  35.)  The  only  points,  therefore, 
that  invite  decay  upon  the  occlusal  surface  of  this  tooth  are  the  two 
pits  that  are  found  one  on  each  side  of  the  ridge.  These  are  to  be 
filled  separately.  They  probably  represent  the  very  simplest  form  of 
simple  cavities  to  be  found  anywhere  in  teeth. 

The  occlusal  surface  of  an  upper  first  or  second  molar  presents  two 
points  liable  to  decay.  One  is  a  pit  formed  by  the  junction  of  two 
small  fissures  near  the  mesial  margin,  and  the  other  is  a  fissure  which 
runs  between  the  disto-buccal,  disto-lingual,  aud  mesio-lingual  cusps- 


186  PREPARATION  OF  CAVITIES. 

Both  are  roprosontod  in  V'\\r^.  \:\().  Wlun  limited  in  extent  tliev  should 
be  opened  in  the  same  manner  as  a  hi(iis|)id  H>siin'  (•avit\-,  l)iit  when 
hirjjer  they  may  be  opened  by  means  of"  a  chisel  ibllowed  by  a  suitable 
bur.  In  these,  as  in  all  cavities  in  sulci,  the  fissures  must  be  followed 
and  opened  up  to  their  extreme.st  limits  in  order  to  ensure  success,  while 
the  maririns  and  maruinal  edges  must  be  so  formed  as  to  be  strong, 
smooth,  and  bevelled. 

The  general   form   of   these    cavities   when    prepared    is    shown    in 
Fig.  131.     It  will  frequently  be  found  that  these  two  occlusal  cavities 

Fir;.  130.  Fig.  131.  Fig.  132.  Fu;.  13.3. 


Upper  molar  fi.ssure  cavities.  I'pper  molar  fissure  cavities  prepared  for  filling. 

are  joined  underneath,  wdiile  near  the  surface  they  are  separated  by  a 
ridge  of  enamel  and  dentin.  In  such  cases  the  ridge  should  be  cut 
away  and  the  tw^o  cavities  converted  into  a  single  larger  one  as  illus- 
trated in  Fig.  132. 

If  the  ridge  were  allowed  to  remain  it  would  almost  certainly  be 
fractured  either  in  the  operation  of  filling  or  subsequently  by  the  force 
of  mastication. 

The  upper  third  molar  differs  from  those  anterior  to  it  in  having 
but  three  cusps  and  consequently  but  one  central  ])it  with  radiating 
fissures.  A  cavity  occurring  here  when  properly  pre])are<l  will  pre- 
sent a  triangular  outline  with  rounded  angles,  as  in  Fig.  133.  The 
terminals  of  fissures  should  always  be  finally  finished  with  a  round  bur 
to  prevent  any  possible  angles  and  opportunity  for  leakage  at  those  points. 

The  lower  first  molar,  as  well  as  the  third,  having  five  cusps  with 
intervening  sulci,  a  cavity  upon  this  surface  will  be  pentagonal  in  out- 
line, as  represented  in  Fig.  134. 

Extreme  care  should  be  exercised  in  preparing  cavities  of  this 
character  to  insure  that  the  fissures  running  between  the  buccal  cusps 
are  fully  opened  and  cleared  of  every  particle  of  decay  and  discolora- 
tion.    Too  often  this  is  overlooked  and  caries  supervenes. 

The  lower  second  molar  with  its  four  cusps  has  two  sulci  inter- 
secting each  other  at  a  right  angle.  Decay  usually  begins  at  the  inter- 
section and  extends  along  the  radiating  arms  of  the  fissures.  If  the 
cavity  were  prepared  l)v  cutting  out  the  fissures  only  it  would  yield  a 
crucial-shaped  cavity  with  four  sharp  or  nearly  sharp  angles  at  the 
intersection,  as  shown  in  Fig.  135.  Owing  to  these  angles  of  dentin  and 
enamel  the  ])erfcct  filling  of  the  cavity  would  be  exceedingly  difficult. 

The  case  may  be  simplified  and  better  results  in  every  way  obtained 


SIMPLE  CAVITIES   ON  EXPOSED  SURFACES. 


187 


by  rounding  these  angles   and  giving  the  cavity  a  form  like  the  one 
shown  in  Fig.  136. 


Fig.  134. 


Fig.  135. 


Fig.  136. 


Lower  first  molar  with  stel- 
late cavity.    Prepared- 


Lower  second  molar  with 
crucial  cavity.  Not  pro- 
perly prepared. 


Cavity  in  lower  second 
molar.  Correctly  pre- 
pared. 


Class  B. — Buccal  cavities  are  seldom  met  with  in  the  bicuspids 
except  at  the  cervix.  In  this  location  they  possess  the  same  features  as 
the  similar  class  of  cavities  occurring  on  the  labial  surfaces  of  the 
incisors.     Their  treatment  will  be  described  under  class  D. 

The  upper  molars  also  are  seldom  found  decayed  on  the  buccal  sur- 
face except  at  the  cervical  border.  Cavities  occurring  at  this  point  are 
usually  narrow  and  long,  following  the  outline  of  the  gum.  They  can 
best  be  prepared  with  an  engine  bur  of  suitable  form,  and  if  occurring 
on  the  second  and  third  molars  a  right-angle  attachment  may  have  to 
be  employed  to  reach  them  conveniently.  Decay  at  this  point  is  often 
of  the  white  variety,  and  as  it  so  nearly  resembles  the  natural  color 
of  the  tooth  extreme  care  will  have  to  be  exercised  to  include  all  of 
the  decalcified  portion  within  the  limits  of  the  cavity.  A  retentive 
form  is  most  conveniently  given  to  these  cavities  by  slightly  undercut- 
ting them  in  the  direction  of  their  length.  In  the  third  molars  it  is 
sometimes  advisable  to  make  an  undercut  or  starting-pit  at  the  distal 
end  for  the  beginning  of  the  filling. 

Sometimes  a  small  cavity  will  be  found  at  about  the  centre  of  the 
buccal  surface  of  the  upper  molars,  but  far  more  frequently  a  cavity 
of  greater  extent  will  be  found  upon  the  same  surface  of  the  lower 
second  molar.  It  originates  in  a  pit  at  the  termination  of  the  fissure 
running  over  from  the  occlusal  to  the  buccal  surface  between  the  two 
buccal  cusps.  Oftentimes  the  cavity  is  so  large  as  to  include  the  greater 
portion  of  this  surface  of  the  tooth.  Its  usual  form  and  appearance  are 
shown  in  Fig.  137. 

Not  infrequently  this  cavity  is  compounded  with  one  on  the  occlusal 
surface.     In  opening  and  preparing  it  a  slightly  undercut 
form  is  readily  given  to  it. 

Class  C. — Decay  rarely  occurs  upon  the  lingual  sur- 
faces of  molars  on  account  of  their  smoothness  and  con- 
vexity and  because  they  are  more  or  less  constantly  rubbed 
by  the  tongue  in  speech  and  mastication.  The  evenness  of 
this  surface  is,  however,  broken  in  the  upper  first  and  sec- 
ond molars  by  a  fissure  extending  over  from  the  occlusal  surface  and 
passhig  between  the  lingual  cusps.     (See  Chap.  I.,  p.  39.)     This  fissure 


Fig.  137. 


Buccal  cavity 
in  lower  sec- 
ond molar. 


188  PREPARATTON  OF  CAVITIES. 

is  (Iccpci"  :iml  more  jiroiiouiK'fd  in  the  first  inohir,  l)iit  in  cacli  tooth 
it  is  generally  the  seat  of  caries  early  or  later  in  life.  In  the  majority 
of  eases  thi.-«  fissure  is  decayed  throMt;h.oiU  its  entire  h-iitith,  forming  a 
compound  cavity,  hut  occasionally  only  the  j>it  at  its  termination  on 
the   lingual   surface   is  affected. 

Another  ])oint  on  the  lingual  surface  liable  to  decav  is  on  or  near  the 
mesio-lingual  angle  of  the  upper  first  molar,  about  midway  between  the 
cervical  and  occlusal  margins.  At  this  place  is  often  found  a  supple- 
mental cusp,  diminutive  in  size,  and  where  it  joins  the  main  surface  of 
the  tooth  a  small  fissure  exists  which  invites  decay.  This  additional 
cusp,  when  it  does  exist,  is  found  only  upon  the  first  molar. 
It  is  shown  at  A  in  Fig.  138.  (See  Chap.  I.,  p.  39.) 
Neither  of  these  cavities  presents  any  difficulties  in  prepara- 
tion except  such  as  occur  from  their  slight  inaccessibility. 

Occasionally,  though  very  rarely,  the  lingual  surface  of  any 
of  the  molars  may  present  a  cavity  of  decay  close  to  the  gin- 
gival line  and  partly  beneath  it.  Such  cavities  are  doubtless  caused  by 
the  retention  of  food  debris  beneath  the  free  margin  of  the  gum,  and 
owing  to  their  position  they  are  difficult  to  treat.  Thev  should  be 
opened  and  packed  over-full  with  cotton  and  sandarac  varnish  or  gutta- 
percha for  a  day  or  two,  to  press  the  gum  away,  after  which  they  may 
be  prepared  and  filled  in  the  usual  manner. 

INCISORS    AND    CANINES. 

Class  D. — Cavities  upon  the  labial  surfaces  of  incisors  and  canines 
are  usually  found  along  the  gingival  margin,  and  are  the  result  of  the 
direct  action  of  acids  probably  formed  at  this  point.  In  the  beginning, 
and  when  small,  they  are  entirely  exposed,  but  when  of  greater  extent 
they  frequently  extend  l)eneath  the  fr(H>  margin  of  the  gum.  They  are 
nearly  always  elliptical  in  outline  and  may  consist  of  simple  decalcified 
enamel  still  retaining  the  usual  surface  form,  or  they  may  possess  the 
common  characteristics  of  cavities  in  general. 

The  opening  and  preparation  of  this  class  of  cavities  arc  not  attended 
with  any  marked  difficulties  except  that  when  they  extend  beneath  the 
gum  care  will  have  to  be  exercised  not  to  wound  this  tissue,  as  the 
consequent  bleeding  would  obstruct  the  view  and  interfere  with  the 
progress  of  the  work.  This  may  be  prevented  by  pressing  and  holding 
the  gum  away  with  a  suitable  instrument  held  in  the  left  hand  while  the 
cavity  is  being  prepared.  Particular  attention  should  be  paid  to  the  care- 
ful preparation  of  the  cervical  margin  of  the  cavity  and  to  its  terminal 
points.  The  former  should  l)c  made  smooth  and  even,  and  the  latter 
should  be  extended  far  enough  to  include  any  enamel  that  shows  the 
least  sign  of  acid  alteration.     Slight  grooves  or  enlargements  at  the 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES.  189 

base  of  the  cavity  along  its  upper  and  lower  margins  will  give  it  a  suf- 
ficiently retentive  form. 

A  second  locality  on  the  labial  surface  where  decay  is  frequently 
found  is  anywhere  between  the  central  portion  and  the  incisal  edge, 
in  pits  and  depressions  that  indicate  imperfect  development  of  the 
enamel.  These  pits  or  grooves  extend  in  a  nearly  straight  line  parallel 
to  the  incisal  edge,  and  are  frequently  the  seat  of  decay. 

When  quite  shallow  they  may  be  obliterated  by  grinding  the  surface 
with  a  small  corundum  wheel  and  polishing,  converting  the 
surface  at  this  point  into  a  distinct  concavity.  When  the 
pits  are  deeper  and  isolated  they  may  be  filled  separately, 
the  result  being  a  lesser  degree  of  conspicuousness  ;  but 
when  they  are  connected  by  a  groove,  as  they  usually  are, 
they  will  have  to  be  converted  into  a  single  cavity  and  pitted  incisor. 
filled.    A  common  type  of  this  defect  is  shown  in  Fig.  139. 

When  these  pits  occur  upon  the  incisal  edge  or  in  close  proximity 
to  it  the  choice  lies  between  an  unsightly  gold  filling,  sections  of  porce- 
lain rods  inserted  into  the  pits,  or  their  removal  by  grinding  and  the 
resultant  shortening  of  the  crown. 

Class  E. — There  is  usually  but  one  point  upon  the  lingual  surface 
of  incisors  and  canines  that  is  liable  to  decay.  It  is  in  the  pit  at  the 
junction  of  the  basilar  ridge  or  cingulum  with  the  adjacent  tooth 
surface.  The  incipiency  of  caries  at  this  point  presents  only  as  a  mi- 
nute cavity,  the  opening  and  shaping  of  which  is  readily  accomplished 
with  a  round  bur.  Although  the  orifices  of  these  cavities  may  be 
small,  the  dark  spot  that  marks  their  direction  is  often  continued  quite 
a  distance  toward  the  pulp  chamber.  This  black  point  should  in  all 
cases  be  followed  to  its  termination  and  obliterated.  As  the  depth  of 
these  cavities  is  greater  than  the  diameter  of  their  orifices,  no  special 
retentive  shape  need  be  given  them. 

The  orifice  should  always  be  bevelled  and  enlarged,  if  necessary,  to 
include  any  neighboring  fissures. 

When  these  cavities  are  of  greater  extent  they  are  prepared  and 
filled  like  others  of  similar  size  and  form. 

Class  F. — Cavities  upon  and  confined  to  the  incisal  edge  of  incisors 
and  canines  are  easily  pre})ared  on  account  of  their  accessibility.  This 
particular  surface  should,  and  generally  does,  remain  free  from  decay 
on  account  of  the  attrition  to  which  it  is  constantly  subjected  ;  but 
when  defects  in  the  enamel  exist,  caries  sometimes  occurs  in  connection 
with  it. 

This  surface  often  needs  covering  with  gold  to  check  abrasion  in 
cases  where,  after  middle  life,  the  crowns  (especially  those  of  the  upper 
teeth)  have  been  shortened  by  excessive  wear.     Under  these  conditions 


190  PREPARATION  OF  CAVITIES. 

the  surface  iiuist  he  so  prepared  and  sliaped  as  to  retain  the  lipoid  that 
is  to  eover  and   protect  it  just  as  thoui^h  caries  had  originally  injured 
the  part.     lu  ibnning  the  cavity  in   tlie  exposed   dentin 
Fig.  140.       j^  j^  oidy  necessary  to  cut  dee])ly  enough  to  aHord  a  lodg- 
ment for  the  filling,  hut  the  orifice  must  he  so  enlarged  and 
excessively  hevelled  as  to  reach  to  the  marginal  edge  of 
enamel  all  around.      This  is  done  to  protect  the  enamel 
from  chipping  or  fracture  in   mastication.     To  aflord  the 
greatest  .security  U)  the  filling  the  cavity  should  be  under- 
cut throughout  its  whole  extent.      AVhen  thus  prepared, 
c^avitv  or"in-     the  cavity  in  cross-section  will  resemble  a  double  dove-tail 

cieal  surface.       aS  shown  iu  Fig.   140. 

II.    Siraple  Appro ximal  Cavities. 

INCISORS    AND    CANINES. 

Class  G. — Cavities  upon  the  mesial  and  (Ji.sfal  surfaces  of  the 
anterior  teeth  present  only  the  difficulty  arising  from  inaccessibility. 
To  reach  and  operate  upon  these  cavities,  the  teeth,  if  in  normal  contact, 
will  usually  have  to  be  pressed  apart  either  by  gradual  wedging  or  by 
immediate  separation  with  a  "separator."  Even  after  this  has  been 
accomplished  the  cavity  cannot  be  operated  upon  in  a  direct  way  as  are 
cavities  upon  exposed  surfaces,  but  will  have  to  be  approached  from 
either  the  labial  or  lingual  aspect  of  the  crown.  To  do  this,  if  the 
cavity  be  small,  will  generally  necessitate  an  additional  enlargement  of 
the  cavity  toward  the  surface  from  which  it  is  to  be  approached.  As 
the  lesser  of  two  evils  the  enlargement  is  usually  made  toward  the 
lingual  surface,  for  in  this  way  there  will  be  no  exposure  of  gold  when 
the  filling  is  completed.  When  the  cavity  is  of  larger  size  and  the 
enamel  wall  on  the  labial  surface  has  been  weakened  by  caries  it  will 
have  to  be  removed,  and  access  will  thus  necessarily  be  afforded  from 
that  side.  Whenever  possible,  however,  undue  enlargement  of  the 
cavity  and  consequent  exposure  of  gold  should  be  avoided. 

In  ordinary  cavities  upon  the  approximal  surface  the  frail  walls 
bordering  the  orifice  should  be  broken  away  with  a  small  chisel,  and 
after  the  decay  has  been  removed  by  means  of  burs  or  excavators  and 
the  proper  form  given  to  the  cavity,  the  margins  should  be  carefully 
smoothed  and  bevelled  from  within  outward  with  small  plug-fini.shing 
burs  or  with  the  side-cutting  edge  of  the  small  chisel  shown  in  Fig.  122 
and  here  reproduced  (Fig.  141). 

Anchorage  is  obtained  in  these  cavities  by  flattening  the  cervical  wall 
so  as  to  form  distinctly  rounded  angles  with  the  labial  and  lingual  walls 
respectively.      Slight  depressions   should    also  be   made   at   the  labio- 


SIMPLE  APPBOXIMAL  VAVITIES.  191 

cervico-axial  and  the  linguo-cervico-axial  angles  for  starting  and  securing 
the  first  portions  of  the  filling.     A  shallow  undercut  in  the  dentin  near 
the  incisal  border  will  also  be  necessary  to  serve  as 
an  opposite   anchorage.      Retaining   grooves    should 
never  be  made  in  the  labial  or  lingual  walls  of  the  y|! 

cavities,  as  they  would  seriously  weaken  them.  In 
approximal  cavities  of  large  size,  where  they  extend 
from  near  the  incisal  edge  to  or  beyond  the  free  mar- 
gins of  the  gum,  the  difficulties  of  producing  a  perfectly 
formed  cavity  are  greatly  increased.  While  affording 
greater  ease  of  approach  on  account  of  their  size,  the 
cervical  border  of  this  class  of  cavities  is  apt  to  be  less 
perfectly  prepared  owing  to  its  obscure  location.  When 
the  cervical  border  extends  beneath  the  free  margin  of  Delicate  three-sided 
Mie  gum  the  latter  should  be  pressed  and  held  away        chisel,   useful    for 

,.  .  ,  •in  1  opening  cavities  on 

durmg  excavating,  so  that  the  cervical  wail  may  be        approximal       sur- 
plainly  seen  and  operated  upon  throughout  its  extent.        ^^^'^^• 

Cutting  of  the  wall  should  be  sufficiently  extended  rootward  as  well 
labially  and  lingually  to  include  any  defects  or  checks  in  the  enamel 
bordering  it,  and  should  be  made  entirely  smooth  and  free  from  angles,  for 
it  is  the  most  vulnerable  border  of  the  cavity  after  the  filling  has  been 
completed.  Should  the  cavity  extend  near  to  the  enamel  termination  at 
the  cervix,  it  will  be  best  to  still  further  extend  it  so  as  to  pass  beyond 
this  margin  ;  for  if  a  small  portion  of  enamel  be  left  t^ere  it  will  be  liable 
to  be  broken  away  in  the  process  of  filling  and  thus  render  difficult  the 
proper  finishing  of  this  portion  of  the  approxiuial  surface. 

So,  also,  if  the  cavity  on  account  of  its  size  should  approach  very 
near  to  the  incisal  edge,  it  is  best  to  remove  this  frail  corner  and  con- 
vert the  cavity  into  a  compound  one.  Where  such  a  weak  corner  is 
allowed  to  remain  it  is  very  frequently  broken  away  in  subsequent  mas- 
tication. Such  a  result  is  shown  in  Fig.  142.  An  accident  like  this  is 
more  likely  to  occur  in  thin,  fiat  teeth  where  the  plates  of  enamel  meet- 
ing at  the  incisal  edge  have  little  or  no  dentin  between  them. 

Where  doubt  exists  as  to  whether  the  corner  should  be  p,  ^^^ 
removed  or  allowed  to  remain,  it  is  well,  after  the  cavity  has 
been  prepared,  to  test  the  strength  of  the  corner  by  strong  pres- 
sure upon  it  in  the  direction  of  the  long  axis  of  the  tooth  with 
a  piece  of  orange-wood.  If  it  resists  this  strain  it  will  prob- 
ably resist  the  force  of  mastication,  and  if  it  break  away  under 
the  test  it  will  demonstrate  that  it  would  have  been  unwise  to  allow  it 
to  remain. 

If  the  corner  be  left  as  a  border  and  support  for  the  filling  it  should 
not  be  weakened  by  a  deep  retaining  groove.    Such  groove  or  anchorage 


192  PREPARATION  OF  CAVITIES. 

should  1)0  sluillow,  and  as  far  removed  IVoiii  the  ineisal  border  as  tlie 
conditions  will  j)erniit. 

In  nianv  oases  whore  the  incisal  wall  would  he  seriously  weakened 
by  any  attempt  to  use  it  as  an  anohora<;o  or  su))port  for  the 
filling,  and  where  it  seems  undesirable  to  roiuovo  it.  an  ox- 
oellont  anohoraco  for  the  lower  border  of  the  filliui:;  may  be 
obtained  by  outtinjj^  an  extension  upon  the  lingual  surfaoe  in 
the  form  of  an  arm,  as  shown  in  Fig.  14.'3.'  Such  extension, 
if  made  but  little  deeper  than  the  enamel,  will  not  materially 
weaken  the  tooth  and  will  seeuro  the  filling  perfectly. 

Its  position  should  bo  near  the  incisal  edge,  but  not  so 
close  to  it  as  to  weaken  the  part. 
In  the  anterior  teeth  the  relative  difficulties  betw^een  mesial  and  distal 
cavities  are  insignificant. 

BICUSPIDS    AND    MOLARS, 

Class  H. — The  preparation  of  small  cavities  on  the  mesial  and 
distal  surfaces  of  the  bicuspids  and  molars,  though  simple  in  character, 
is  usually  most  difficult  of  thorough  performance.  This  is  duo  entirely 
to  their  inaccessibility  when  the  teeth  are  closely  approximated.  How 
to  approach  these  cavities  is  often  a  matter  of  no  small  concern  to  the 
student  or  young  practitioner,  and  the  preparation  and  filling  of  them 
is  generally  more  difficult  than  that  of  larger  and  more  complicated 
cavities  in  exposed  situations.  To  lessen  the  difficulty  of  approach  it  is 
important,  whenever  practicable,  to  create  by  wedging  beforehand  as 
great  a  separation  as  possible  between  the  teeth.  The  greater  the  space 
gained  the  less  the  difficulty  of  approach. 

When  conditions  warrant  cutting  down  to  them  from  the  occlusal 
surface,  and  thus  converting  them  into  compound  cavities,  it  is  the  better 
plan  to  pursue,  for,  although  this  method  involves  the  loss  of  more  tooth 
tissue,  it  greatly  facilitates  the  operation  of  filling  by  affording  additional 
space  and  accessibility, 

AVhen,  however,  the  cavities  are  small  and  situated  at  the  centre  or 
toward  the  gingival  margin  of  the  approximal  surface,  they  should  be 
dealt  with  as  are  similar  cavities  in  the  anterior  teeth,  depending  upon 
previous  spacing  for  room  in  w'hich  to  work. 

These  cavities  can  usually  be  best  opened  and  maiidy  prepared  with 
a  round  bur.  After  the  caries  has  been  removed  and  the  walls  defined 
and  prepared,  the  cavity  may  be  made  retentive  in  form  by  slight  under- 
cutting throughout  its  entire  circumference,  or  it  may  be  enlarged  at  two 
opposite  points  only.     The  cervical  wall  can  be  shaped  with  an  obtuse- 

'  Dental  Cosmos,  vol.  xxxvi.,  p.  198^  and  Dental  Review,  vol.  ix.,  pp.  812  and  819. 


COMPOUND  CAVITIES. 


193 


angle  hatchet  excavator  as  illustrated  in  Fig.  144,  and  the  lower  or 
occlusal  wall  be  slightly  undercut  by  an  acute-angle  excavator  like 
Fig.  145. 


Fig.  144. 


Fig.  145. 


Obtuse-ansrle  hatchets. 


Acute-angle  hatchets. 


The  sharp  angles  on  the  cutting  edges  of  these  excavators  should 
be  rounded  before  being  used,  so  as  to  avoid  the  formation  of  angles  in 
the  cavity. 

As  the  enamel  rods  on  this  surface  radiate  outwardly  at  such  an 
angle  as  to  give  the  proper  bevel  to  the  orifice  of  the  cavity,  a  careful 
following  of  their  lines  in  the  preparation  of  the  cavity  margins  will 
be  all  that  is  necessary  to  give  them  the  desired  form  and  strength. 

Where  simple  cavities  upon  the  approximal  surface  are  large  they 
may  extend  so  near  to  the  occlusal  surface  as  to  weaken  it.  When  this 
is  the  case  the  enamel  wall  should  be  cut  away  and  the  cavity  converted 
into  a  compound  one  of  the  approximo-occlusal  type. 


III.    Compound  Cavities. 


INCISORS   AND    CANINES. 


Fig.  146. 


Classes  I  and  /. — Mesio-labial  and  disto-lahial  cavities  occur  from 
the  near  approach  or  union  of  simple  cavities  upon  their 
respective  surfaces.  Cavities  of  considerable  length  up- 
on the  approximal  and  labial  surfaces  are  very  apt  to 
join  one  another  by  extension  of  caries.  When  they 
do  not  join  they  are  usually  separated  by  a  narrow  terri- 
tory of  more  or  less  impaired  tooth  tissue,  and  in  such 
cases  must  be  united  to  obtain  a  satisfactory  result.  Each 
cavity  should  be  as  nearly  prepared  as  possible  separately,  after  which 
the  intervening  tissue  should  be  cut  away  and  the  margins  of  the  channel 
connecting  the  two  be  made  as  strong  and  smooth  as  possible.  This 
channel  will  usually  be  of  less  width  than  either  of  the  cavities,  but  not 
more  difficult  to  fill  on  this  account 
such  a  compound  cavity. 

13 


Mesio-labial    cav- 
ity prepared. 


Fig.  146  shows  a  front  view  of 


194  PREPARATION  OF  CAVITIES. 

Whether  tlie  cavitv  1h'  a  iiiosi(»-lal>i:il  or  a  (Jistu-lahial  one  will  not 
materially  atleot   the   inaiincr  or  difficulty  of  o|)t'ratino;. 

Classes   7v'  and   L. — Mcs-io-fiiif/iui/  and    (lisfo-Ziuf/nal   cavities   are 

formed   in  the  same  manner  as  those  of  classes  /  and  ./,  except  that  in 

^      ,,_     these  cases  tlie  linuual  surface  is  involved  instead  of  the  labial. 
Fio.  14/.       ^  -^ 

Kxtensive  caries   in   the  region  of  the  basilar   pit   or  of  the 

iissures  connected   with    it   often   approaches  so  nearly   to  an 

aj)))roxinial  cavitv  in   the  same  tootli  as  to  demand   the  union 

of  the   two   (see    Fiy.   147).     The  method  of  ])reparinir  and 

unitins:  the  two  is  substantially  the  same  as  that  followed  in 

classes  /  and  J,  just  described, 

A  mesio-lintjual  cavity  is  perhaps  more  easily  prepared  and  filled 

than  a  mesio-labial  one,  for  in  its  preparation  the   free  cutting  away 

of  the  intervening  wall  is  permissible,  which  affords  increased  room  for 

operating. 

Fortunately,  a  lingual  cavity  rarely  extends  so  far  as  to  connect  with 
both  a  mesial  and  a  distal  cavity.  When  it  does,  the  joining  of  the 
three  cavities  very  seriously  weakens  the  crown  at  the  point  where  the 
greatest  strain  occurs. 

Classes  M  and  N. — These  classes  include  cavities  upon  either  the 
mesial  or  distal  surfaces  connecting  with  a  cavity  upon  the  incisal  edge. 
They  usually  occur  in  consequence  of  the  wearing  away  of  the  latter 
surface  throu<rh  attrition  or  from  the  necessitated  removal  ol"  the  incisal 
corner  on  account  of  weakness.  Both  the  ai)pi'oxinial  and  incisal  cavi- 
ties may  be  ])rc})ared  separately  as  described  in  classes  i*' and  (r,  after 
which  they  should  be  connected,  the  walls  made  strong  and  smooth  and 
properly  bevelled. 

A  typical  cavity  of  this  class  is  shown  in  Fig.   148.     In  all  such 

cases  the  labial  plate  of  enamel  should  be  preserved  intact  as 

far  as  possible  for  ai)pearance  sake,  and  if  any  cutting  has  to 

be  done  to  increase  the  size  or  depth  of  the  incisal  portion  of 

lA  ^    1      *^^^  cavity,  it  should  be  done  at  the  expense  of  the  lingual  wall. 

(ISHIi      J^''  order  to  })rotect  the  labial  wall  from  possible  fracture  in 

Apiiroximo-    niasticatiou  the  enamel  should  be  bevelled  outwardly  (as  men- 

inrisaicav-    tioucd  uudcr  cUiss  F)  SO  tluit  wlicu   filled  the  gold  alone  will 

come  in  contact  with  the  op})osing  teeth  in  mastication. 

The  only  anchorage   needed   for  this  class  of  cavities   is  a  slight 

undercut  along  the  cervical  wall  and  a  dovetailed  form  of  the  incisal 

portion  of  the  cavity. 

In  many  cases  there  is  no  cavity  upon  the  incisal  edge,  but  where 
opportunity  offers  for  making  one  (as  in  the  case  of  thick  or  worn  teeth) 
this  method  of  forming  a  compound  cavity  affords  the  greatest  possible 
support  and  security  for  a  large  approximal  filling  involving  the  ap- 
proximo-incisal  angle. 


COMPOUND   CAVITIES.  195 

Where  the  crown  is  thin  and  unworn  upon  the  incisal  surface  a  com- 
pound cavity  of  this  character  cannot  be  formed,  but  the  same  result  as 
to  anchorage  may  be  obtained  by  cutting  an  extension  upon  the  lingual 
surface  of  suitable  size,  form,  and  depth,  as  described  on 
p.  192.  One  form  of  such  extension  where  the  corner  is 
gone  is  shown  in  Fig.  143.^  Another  form,  represented 
in  Fig.  149,-  consists  of  giving  the  extension  a  curved  or 
hooked  form.  Both  forms  serve  the  same  purpose,  for 
they  afford  in  these  cases  perfectly  secure  anchorage  which  Auxiliary  dove- 
could  not  be  obtained  so  well  in  any  other  way.  *^^^  anchorage. 

Class  0. — Ifesio-disto-indsal  Cavities. — Cavities  of  this  character 
differ  from  the  preceding  ones  principally  in  extent.  The  method  of 
preparation  in  each  case  is  similar  and  the  operation  requires  the 
exercise  of  great  skill  and  care  in  order  to  produce  the  best  results. 
In  both  cases  the  following  points  will  have  to  be  observed  : 

As  the  operations  are  extensive  in  character,  good  strong  walls  are 
needed  on  all  sides  to  withstand  the  force  exerted  in  the  introduction  of 
the  filling. 

All  maro;ins  must  be  smooth  and  nicelv  bevelled. 

No  angles  or  checked  enamel  must  exist  along  the  borders. 

All  enamel  should  be  supported  by  underlying  dentin,  although 
to  avoid  the  exposure  of  gold  the  labial  plate  (which  is  thicker  than 
the  lingual)  may  sometimes  be  left  thus  unsupported  for  a  short  distance 
along  the  approximal  and  incisal  margins. 

No  deep  anchorages  will  be  required.  Only  slight  ones  are  needed 
to  start  the  filling  at  the  cervical  wall,  for  the  form  of  the  filling,  when 
completed,  will  be  such  as  to  afford  the  greatest  possible  security. 

BICUSPIDS    AND    MOLARS. 

Class  P. — Mesio-ocdusal  cavities  in  bicuspids  and  molars  represent 
a  class  not  only  frequently  met  with  and  difficult  to  fill,  but  one  also  in 
which  a  large  proportion  of  fillings  fail.  This  is  largely  due  to  the 
improper  shaping  of  the  cavity  and  the  imperfect  placing  and  adaptation 
of  the  filling.  When  these  cavities  are  of  moderate  size,  not  extending 
as  far  as  the  gingival  margin  on  the  mesial  surface  and  without  any 
great  width  in  a  buccal  or  lingual  direction,  the  preparation  and  filling 
of  them  is  not  attended  with  any  great  difficulty ;  but  where  they 
extend  beneath  the  gum  margin  and  are  much  spread  out  laterally  they 
present  complications  that  are  difficult  to  overcome. 

The  cervical  margin  of  such  cavities  as  extend  only  to  or  near  to 
the  free  margin   of  the  gum  has  been  aptly  styled   the  "  vulnerable 

^  Dental  Review,  vol.  ix.  pp.  812  and  819. 

*  I.  C.  St.  John,  D.  D.  S.,  Dental  Cosmos,  vol.  xxxvi.  p.  198. 


196  PREPARATION  OF  CAVITIES. 

point,"  because  when  tailure  occurs  in  tlicsc  lillinixs  it  u>n:illy  boj^ins  at 
this  margin.  When,  however,  the  cavity  wall  extends  licncath  the  gum 
margin,  althouoh  the  difficulties  of  operatintr  are  inereax'd,  recurrence 
of  decay  is  seldom  met  with,  because  the  conditions  favorable  to  decay 
are  not  present  there. 

In  the  ]ire])aration  of  these  cavities  the  teeth  should  have  been  pre- 
viously separated  in  order  to  afford  light  and  room  for  excavating,  as  well 
as  for  the  subsequent  introduction  and  finishing  of  the  filling.  If  the 
cavity  extend  beneath  the  margin  of  the  gum  the  latter  should  be 
pressed  away  by  packing  the  cavity  over-full  with  gutta-percha  for  a 
day  or  two  previously. 

After  opening  and  roughly  preparing  the  cavity  the  rubber  dam 
should  be  adjusted  and  the  cavity  thoroughly  dried,  after  which  the  prep- 
aration can  be  completed  more  satisfactorily,  as  the  dryness  of  the  tooth 
will  enable  the  oj)erator  to  readily  distinguish  between  sound  and  un- 
sound tissue. 

Whether  the  cavity  be  of  large  or  moderate  size,  simple  or  difficult 
in  character,  the  niceties  of  preparation  must  receive  due  consideration. 
The  cervical  portion  of  the  cavity  should  be  cut  away  until  a  strong 
sound  wall  is  obtained  having  no  distinct  angles,  no  decalcified  tooth 
structure  bordering  it,  and  no  checks  in  the  enamel.  Should  either 
of  the  latter  be  found,  further  cutting  of  the  wall  will  be  necessary 
until  these  defects  are  entirely  obliterated. 

If  the  cavity  should  extend  rootward  to  near  the  termination  of  the 
enamel,  it  will  be  necessary  to  deejien  the  cavity  so  as  to  include  this 
portion,  otherwise  injury  will  be  liable  to  result  from  the  fracture  of  this 
frail  section  of  enamel  during  filling. 

The  outline  of  the  cervical  wall  should  be  distinctly  flattened,  as  shown 

„      ,..        „      ,.,  in  FiiT.  ISO,  A,  on  accountof  the  assistance  it  renders 

Fig.  150.        Fig.  lol.  .  . 

in  filling.     The  buccal  and  lingual  walls  must  be 

dressed  to   a  smooth  outline  and  bevelled,  and 

,   .,, ,       ^  ^—   „      should  be  extended  so  far  toward  the  buccal  and 

^  ^  •=  lingual   surfaces  as  to  free  them  from  the  danger 

of  future  decay.     In  Fig.  151  the  dark  portion 

represents  the  buccal  aspect  of  the  completed  filling  somewhat  exaggerated. 

None  of  these  walls  should  be  deeply  undercut  to  assist   in  either  the 

introduction  or  retention  of  the  filling,  for  such  undercutting  is  a  source 

of  weakness,  but  shallow  grooves  are  not  objectionable  when  needed. 

Starting  pits  or  grooves  should  not  be  made  in  the  cervical  wall  except 

in  rare  cases,  slight  depressions  at  the  axio-gingivft-buccal  and  the  axio- 

gingivo-lingual  angles  being  sufficient  to   furnish  all  the  retentive  form 

needed  in  this  portion  of  the  cavity. 

That  portion  of  the  cavity  in  the  sulcus  on  the  occlusal  surface  should 

be  made  flat  and  also  retentive  by  widening  it  at  its  termination,  as  shown 


COMPOUND  CAVITIES. 


197 


at  A,  Fig.  152.  Where  the  occlusal  and  approximal  portions  of  the 
cavity  meet,  the  angles  should  be  removed  and  the  cavity  well 
opened  so  as  to  afford  access  and  give  strength  to  the  filling  (b,  Fig.  152). 

Fig.  152.  Fig.  153.  Fig.  154. 


Prepared  cavity  and  anchorages. 


Prepared  cavity  and  anchorages. 


Fig.  153  represents  a  compound  cavity  of  this  class  incorrectly  formed. 
In  it  moderately  sharp  angles  are  seen  at  the  points  where  the  occlusal 
and  approximal  portions  of  the  cavity  join. 

In  Fig.  154  the  black  portion  represents  the  floor  of  the  cavity ;  a 
and  B  indicate  the  points  to  which  the  buccal  and  lingual  walls  should 
be  cut ;  c  and  d  show  the  curved  form  of  cavity  after  the  occluso-approxi- 
mal  angles  have  been  removed,  while  the  curved  line  outside  of  the 
cavity  indicates  the  approximal  contour  of  filling,  with  contact  point  at  H. 

Fig.  155  represents  a  compound  cavity  (mesio-occlusal)  in  a  lower 
second  molar.  These  cavities  differ  from  similar  ones  in 
bicuspids  principally  in  having  the  occlusal  portion  of 
the  cavity  extend  in  different  directions  along  the  sulci. 
All  of  the  terminations  should  be  well  rounded  and  in 
no  portion  of  the  cavity  should  distinct  angles  be  allowed  Mesio-occiusai  cav- 

,  .  ity  in  lower  sec- 

to  remain. 


Fig.  155. 


ond  molar, 
pared. 


Pre- 


FiG.  156. 


Class  Q. — Disto-ocdusal  cavities  in  either  the  bicus- 
pids or  molars  are  not  essentially  different  from  mesio-occlusal  cavities 
in  the  same  teeth.  Owing  to  their  position  they  are  more  difficult 
of  approach,  but  their  manner  of  preparation  and  their  form  are  vir- 
tually the  same. 

Class  R. —  Occluso-buccal  cavities  are  more  frequently  met  with 
in  the  lower  than  in  the  upper  molars.  This  is  due  to  the  general 
presence  of  a  pit  upon  the  buccal  surface  of  the  lower  molars,  in  which 
decay  by  extension  reaches  so  near  to  the  occlusal  surface 
that  the  occluso-buccal  wall  is  weakened  and  has  to  be 
removed.  Coincident  with  this  there  is  usually  a  cavity 
of  some  size  upon  the  occlusal  surface,  and  the  union  of 
the  two  cavities  becomes  necessary  to  insure  a  satisfactory 
result  in  filling  them.  A  common  type  of  such  cavity 
is  shown  in  Fig.  156. 

The  channel  connecting  the  two  cavities  is  usually 
narrower  than  either  of  the  latter  and  also  more  shallow, 
thus  conserving  the  strength  of  the  tooth.      As,  however,  the  strain 
upon  the  walls  bordering  this  channel  is  very  great  in  mastication  they 


Occluso-buccal  cav- 
ity in  lower  molar. 
Prepared. 


198 


PRKPARATIOS   OF  CAVITIES. 


Fig.  157. 


should  he  triiniiicd    until  solidity  is   olitaincfl,  :iud    mIso   he  considerably 
bevelled  f<>i-  purposes  of"  stfeuiitli. 

Cr.Ass  N. —  ()rc/iis<>-/lit(/ii(i/  cavities  in  the  l)icusj)ids  and  molars  are 
of  rare  occurrence  except  in  the  upper  first  and  second  molars,  where 
they  follow  the  line  of  the  sulcus  extending  between  the  mesio-lingual 
and  disto-lingual  lobes.  Sometimes  the  cavity  is  nearly  confined  to  the 
occlusal  surtiice,  running  over  on  to  the  lingual  surface  but  slightly. 
In  such  cases  the  cavity  is  easily  prepared  by  simply  cutting  the  occlusal 
cavity  through  to  the  lingual  surface,  thus  giving  it  a  relatively  uniform 
depth  at  all  points. 

At  other  times  the  fissure  on  the  lingual  surface  will  extend  farther 
toward  the  cervical  margin,  and  the  cavity  when  prepared 
will  have  the  form  of  an  L,  the  longer  arm,  A,  represent- 
ing the  occlusal,  and  the  shorter  one,   B,  the  lingual  por- 
tion of  the  cavity  (see  Fig.   157).      Where  the  extent  of 
decay  does  not  demand  it,  it  would  be  a  mistake  to  make 
the  floor  level  of  the  two  portions  of  the  cavity  uniform, 
as  the  extensive  removal  of  sound  dentin  would  greatly 
weaken  the  disto-occluso-lingual  cusp. 
Where  extensive  decay  has  already  weakened  this  cusp  it  is  better  to 
amputate  it  below  the  level  of  the  occlusal  plane  and  extend  the  filling 
over  it. 

Class  T. — With  the  exception  of  those  iniusual  cavities  which 
involve  the  greater  portion  of  the  crown  of  a  tooth,  the  mcsio-disto- 
ocdusal  cavities  in  bicuspids  and  molars  are  the  largest  in  extent  of  any 
met  with.  Being  well  exposed  there  is  no  lack  of 
either  light  or  room  in  which  to  operate,  and  the  only 
difficulty  associated  with  their  preparation  and  filling 
lies  in  their  size  and  extent. 

Their  prej)aration  is  accomj)lished  in  the  same  man- 
ner as  those  of  classes  P  and  Q,  except  that  no  special 
retentive  form  need  be  given  to  the  occlusal  portion, 
for  with  the  filling  once  in  place  its  general  form  will 
eecnrc  it  in  position.     Fig.  158  represents  a  typical  cavity  of  this  class 
in  a  bicuspid  tooth. 


Fig.  158. 


CHAPTER    VIII. 

EXCLUSION  OF  MOISTURE— EJECTION  OF  THE  SALIVA- 
APPLICATION  OF  THE  DAM  IN  SIMPLE  CASES,  AND 
IN  SPECIAL  CASES  PRESENTING  DIFFICULT  COMPLI- 
CATIONS—NAPKINS AND  OTHER  METHODS  FOR  SECUR- 
ING DRYNESS. 

By  Louis  Jack,  D.  D.  S. 


The  interference  of  the  secretions  of  the  mouth  offers  a  considerable 
obstacle  to  the   treatment  of  the  teeth.     In  some  in-  Fig.  160. 

stances  the  flow  is  naturally  excessive,  and  in  all  cases 
it  is  stimulated  by  the  operative  procedures. 

An  excessive  flow  of  saliva  is  uncomfortable  to  the 
patient ;  its  accumulation  also  impedes  the  operation, 
and  interferes  with  the  view  of  parts  by  refracting 
the  rays  of  light. 

During  the  preparation  of  accessible  cavities,  par- 
ticularly those  of  the  upper  front  teeth  and  the  occlusal 
surfaces,  the  accumulation  may  be  carried  off  by  the  use 
of  a  SALIVA  EJECTOR,  a  simple  form  of  which  is  shown 
in  Fig.  159,  which  form,  or  some  modification  of  it,  is 
used  where  a  connection  can  be 
made  with  the  water  supply,  and 
ordinarily  it  is  used  in  association 
with  the  fountain  cuspidors.  An- 
other form,  which  is  connected 
with  a  small  reservoir  of  water, 
is  shown  in  Fig.  160.  Either 
of  these  forms  has  a  further  use 
for  drawing  off  the  saliva  in  con- 
nection with  the  employment  of 
the  rubber  dam  to  lessen  the  dis- 
comfort of  the  patient. 


Fig.  159. 


Use  op  Rubber  Dam. 

During  the  preparation  of  cavi- 
ties on  the  approximal  surfaces  of 
the  bicuspids   and  molars  where    it    is  essential    to   have  unrestricted 

199 


200  EXCLUSIOX  OF  MOISTURE. 

vicir  ami  the  r.rchislon  of  blood,  the  jircsence  of  which  is  insej)arah]e 
from  thorougli  pivparatiuii  of  the  ciTvioal  margins,  it  is  necessary  to 
make  use  of  the  KUBiJi:n  dam.  Wlien  used  for  this  j)urpose  the 
material  generally  becomes  imj)airecl  hy  the  action  of  the  instruments 
in  their  free  use  at  the  cervix  ;  but  the  economy  of  time  and  the  essen- 
tials of  thorough  performance  of  this  class  of  operations  warrant  the 
application  in  many  cases  during  this  portion  of  the  treatment. 

^^'hen  the  case  is  ready  for  the  filling  process  a  new  piece  of  the  dam 
should  be  prepared,  and  adjusted  with  great  care  to  prevent  the  ingress 
of  the  least  moisture.  "Without  this  appliance  the  greatest  skill  is  pow- 
erless to  secure  soinid  results  in  large,  difficult,  or  complicated  cases. 
The  introduction  of  this  invention  has  made  it  possible  to  execute 
with  gold,  operations  which  previously  were  impossible  ;  not  the  least 
advantage  resulting  from  its  use  is  that  the  operator  has  free  use  of  the 
left  hand  to  assist  the  right. 

Quality  of  the  Rubber. — The  quality  of  the  rubber  greatly  modi- 
fies the  facility  of  its  application.  It  should  be  of  medium  thickness 
and  of  light  color,  as  it  then  absorbs  less  light.  It  should  be  freely 
extensible  and  so  elastic  that  when  the  thumb  is  forcibly  pressed  into  it 
it  returns  to  its  normal  form  on  the  removal  of  the  force.  If  it  re- 
sponds to  this   test  it  will  not  tear  if  fairly  applied. 

The  size  and  form  of  the  piece  should  be  such  as  to  avoid  encum- 
bering the  face  of  the  patient  and  to  permit  the  lateral  extension  to  be 
folded  out  of  the  way  in  such  manner  as  to  prevent  obstruction  of  the 
view.  The  f«u'm  generally  best  suited  is  a  triangle,  Mhich  form  also 
permits  of  its  most  economical  use. 

For  the  front  teeth  the  piece  should  be  moderately  small  ;  for  the 
bicuspids  and  molars  the  size  should  be  ample  and  is  best  adapted  when 
cut  from  strips  about  seven  and  a  half  inches  in  width. 

The  selected  piece  should  have  holes  cut  in  it  of  such  size  as  to 
correspond  with  the  dimensions  of  the  teeth  over  which  it  is  to  pass. 
AVhen  more  than  one  hole  is  required  the  holes  should  be  at  such  dis- 
tances apart  as  Mill  present  a  sufficient  amount  of  material  to  allow  for 
the  take-up  in  the  application,  so  that  the  strait  which  passes  between 
the  teeth  shall  be  sufficient  to  allow  the  edge  to  be  carried  upward  to 
form  a  valve  at  the  cervices  of  both  teeth  and  not  be  under  such  strain 
as  to  interfere  with  the  valvular  action  of  the  edges  of  the  rubber.  At 
the  same  time  there  should  be  no  excess  to  hamper  the  view  or  inter- 
fere with  the  placement  of  the  filling  material. 

Attention  to  the  valvular  arrangement  of  the  dam  at  the  cervix  will 
avoid  subsequent  difficulty  and  will  prevent  in  many  instances  the 
infliction  of  pain  in  using  ligatures  except  upon  the  tooth  under  treat- 
ment and  the  adjacent  one.  The  diagrammatic  appearance  of  this 
valve  is  sh!>wu   by  Fig.  161,  and  in  perspective  by  Fig.  162,  a,b,v,d. 


USE  OF  RUBBER  DAM. 


201 


Fig.  161. 


Fig.  163. 


Fig.  162. 


h  c  d 

Diagrammatic  drawing  :  form  of  valve. 


The  holes  in  the  rubber  may 
be  formed  with  a  punch  of  suit- 
able size,  which  should  be  forced 
upon  the  end  of  a  close-grained 
piece  of  hard  wood.  They  may 
be  made  with  a  little  practice 
by  drawing  the  rubber  over  a 
round-ended  instrument  with 
some  force  and  pricking  the 
rubber  at  a  suitable  point  with 
a  sharp  knife,  Avhen  a  round 
section  escapes.  The  difference 
in  size  of  the  holes  is  deter- 
mined by  the  distance  from  the 
end  of  the  instrument  at  which 
the  puncture  is  made.  The  deter- 
mination, however,  of  size  and 
distance  is  not  easily  made  in 

this  manner.  The  best  appliance  for  the  purpose  is  the  Ainsworth 
punch  (see  Fig.  163),  with  which  complete  control  of  size  and  distance 
may  be  easily  effected. 


The  Ainsworth  punch. 


202 


EXCLUSION  OF  MiHSTVRE. 


The  arrangement  of  the  holes  in  the  tii:m^iil:ir  piece  should  dilVcr 
for  each  section  <»f"  the  inoiitli. 

Fig.  1()4  shows  a  piece  for  tluMv/fZ/vr/  ineisnts.  The  figures  represent 
inches. 

Fig.  1G5  shows  the  arrangement  of  holes  for  the  upper  bicuspkls  and 
molars.  It  will  be  observed  the  line  of  holes  is  not  parallel  with  the 
upper  edge. 

Fig.  164.  Fio.  165.  Fiu.  166. 

11"         y^  A 


For  central  incisors. 


For  ui»i»er  bicuspids  and 
molars. 


For  lower  bicuspids  and 
molars. 


Fig.  167. 


For  lower  front  teeth. 


Fig.  166  shows  the  arrangement  for  the  l(yu:!er  bicuspids  and  molars. 
Here,  too,  the  line  of  holes  is  not  parallel  with  the  edge,  to  allow  for 
the  difference  in  distance  from  the  commissure  of  the  lips  to  the  ante- 
rior and  posterior  holes. 

Fig.  167  shows  the  arrangement  when  the  lower  incisors  and  canines 
are  included.  Here  the  line  of  the  apertures 
is  curved. 

Rv  conforming  to  these  arrangements  of 
tlu>  openings  in  the  rubber,  and  by  extend- 
ing the  line  in  conformity  with  it,  as  well  as 
l)y  increasing  the  size  of  the  piece,  any  num- 
ber of  holes  may  be  made,  to  include  any 
portion  or  all  of  the  teeth  of  one  cpiarter  of 
the  denture  when  that  may  be  re(inired. 

The  number  of  a])ertures  in  the  rubl)er  should  l)e  such  as  to  give 
easy  access  to  the  o])eratiou  and  to  permit  the  free  entrance  of  light. 
For  the  anterior  teeth  five  to  si.\  holes  are  necessary,  and  for  the  pos- 
terior teeth  from  four  to  si.x  as  may  be  needed  to  secure  the  al)Ove-stated 
objects.  In  general,  at  least  tw^j  teeth  anterior  to  the  one  operated 
upon,  and  when  admissible  the  one  posterior,  should  be  included. 

The  Placement  of  the  Dam. — When  the  teeth  are  not  in  firm  con- 
tact or  when  their  attachments  are  flexible  the  adjustment  of  the  dam 
is  simple.  But  when  the  teeth  are  rigid  certain  preliminary  conditions 
should  be  secured.  It  has  been  pointed  out  in  speaking  of  the  prepara- 
tion of  the  teeth  for  a  series  of  op(>rations  that  they  should  be  well 
cleaned  of  any  deposits  which  may  be  upon  them  and  be  poli.'^hed  on 
their  approximal  surfaces.  This  makes  easier  the  insertion  and  the 
application  (tf  the  rubber. 


USE  OF  RUBBER  DAM.  203 

Generally  where  the  case  under  treatment  is  an  approximal  surface 
the  necessary  preparatory  separation  makes  easy  the  immediate  open- 
ing of  any  interstices  near  the  operation.  In  cases  of  extreme  fixa- 
tion of  the  teeth  a  piece  of  rubber  dam  placed  for  a  day  or  so  in  a 
couple  of  the  neighboring  spaces  makes  it  easy  to  enter  the  margin  of 
the  interstices.  The  passage  of  a  silver  tape  with  a  little  benne  oil  or 
cosmolin  on  it  often  answers  as  an  equivalent  means.  In  the  front 
teeth  a  thin  wedge  inserted  just  above  a  tight  point  permits  an  easy 
entrance. 

The  preliminary  silking  of  the  adjoining  spaces,  particularly  if  the 
silk  be  coated  with  cosmolin  or  its  equivalent,  also  facilitates  the 
passage  of  the  rubber,  and  for  this  purpose  soaping  the  under  surface 
of  the  rubber  adjacent  to  the  holes  is  recommended. 

At  first  the  novice  finds  difficulty  in  making  application  of  the  dam, 
but  practice  cultivates  facility.  In  general  it  is  better  to  commence 
with  the  anterior  hole  and  proceed  posteriorly  until  all  the  intended 
teeth  are  included.  Thus  for  the  left  lower  teeth  the  rubber  is  taken 
with  the  index  fingers  applied  to  the  upper  surface,  the  other  fingers  to 
the  under  surface,  and  is  grasped  near  the  hole  for  the  front  bicuspid  ;  the 
hole  is  extended ;  the  edge  of  the  rubber  is  inserted  in  the  mesial  inter- 
stice and  is  carried  down  to  the  gum.  It  is  then  drawn  over  the  tooth 
and  passed  into  the  next  interstice  in  the  same  manner.  This  method 
is  pursued  with  each  tooth  until  all  are  included.  The  passage  of  the 
rubber  is  facilitated  by  helping  it  downward  by  the  insertion  of  floss 
silk,  which  is  held  taut,  and  with  a  firm  and  gently  sliding  movement 
the  rubber  is  conveyed  toward  the  cervix. 

When  the  most  distant  tooth  is  the  lower  third  molar,  it  is  generally 
best  when  the  cavity  is  on  either  side  of  the  last  interstice  to  pass  the 
jaws  of  a  dam  clamp  through  the  posterior  hole  ;  the  clamp  is  then  made 
to  grasp  the  tooth,  the  dam  is  conveyed  to  the  gum  by  silking,  and  the 
adjustment  is  then  carried  forward  from  tooth  to  tooth.  The  same  pro- 
cedure is  sometimes  applicable  with  short  third  molars  in  the  upper 
denture,  or  in  case  any  of  the  posterior  teeth  are  so  shaped  as  not  to 
retain  the  rubber. 

When  the  rubber  is  adjusted  over  the  teeth  the  purpose  of  the  dam 
is  effected  by  directing  the  edge  of  the  dam  under  the  free  margin  of 
the  gum.  This  is  done  by  passing  a  silk  thread  around  the  tooth,  and 
crossing  the  ends,  when  by  a  drawing  movement  of  the  thread  it  travels 
down  the  inclined  surface  of  the  cervix,  carrying  the  dam  with  it,  thus 
making  a  more  secure  formation  of  the  valve. 

This  method  avoids  the  needless  paining  of  the  patient  caused  by 
pushing  the  threads  against  the  gum  with  instruments.  Whenever 
necessary  for  securement  the  ligature  should  be  tied.     This  should  be 


204  EXCLUSION  OF  MOISTURE. 

done  to  the  teeth  on  both  sides  of  an  iipproxinud  cavity.  Jt  is  neces- 
sary here  to  place  the  cervical  margin  of  the  cavity  in  full  view  and  to 
make  certain  the  exclusion  of  moisture,  which  otherwise  might  pass  the 
valve  by  capillary  attraction. 

The  ligature  should  usually  be  passed  but  once  around  the  tooth  and 
then  be  tied  with  a  surgeon's  knot,  the  place  of  the  knot  being  on  the 
outside.  \Mion  there  is  much  strain  the  thread  may  be  passed  twice 
around  the  tooth,  but  this  shoidd  be  avoided  as  being  more  painful  and 
as  increasing  the  bulk  of  the  ligature. 

To  prevent  the  rubber  from  displacement  by  the  movement  of  the 
cheeks  on  the  posterior  teeth  when  they  are  long,  if  after  drying  the 
surface  a  little  sandarac  or  damar  varnish  is  applied  at  the  last  inter- 
stice, the  rubber  becomes  fixed. 

In  cavities  extending  above  the  cervix  where  a  ligature  cannot  be 
placed  above  the  cervical  border  of  the  cavity,  other  means  have  to  be 
adopted  to  obstruct  the  entrance  of  fluids.  Here  the  strait  of  rubber 
between  the  holes  should  be  much  wider  than  usual ;  the  abundant  fold 
may  then  be  forced  beyond  this  margin  with  a  matrix,  when,  by  drying 
the  parts  and  by  the  deft  introduction  of  alcohol  varnish  and  suitable 
wedges,  dryness  of  the  parts  is  attained.  In  the  most  extreme  cases  of 
this  nature  the  part  beneath  the  normal  gum  line  may  be  filled  with 
a  permanent  plastic  substance,  as  described  in  the  section  on  Lining 
Cavities  (see  Chapter  IX.,  p.  218). 

The  Securement  of  the  Dam  from  Displacement. — When  the 
teeth  are  short  from  incomplete  development  or  when  their  form  is 
tapering  from  the  gum  toward  the  occlusal  aspect  there  is  always  ten- 
dency of  the  rubber  to  escape,  and  the  contraction  of  the  commissure 
of  the  lips  tends  to  the  displacement  of  the  dam  at  the  posterior  teeth, 
the  latter  movement  often  being  sufficient  to  overcome  the  friction  of 
the  ligatures.     When  these  difficulties  arise  a  clamp  is  required. 

The  Clamp. — This  is  an  instrument  of  much  value  not  only  as  a 
means  of  securement  of  the  rubber,  but  as  an  adjunct  to  prevent  the 

Fig.  168.  Fig.  169. 


Dr.  Southwick's  clamps.  Dr.  Uuey's  clamps. 


rubber  from  obstructing  the  view.  Clamps  are  more  especially  needed 
to  detain  the  rubber  on  the  molars  and  are  rarely  required  for  the  bicus- 
pids or  the  anterior  teeth,  since,  if  the  foregoing  directions  are  followed, 
the  necessity  for  their  use  will  l)ut  seldom  be  presented. 


USE  OF  RUBBER  BAM. 


205 


Forms  of  Clamps. — For  the  molars  various  sizes  and  shapes  of  the 

"  Southwick  "  and  of  the  "  Huey  wisdom-tooth  clamp  "  are  sufficient 

for  general  use.     In  addition  to  these  "  Palmer's  set  of  eight,"  after 

the  sharp  points  of  the  jaws  are  rounded,  will  furnish  the  requisite 

variety. 

Fig.  170. 


Dr.  Delos  Palmer's  set  of  eight  clamps. 

The  Application  of  the  Clamp. — The  selected  clamp  is  extended 
by  the  clamp  forceps  to  enable  it  to  pass  over  the  molar.  It  is  con- 
veyed to  the  middle  portion  of  the  tooth,  when  the  inner  beak 
should  be  brought  against  the  tooth  at  the  gum  margin ;  then  with 
this  point  as  a  fulcrum  the  outer  beak  is  carried  to  the  cervix  on  the 
buccal  sm-face.  Much  pain  may  be  avoided  in  the  employment  of 
this  appliance  by  deft  and  careful  placement.  Injury  of  the  gum  and 
needless  pain  has  frequently  been  inflicted  by  careless  use  of  force  in 
the  application  of  this  appliance.  Much  of  this  may  be  avoided  by 
the  previous  ligation  of  the  tooth,  which  will  prevent  the  tendency  of 
the  clamp  to  descend  beneath  the  gum  when  the  necks  of  the  teeth 
are  much  inclined  inward. 

When  it  is  necessary  to  force  the  clamp  against  the  soft  tissues  the 
previous  application  of  a  solution  of  cocain  will  obtund  the  tissue  and 
render  the   application  tolerable. 

The  Arrangement  of  the  Dam  on  the  Pace. — This  concerns  the 
convenience  of  the  operator  and  the  comfort  of  the  patient.  To  give 
easy  access  and  permit  the  entrance  of  light,  the  rubber  is  drawn  aside 
at  each  upper  corner  by  dam-holders.  The  simpler  forms  of  these  are 
sufficient  and  are  more  convenient  than  the  more  complicated  ones  when 
triangular  pieces  of  rubber  are  employed.  In  addition  a  supporter, 
shown  at  Fig.  172,  passes  over  the  head  and  engages  at  each  end  with 
the  holder.  The  comfort  of  the  patient  is  secured  by  including  a  nap- 
kin along  with  the  rubber  in  the  clasps  of  the  holder.  The  excess  of 
the  rubber  at  each  side  should  be  taken  up  in  a  fold  and  secured  to  the 


206 


EXCLUSIOX  OF  MOISTURE. 


napkin  hv  (Irossini:  pins.     Tlu^  suspended  part  of  the  nihlxT  is  kept 
taut  by  ])on(l('nt   weights. 

Tlie  a])])lieati()n  and  arrangement  of  the  dam  becomes         Kkj.  172. 
bv  practice  a  very  sim]ih^  matter,  and  slioiild   not  be  the 
occasion  of  discomfort  or  pain  to  the  patient. 

Fig.  171. 


Design  of  Dr.  Cogswell. 


A  s\iii))()rter. 


The  Use  of  Napkins. — There  are  many  instances  of  simple  cases  in 
accessible  jjositions  not  of  approximal  surfaces,  when  the  general  flow 
of  saliva  can  be  kept  under  control  by  the  saliva  ejector,  where  it  is  not 
necessary  to  use  a  rubber  dam.  Also  for  children, when  the  teeth  are 
too  short  to  ])ermit  the  correct  a])plication  of  the  dam,  it  is  necessary  to 
find  other  means  to  control  the  moisture.  Here  the  reliance  is  upon 
napkins,  and  \\  ith  them  much  skill  may  be  <lis])layed  by  deft  operators. 
For  this  ])urpose  the  iiajjkiu  should  not  be  over  eight  inches  scpiare. 
The  manner  of  folding  is  to  carry  two  adjacent  edges  to  the  diagonal 
of  the  napkin,  and  then  fold  again  in  like  manner;  by  this  plan  the 
folds  are  held  in  j)laee. 

To  apply  a  napkin  to  the  upper  right  side,  the  point  is  taken  between 
the  left  index-finger  and  the  thumb,  the  broad  end  being  held  at  the 
same  time  by  the  right  hand.  The  lip  near  the  right  commissure  is 
everted,  the  point  is  inserted  here,  and  by  the  taut  action  of  the  left 
hand  the  napkin  is  next  laid  between  the  gum  and  the  lip.  It  is  then 
carried  backward  until  it  reaches  the  duct  of  Steno,  when  the  left  index 
finger  is  applied  to  maintain  the  compression  at  this  latter  point.  The 
free  end  of  the  napkin  lies  upon  the  lower  lip.  For  the  left  side  the 
action  is  the  same  by  the  reversal  of  the  hands. 

For  the  lonrr  teeth  the  application  differs  by  commencing  for  each 
side  at  the  upper  canine  of  that  side.  "When  the  duct  of  Steno  is 
reached  a  fold  is  made  to  eifect  the  compression  of  the  orifice  of  the 
duct,  then  the  napkin  is  laid  between  the  cheek  and  the  lower  teeth 
and  kept  in  position  by  the  left  index-finger,  a  mirror,  or  a  check- 
holder. 


USE  OF  RUBBER  DAM. 


207 


An  important  preliminary  to  the  application  of  a  napkin  to  these 
positions  is  that  the  saliva  ejector  be  first  placed  in  action  and  that  the 
surfaces  of  the  gum  and  cheek  be  wiped  to  dryness,  to  cause  the  napkin 
to  cling  to  the  surface.  If  the  surfaces  are  covered  with  mucus  and 
at  the  same  time  are  wetted  with  saliva,  the  napkin  easily  becomes 
displaced. 

Aseptic  Napkins. — For  simple  procedures — such  as  dressings,  making 
examinations,  putting  in  temporary  stoppings  and  small  occlusal  fillings 
— the  recently  introduced  aseptic  napkins  are  very  useful.  They  are 
folded  into  triangular  shape.  The  evolution  into  this  form  is  shown 
by  Fig.  173. 

Fig.  173. 


In  the  completed  form  these  may  be  placed  in  any  convenient 
manner  to  assist  in  protecting  many  easy  cases  from  the  encroachment  of 
saliva.  Used  in  connection  Avith  absorbent  and  non-absorbent  rolls  they 
furnish  much  facility,  and  do  not  encumber  the  mouth  or  cause  distress. 
Fig.  174  shows  the  manner  of  applying  the  folded  aseptic  napkin,  where 
it  is  held  in  place  by  an  Ivory  clamp.     In  this  and  similar  cases  a  short 


Fig.  174. 


Fig.  175. 


piece  of  non-absorbent  roll  may  be  included  with  advantage  at  the  part 
opposite  the  duct  of  Steno,  Avhich  by  the  pressure  will  occlude  this  duct. 
Similar  means  may  be  followed  with  the  lower  teeth  by  placing  non- 
absorbent  rolls   as  appears  in  Fig.  175.     When  in  connection  with  an 


208  EXCLUSION   OF  MOISTURE. 

absorbent  roll  to  occlude  the  jxirotitl  duct,  uncomplicated  occlu.<al  cases 
are  carried  on  with  facility.  Hence  it  will  appear  the  field  of  work  may 
be  upon  any  of  the  teeth  within  the  limits  of  the  rolls. 

NAUSEA. 

The  contact  of  rubber  dam  witii  the  tonp;ue  and  the  contiguous  parts, 
the  jiresence  of  napkins,  and  the  touch  of  the  fingers  to  the  oral  surfaces 
frequently  excites  naiisai.  AVith  some  persons  this  kind  of  distress  is 
extreme  and  produces  simulation  of  faintness  and  nervousness.  This 
condition  may  generally  be  relieved  by  the  use  of  (Kjna  cdinphora,  a  few 
drachms  being  used  as  a  gargle  to  the  mouth  antl  the  throat.  When 
indications  of  faintness  appear  a  drachm  may  be  swallowed  with  imme- 
diate benefit. 

In  case  excessive  nausea  is  occasioned  by  the  contact  of  the  appli- 
ances with  the  tongue  or  palate,  these  surfaces  may  be  painted  with 
tincture  of  camphor.  Spasmodic  coughing,  not  infrequent  with  nervous 
persons,  yields  to  the  same  treatment.  Camphor  appears  to  relieve  in 
these  instances  by  its  antispasmodic  power,  and  it  is  stated  to  have  also 
a  specific  action  upon  the  eighth  pair  of  nerves. 

Nervousness  coming  on  during  any  of  the  operations  upon  the  teeth 
may  as  easily  and  in  the  same  manner  be  avoided.  It  will  be  oi)serve(l 
that  in  neither  of  these  conditions  are  the  first  signs  of  approaching 
syncope  apparent,  viz.  sighing  respiration,  pallor,  and  clammy  perspi- 
ration of  the  face. 

A  condition  somewhat  simulating  approaching  syncope  sometimes 
appears  in  connection  with  the  use  of  the  rubber  dam,  due  to  ])artially 
suspended  respiration,  which  is  caused  not  so  much  by  the  obstruction 
of  the  mouth  as  by  the  unpleasant  sensations  occasioned  by  the  appli- 
cation and  presence  of  the  dam.  This  may  at  once  be  overcome  by 
requesting  the  patient  to  breathe  deeply  through  the  nose. 


CHAPTER    IX. 

THE  SELECTION  OF  FILLING  MATERIALS  WITH  REFER- 
ENCE TO  CHARACTER  OF  TOOTH  STRUCTURE,  VARIOUS 
ORAL  CONDITIONS  AND  LOCATION,  DEPTH  OF  CAVITY 
AND  PROXIMITY  OF  THE  PULP— CAVITY  LINING,  WITH 
ITS  PURPOSES. 

By  Louis  Jack,  D.  D.  S. 


The  general  object  in  view  in  the  filling  of  a  prepared  cavity  is  to 
secure  the  future  preservation  of  the  tooth  at  that  part  from  the  recur- 
rence of  caries.  This  involves  a  consideration  of  the  character  of  the 
material  to  be  used,  in  relation  to  its  adaptability  to  the  conditions  of 
age,  the  quality  of  the  teeth,  and  the  oral  conditions  which  for  the  time 
are  an  expression  of  the  general  state  of  the  organism.  The  habits  of 
the  patient  as  to  general  care  of  the  teeth  also  have  some  bearing  upon 
the  probability  of  permanence  of  the  reparative  operation.  A  material 
adapted  to  preserve  the  teeth  when  they  are  of  resistant  quality  and 
when  the  general  health  is  sound  and  the  care  good,  may  be  out  of 
place  when  the  opposite  conditions  exist.  Methods  of  procedure  have 
some  bearing  upon  the  result,  and  the  influence  of  these  has  also  to  be 
kept  in  view. 

The  general  characteristics  of  the  material  to  be  used  as  a  pre- 
servative of  tooth  structure  are  of  importance  in  the  following  order : 

Resistance  to  chemical  action  ; 

Capability  of  adaptation  to  the  surface  of  the  cavity ; 

Sufficient  hardness  to  withstand  the  force  of  mastication  and  the  con- 
sequent attrition. 

Capability  of  form  and  smoothness  are  also  important  in  relation  to 
cleanliness,  which  more  than  any  other  indirect  influence  has  the  greatest 
bearing  upon  the  preservation  of  the  margins  from  subsequent  softening, 
as  will  further  appear. 

The  Materials. 

The  various  accepted  materials  in  use  are  :  gold,  tin,  amalgams,  the 
basic  oxid  cements,  gutta-percha. 

The  first  three  named  may  be  designated  as  permanent  in  their  cha- 
14  209 


2 1 0  I'll- 1- ry< '  M. I  tj:h 1. 1 Ls. 

vacttT,  and  the  otluTs  as  ot"  a  tciiipoiary  iiatiu'c,  wliicli,  after  fulfilling; 
ini])ortant  uses  in  this  way,  an-  (tftcn  j)ri'})arat()ry  to  later  and  ])eniianent 
treatment. 

Gold. — The  properties  (»t"  j^old  which  a(la])t  it  for  the  restoration  of 
carious  teeth  are  its  pliahility  and  softness,  which  permit  its  adaptation 
to  the  form  of  the  cavity  ;  its  tenacity,  which  ijives  facility  of  introduc- 
tion and  const)lidation  ;  and  its  agreeableness  of  color,  which,  when  the 
surface  is  solid,  smooth,  and  unburnished,  approaches  more  nearly  the 
shade  of  the  teeth  than  any  other  metal. 

Xotwith.standing  these  appro})riate  ijualities  the  packing  of  gold 
requires  the  employment  of  considerable  force  to  overcome  various 
resistances  to  its  adaptation  and  solid  condensation.  To  effect  the 
requisite  degree  of  density  percussive  force  frecpiently  becomes  necessary. 
The  effect  of  percussive  force,  if  employed  throughout,  is  liable  to  be 
expended  on  the  margin  toward  which  it  is  directed,  and  while  this  may 
not  inflict  any  injury  upon  the  borders  of  cavities  when  the  dentin  and 
enamel  are  dense,  it  often  proves  injurious  to  teeth  when  the  anatomical 
elements  of  the  structure  are  not  homogeneous  and  resistant. 

While  it  may  be  stated  with  the  strongest  assurance  that  gold  pos- 
sesses the  highest  preservative  qualities  and  promises  greater  durabil- 
ity and  more  satisfactory  results  than  any  other  material,  conditions 
are  often  presented  when  to  persist  in  its  use  would  lead  to  unsatis- 
factory results;  thus,  in  the  approxiraal  cavities  of  the  teeth  of  children, 
when  the  calcifying  process  has  not  become  complete  and  when  by  the 
use  of  the  required  force  some  impairment  of  the  incomplete  tissues  is 
almost  certain  to  ensue.  The  same  maladaptability  occurs  later  in  life 
when  senile  conditions  have  set  in,  when  the  teeth  not  only  have  lost 
their  density  from  the  ])eculiar  molecular  changes  which  take  place 
in  the  dentin  and  enamel,  but  when  usually  also  their  resistance  to 
chemical  infiuences  is  greatly  impaired.  These  conditions,  coupled  with 
the  usual  inability  to  properly  care  for  the  teeth,  render  the  use  of  gold 
very  questionable. 

Similar  states  of  the  dental  tissues  take  place  in  middle  life  in  both 
sexes,  but  more  particularly  in  women  during  the  pregnant  state, 
when  the  teeth  lose  their  resistant  power,  Avhich  may  later  be  restored. 
While  this  condition  lasts,  materials  requiring  less  force  should  be 
selected  until  restoration  of  resistance  has  occurred. 

The  mode  of  effecting  percussion  should  be  taken  into  account  in 
estimating  the  influences  which  bear  against  the  use  of  gold.  When 
percussion  is  effected  by  the  electro-magnetic  instruments  with  proper 
precautions  with  respect  to  the  placement  of  the  first  portions  of  gold, 
there  is  less  danger  of  marginal  injury  than  when  percussion  is  made 
with  the  hand  or  the  automatic  mallet, 


GOLD— TIN.  211 

Finally,  the  fact  must  also  be  recognized  that  in  cases  in  which  the 
character  of  the  structure  of  the  teeth  raises  a  question  as  to  the  adap- 
tability of  gold,  the  physical  and  nervous  reaction  of  the  patient  is 
generally  below  that  which  would  enable  him  to  endure  the  ordeal 
connected  with  the  thorough  completion  of  the  work  in  harmony  with 
the  high  standard  impressed  by  the  continued  advancement  which  has 
taken  place  in  dentistry. 

The  tendency  to  caries  of  the  teeth  is  a  general  consideration  to 
be  held  in  view  in  determining  the  propriety  of  employing  gold. 
When  the  enamel  is  hard,  the  dentin  solid,  and  the  general  tone  of 
the  health  excellent,  there  can  be  no  doubt  that  the  inherent  qualities 
of  gold  constitute  it  the  most  nearly  permanent  material.  When,  on 
the  contrary,  the  opposite  conditions  exist,  gold  becomes,  in  propor- 
tion to  the  prominence  of  the  unfavorable  states  present,  the  most 
questionable  material. 

No  correct  conclusion,  however,  can  be  reached  without  consideration 
of  the  state  of  the  oral  secretions  and  of  the  habits  of  the  patient  as 
to  the  care  taken  of  the  mouth.  The  first  stage  of  decay  of  the  teeth 
is  the  softening  of  the  enamel,  which  is  brought  about  as  the  conse- 
quence of  the  presence  of  carbohydrates  undergoing  fermentation  in 
secluded  positions,  which  effects  the  solution  of  the  enamel  at  these 
places  and  prepares  the  way  for  the  occurrence  of  caries  of  the  dentin. 
Hence  a  correct  hygienic  condition  of  the  mouth  is  the  most  important 
requirement  for  the  protection  of  the  margins  of  the  tooth  adjacent  to 
fillings  intended  to  restore  them. 

The  reaction  of  the  oral  secretions  in  their  bearing  upon  the  permanence 
of  dental  operations  has  also  much  weight,  since,  when  these  secretions 
have  an  acid  reaction,  as  the  consequence  of  the  presence  of  fermenting 
material,  this  condition  favors  the  continuance  of  the  process.  A  con- 
tinual acid  state  of  the  oral  fluids,  as  a  consequence  of  derangements  of 
health  such  as  occur  in  impaired  digestion  or  attend  the  rheumatic 
diathesis,  should  be  taken  into  account.  Only  an  appreciable  degree 
of  alkalinity  can  inhibit  enamel  solution  unless  the  general  and  local 
hygienic  conditions  are  favorable. 

Tin. — This  metal,  in  the  form  of  foil,  shavings,  and  rolled  into 
thin  strips,  while  not  in  much  use,  should  have  a  wider  field  than  is 
accorded  it.  It  possesses  great  softness,  when  chemically  pure,  and 
is  readily  adapted  to  the  walls  of  cavities  for  the  reason  that  it  pre- 
sents less  resistance  since  it  does  not  harden  under  the  mechanical  force 
employed.  For  the  same  reason,  when  the  cavity  is  overfilled,  the  con- 
densing appliances  effect  by  the  lateral  movement  of  the  mass  a  better 
and  more  easily  procured  adaptation  with  the  cavity  walls.  For  these 
reasons  it  possesses  excellent  preservative  qualities. 


212  FILLING    MATERIALS. 

Tin  is  also  a  poorer  thermal  conductor  than  pold,  and  this  is  an 
important  consideration  when  thermal  irritation  is  to  be  avoided,  and  is 
of  great  value  in  deep  cavities  approaching  dangerously  near  to  the  pulp. 

The  objections  to  this  metal  are  its  color  when  exposed  to  view  and 
its  softness,  which  greatly  lessens  its  value  in  positions  where  it  may  be 
subject  to  severe  attrition. 

Its  most  important  use  is  for  the  temporary  teeth  (tf  children,  where 
it  may  be  easily  inserted  and  readily  condensed,  and  rapid  ^irogress  in 
its  introduction  may  be  made,  producing  good  results. 

Except  when  freshly  prepared,  tin  is  not  cohesive,  a  quality  which 
cannot  be  restored  by  heat,  as  may  be  done  with  gold. 

AMALGAMS. 

Their  Composition. — The  essential  metals  which  enter  into  the  com- 
position of  the  dental  amalgams  are  silver,  tin,  and  mercury.  To 
these  are  added  various  metals  in  varying  proportions  to  modify  the 
"  setting,"  the  color,  and  the  affinity  for  sulfur  compounds.  For  these 
purposes  gold  is  used  to  influence  the  rate  of  chemical  combination,  and 
it  also  affects  the  color.  Zinc  and  copper  are  added  in  order  to  modify 
the  shade  and  also  to  lessen  the  affinity  for  sulfur. 

The  effect  of  various  proportions  of  the  metals  entering  into  the 
formulas  upon  the  working  qualities  of  an  amalgam  is  extremely  puz- 
zling ;  slight  differences  in  proportions  causing  widely  varying  results. 

The  order  in  which  the  metals  are  introduced  into  the  crucible  and 
the  degree  of  heat  to  which  the  mass  is  subjected  in  the  fusing  process 
also  affect  the  working  qualities. 

The  Proportion  of  the  Ingredients. — Valuable  tables  have  been  given 
by  Dr.  Black  which  indicate  that  a  nearly  definite  ratio  between  the 
silver  and  tin  should  be  maintained.  This  ratio  is  found  to  be  approxi- 
mately as  follows — Silver  65,  Tin  35 — when  only  these  two  metals  are 
used  to  make  the  alloy.  Whatever  addition  of  a  modifying  metal  is 
introduced  should  be  of  small  quantity  and  at  an  equivalent  reduction 
of  the  percentage  of  the  tin. 

The  ingot  of  the  alloy  should  be  finely  divided  either  by  filing  or  by 
thin  shavings  made  by  turning  them  off  in  a  lathe.  When  the  commi- 
nution of  the  alloy  is  made  immediately  before  using,  amalgamation  is 
more  easily  effected  than  when  the  filings  are  kept  for  any  considerable 
time,  unless  in  the  latter  case  there  is  a  disproportion  of  tin  or  gold. 
This  has  been  attributed  to  oxidation  of  the  particles  taking  place,  which 
would  retard  the  amalgamation.  Silver  not  being  an  oxidizable  metal 
under  ordinary  conditions,  the  cause  of  the  tardy  combination  with 
mercury  is  to  be  found  in  the  attachment  of  sulfids  to  the  surface,  and 
also   to   the  influences  of  occluded   gases,  which  also  tend  to  retard 


AMALGAMS.  213 

amalgamation.  It  is  a  notable  fact  that  while  freshly  comminuted  alloy 
will  more  readily  amalgamate,  it  requires  more  mercury  than  aged 
alloy. 

More  recent  investigations  by  Dr.  Black  tend  to  the  conclusion  that 
the  difference  in  capacity  for  mercury  observed  m  freshly  cut  alloy  and 
that  which  has  been  cut  for  some  time  is  due  to  the  difference  in  molec- 
ular arrangement  of  the  alloy,  brought  about  by  the  comminuting  pro- 
cess, Avhich  has  the  effect  of  hardening  the  grains  and  condensing  their 
texture  in  the  same  manner  that  hammering  the  ingot  would  harden  the 
entire  mass.  By  the  application  of  sufficient  heat  the  particles  of  alloy 
may  be  "  aged  "  artificially,  and  this  aging  is  presumed  to  be  simply  an 
annealing  process.  The  capacity  of  the  aged  alloy  for  mercury  is 
markedly  different  from  that  of  the  freshly  cut  alloy,  as  are  also  the 
working  qualities  of  the  resulting  amalgam  mass,  the  aged  alloy  form- 
ing a  slower  setting  and  much  smoother  working  amalgam  than  that 
made  from  freshly  cut  alloy.  For  the  further  details  of  this  subject 
see  Chapter  XIII.,  on  Plastic  Fillings. 

It  is  held  by  many  that  the  proportion  of  mercury  should  be  in  some 
excess,  to  give  decided  plasticity  to  the  mass  for  the  purpose  of  securing 
complete  amalgamation  of  the  particles  of  the  alloy.  When  the  amal- 
gamation is  complete  the  redundance  is  forced  out  through  chamois 
skin,  or  the  mass  is  kneaded  in  a  napkin  or  piece  of  China  silk,  which 
forces  through  the  meshes  most  of  the  excess.  It  is  claimed  that  this 
method  of  conducting  the  amalgamation  effects  an  approximately  cor- 
rect atomic  relation  of  the  metals  with  each  other ;  it  being  held  that 
the  freer  proportion  of  mercury  during  the  mixing  process  tends  to  this 
result,  as  the  redundant  metal  is  carried  out  with  the  excess  of  mercury 
as  it  is  expressed.  On  the  other  hand,  it  is  maintained  that  the  propor- 
tions of  any  given  alloy  and  mercury  which  will  produce  an  amalgam 
fulfilling  every  requirement  should  be  established  by  experimentation, 
and  thereafter  be  weighed  out  in  those  proportions. 

The  Distinguishing  Features  of  a  Good  Amalgam. — An  amalgam  (1) 
Should  be  non-shrinking ;  (2)  Should  have  edge  strength ;  (3)  Should 
maintain  lightness  of  color  under  the  varying  oral  conditions.  A  further 
qualification  is  that  the  surfaces  of  the  material  may  not  undergo  elec- 
trolysis. 

Indisposition  to  shrinkage  is  secured  by  a  close  conformity  of  the 
alloy  with  the  jDroportions  above  given. 

Edge  strength  is  a  term  which  has  not  as  yet  had  a  clear  defini- 
tion in  respect  to  the  causes  which  determine  the  deficiency  of  this 
quality.  The  maintenance  of  unchangeability  of  the  surface  is  directly 
related  to  this  important  desideratum,  as  roughening  and  erosion  of  the 
margins  is  the  result  of  molecular  waste,  which  causes  a  ragged  and 


•Jit  in  A.  I  Ml    M.\TKRI.\I.S. 

iiiu'lcan  :ij)j)t'aranft'  oi'  the  cdiit's  mid  an  a|i]>ar('nt  sc])ai'atinii  uf"  tlic  lill- 
iiiij  from  the  borders  of  tin-  cavity.  Tlic  causes  ^vllicIl  jtrodiicc  this 
condition  are  slowly  ])roj>;rossivo  and  arc  continuous. 

This  kind  of  erosion  is  most  marked  when  contraction  takes  place, 
from  ineorreet  preparation  or  improper  ratio  of  the  metals  entering 
into  the  formula,  or  careless  manipulation,  when  capillary  defects  are 
liable  to  oeenr  at  the  mar(2:ins. 

The  most  probable  hyjK)thesis  to  account  for  these  observed  changes 
is  that  the  presence  of  moisture  having  acitl  reaction,  by  inducing  elec- 
trolvtic  action  between  the  imperfectly  combined  metals,  brings  about  the 
erosion  of  the  material  immediately  within  the  margins.  In  these  eases  the 
exposed  surfaces  generally  suffer  little  waste,  for  the  reason  that  they 
are  subject  to  the  continued  movement  of  the  oral  fluids,  but  it  is  often 
observed  that  entire  fillings  undergo  a  similar  gradual  loss  and  disappear. 
This  result  is  common  where  there  is  an  excess  of  gold  or  mercury.  In 
some  instances  the  above  descril)ed  action  takes  place  to  a  limited  degree 
upon  the  whole  surface  in  proximity  with  the  dentin,  when  a  residue 
is  found  upon  the  filling  as  well  as  on  the  surface  of  the  dentin. 

The  conclusion  from  these  observed  facts  is  that  the  secin*ement  of 
edge  strength  depends  upon  an  approximation  to  the  chemical  ratio  of  the 
elements  of  the  alloy.  This  would  apjiear  to  be  most  nearly  secured 
when  the  material  is  subject  neither  to  shriidvage  nor  expansion.  Ex])an- 
sion  under  some  circumstances  might  ])roduee  marginal  space  and  there- 
fore lead  to  the  same  result  ;  for  instance,  if  in  apj)roxinial  or  buccal 
cavities  the  depth  were  greater  at  one  division  than  another  the  expan- 
sion of  the  thicker  ])art  of  the  filling  wo^uld  tend  to  raise  the  edge  sur- 
rounding the  shallow  part  of  the  cavity,  and  would  then  subject  the 
edge  of  the  filling  to  electrolytic  changes. 

A  related  condition  sometimes  appears  when  an  amalgam  filling, 
quite  hard  at  completion,  after  some  years  becomes  comparatively  soft, 
which  apparently  is  due  to  molecular  changes. 

The  close  conformity  of  the  alloy  to  the  proportions  recently  estab- 
lished by  Black,  and  anticipated  by  the  much  earlier  experimentation 
of  Flagg,  furnishes  a  result  that  is  directly  conducive  to  fixity  of  form 
and  edge  strength  when  the  margins  of  the  cavity  are  overlapped. 

This  formula  is  a]i])roximately — silver,  68  ;  tin,  26  ;  copper,  5  ; 
zinc,  1. 

The  maintenance  of  size,  form,  and  strength  depends  largely,  if 
not  entirely,  u])on  the  influence  of  silver.  When  the  proportion  of 
this  element  becomes  less  than  60  ])er  cent,  of  the  formula, the  tendency 
to  shrinkage  appears  and  holds  a  nearly  direct  relation  with  the  diminu- 
tion. When  the  ratio  of  silver  "advances  above  70  per  cent,  the  expan- 
sion becomes  marked,  and  at  80  i)er  cent,  is  excessive. 


THE  MINERAL  CEMENTS.  215 

Lightness  of  Color. — The  means  by  which  this  property  may  be 
secured  have  not  as  yet  been  well  determined  and  should  be  the  sub- 
ject of  extended  experimentation.  Some  of  the  so-called  white  alloys 
approximate  stability  in  this  respect,  but  the  ratios  of  the  modifying 
metal  have  not  been  accurately  determined. 

Amalgam  as  a  filling  material  is  adapted  to  large  cavities  in  the  pos- 
terior teeth  when  the  margins  are  too  frail  to  permit  gold  to  be  con- 
densed ;  for  positions  where  mechanical  force  cannot  be  exerted  with 
efficiency,  notably  the  cavities  of  the  third  molar ;  distal  cavities  of  the 
second  molar  when  of  large  size  ;  and  the  lingual  cavities  of  the  lower 
molars.  When  the  teeth  are  of  deficient  resistance  and  when  the  con- 
dition of  the  oral  secretions  favors  the  rapid  progress  of  caries  these 
limitations  may  be  extended  to  cavities  where  otherwise  gold  would 
appear  to  be  a  more  suitable  material. 

As  a  material  for  the  filling  of  the  deciduous  teeth  amalgam  possesses 
superiority  over  any  other  substance,  for  the  reasons  that  it  can  be  intro- 
duced with  less  effort  than  tin  and  has  greater  durability  than  either 
the  mineral  cements  or  gutta-percha  preparations  ;  the  exception  to  its 
use  here  being  when  the  conditions  prevent  retentive  formation  of  the 
cavity. 

Concerning  the /orm  of  the  caviti/  adapted  to  amalgam,  it  is  necessary 
that  the  retentive  formation  be  equally  exact  as  for  gold,  since  many 
of  the  formulas  in  use  undergo  slight  movement  for  some  time  after 
their  introduction,  during  which  there  is  liability  of  marginal  displace- 
ment which  may  lead  to  the  defects  treated  of  under  the  section  con- 
cerning "  edge  strength."  Amalgam,  while  presenting  in  its  appear- 
ance an  unfavorable  comparison  with  gold,  is  capable  of  rendering 
important  service  when  every  consideration  is  given  to  the  require- 
ments governing  its  successful  employment. 

To  attain  the  best  results  in  the  use  of  the  amalgams  requires 
extreme  exactness  as  to  the  ratios  of  the  ingredients  and  great  care  in 
all  the  procedures  connected  with  the  formation  of  the  cavity,  the  form 
of  the  filling,  and  the  subsequent  finishing  process. 

The  disqualifications  of  amalgam  are  its  unsatisfactory  color  and  the 
unknown  character  of  the  composition  of  the  formulas  as  furnished  by 
the  depots  of  supply. 

THE    MINERAL    CEMENTS. 

Oxychlorid  of  Zinc. — This  material,  because  of  its  lacking  the 
quality  of  indestructibility,  is  contraiudicated  in  all  exposed  situa- 
tions. It  possesses,  however,  a  considerable  degree  of  antiseptic  power, 
and  for  this  reason  renders  valuable  service  in  deep  cavities  not  nearly 
approaching  the  pulp,  or  even  here  when  the  pulp  wall  of  the  cavity 


216  FILLING   MATERIALS. 

has  been  })revi(tusly  protected  by  u  layer  oi"  gutta-pereha  or  a  disk  of 
asbestos  })aper.  In  such  cases,  particularly  on  occlusal  aspects,  the 
cavity  may  be  nearly  tilled,  leaving  a  remainder  the  thickness  of  enamel 
to  be  comjileted  Avith  o:(»l<l. 

For  the  filling  of  root  canals  and  pulp  cluunbers  it  offers  the  best 
solution  of  the  ])roblem  of  preventing  septic  changes  in  the  devitalized 
dentin.  After  many  years,  fillings  of  root  canals  and  pulj)  chambers 
of  this  material  remain  unchanged  and  are  found  clean  and  without 
odor  on  removal — a  result  that  is  not  presented  by  any  other  filling 
material  which  may  be  introduced  in  these  situations.  Here  it  is  im- 
portant that  the  material  be  not  mixed  very  thin,  esj)ecially  on  account 
of  the  danger  of  forcing  it  through  the  apical  foramen.  Poulson  chloro- 
zinc  cement  is  most  suitable  for  this  purpose,  since  it  mixes  with  a  creamy 
consistence  without  granulation. 

A  further  use  of  this  substance  is  to  influence  the  shade  of  devital- 
ized teeth  by  the  color  tone  it  imparts  to  the  crown  of  the  tooth  on 
account  of  its  whiteness.  This  is  enhanced  by  the  fact  that  it  comes 
into  exact  contact  and  remains  without  change,  a  quality  which  cannot 
be  given  to  gutta-percha  or  other  cements. 

As  a  temporary  filling  to  correct  extreme  sensitivity  of  dentin  in 
situations  or  under  conditions  which  forbid  ordinary  therapeutic  treat- 
ment, oxychlorid  of  zinc  has  considerable  value.  Here  when  the  pulp 
is  not  closely  a]i]U"oached  it  may  be  retained  for  several  months  with 
considerable  advantage.  To  secure  the  best  results  the  proportion  of 
zinc  chlorid  should  be  slightly  greater  than  in  the  formulas  used  for 
ordinary  fillings. 

Zinc  Phosphate. — This  material,  because  of  its  greater  power  to 
withstand  the  influence  of  the  oral  secretions,  has  a  wider  use  than  the 
previously  described  cement.  It  cannot,  however,  be  depended  upon 
for  permanent  uses.  While  in  some  instances  it  may  remain  for  several 
years  when  the  oral  fluids  are  neutral  and  when  every  attention  is  given 
toward  the  attainment  of  cleanliness,  it  is  nevertheless  a  deceptive  sub- 
stance, since  it  is  liable  under  temporary  changes  of  the  secretions  to 
undergo  solution,  more  particularly  in  situations  near  the  gum.  When 
placed  in  approximal  cavities  it  is  extremely  liable  to  become  fissured 
at  the  cervical  nuirgin  and  then  permit  carious  action  insidiously  to 
take  place. 

Unlike  oxychlorid  of  zinc,  the  phosphate  has  no  antiseptic  influence, 
hence  it  does  not  inhibit  decay  of  the  dentin  in  its  proximity.  Its  chief 
use  is  as  a  temporary  expedient  for  filling  cavities  on  labial  and  buccal 
surfaces,  w^here,  being  under  easy  observation,  it  nuiy  l)e  used  with 
benefit.  On  account  of  its  chemical  solution  by  the  oral  secretions, 
how^ever  slow  this  may  be,  it  requires  frequent  renewal. 


COMBINATION  OF  ZINC  PHOSPHATE   WITH- AMALGAM.        217 

Zinc  phosphate  is  also  of  value  for  filling  the  principal  portion  of 
large  compound  cavities  where  the  teeth  would  be  injured  by  the  force 
employed  in  the  condensation  of  gold,  and  as  a  desideratum  to  avoid 
the  great  amount  of  time  required  to  fill  large  cavities  with  this  metal. 
It  also  here  imparts  in  some  instances  much  strength  to  frail  margins. 

In  the  cavities  which  early  form  upon  the  occlusal  surfaces  of  the 
permanent  molar  teeth  of  children  it  is  of  great  value,  as  here  it  is  kept 
clean  by  the  friction  of  mastication,  and  being  under  easy  observation 
can  be  renewed  when  this  is  required.  When  the  child  reaches  the  age 
to  have  permanent  operations  the  margins  may  be  shaped  for  the  reten- 
tion of  gold,  and  in  this  case  the  principal  part  of  the  cement  may  be 
allowed  to  remain. 

Zinc  phosphate  is  of  questionable  use  in  pulp  chambers  as  not  hav- 
ing antiseptic  properties,  and  being  porous  it  becomes  after  several 
years  quite  oifensive.  For  the  same  reason  it  is  inadmissible  for  canal 
fillings.  Furthermore,  for  this  purpose  it  is  questionable,  on  account 
of  its  adhesiveness,  whether  it  is  capable  of  being  thoroughly  introduced 
into  root  canals.  All  things  considered,  it  is  for  these  purposes  greatly 
inferior  to  oxychlorid  of  zinc. 

Combination  of  Zinc  Phosphate  with  Amalgam. 

The  combination  of  a  mixed  amalgam  with  zinc  phosphate  is  made 
by  using  a  formula  of  alloy  containing  a  larger  proportion  of  zinc  than 
is  considered  above,  and  therefore  more  plastic  and  slower  in  setting.  The 
amalgam  mixture  is  made  and  combined  in  a  mortar  with  an  equal 
quantity  by  measure  of  zinc  oxide  by  careful  rubbing.  The  resultant 
powdery  mass  is  then  mixed  on  a  "  slate "  with  the  usual  phosphoric 
acid  to  a  stiff  paste,  when  it  is  inserted  in  the  prepared  cavity. 

The  condition  when  the  use  of  this  preparation  is  preferable  to 
ordinary  amalgam  is  where  the  form  of  the  cavity  is,  from  frailness  of 
margins  or  other  reasons,  not  admissible.  It  is  in  such  cases  better 
retained  by  the  adhesiveness  imparted  by  the  zinc  phosphate.  It  is  also 
well  adapted  for  temporary  purposes  as  being  little  subject  to  solution. 

Gutta-percha. — Compounds  of  gutta-percha  with  oxid  of  zinc  form 
a  useful  substance  for  temporary  fillings,  acceptable  for  teeth  of  low 
grade  at  points  not  subject  to  attrition.  Its  preservative  properties  are 
very  considerable,  and  were  it  not  subject  to  surface  degeneration  would 
in  the  situations  noted  be  a  nearly  permanent  material. 

The  requirements  for  its  successful  use  are  that  it  be  not  heated 
higher  than  212°  F.,  that  the  cavity  be  quite  dry,  that  it  be  intro- 
duced in  small  pieces,  and  be  he^t  under  continual  condensation  until 
cooled  to  prevent  shrinkage.     (See  Chapter  XIII.) 


218  FILLING  MATERIALS. 

Cavity  Lining  in  Respect  to  Proximity  of  the  Pulp. 

As  curies  ainn'onclics  the  pulp  it  readies  :i  pei-iod  when  the  proximity 
of  this  oriran  is  so  close  as  to  require  much  care  to  avoid  irritation  and 
prol)al)U'  contrestion.  Under  these  circnnistanees  it  is  necessary  to 
avoid  thermal  conduction  and  to  exclude  chemical  iiiHuences.  After 
disinfection  of  the  dentin  some  suhstance  the  intrrediency  of  which 
is  non-irritatintr  and  non-conductinn;  sh(»uhl  he  selected  to  overlay  the 
pulj)  wall  of  the  cavitv.  Here  choice  nuist  be  made  between  ^utta- 
jiercha  and  either  of  the  classes  of  mineral  cements. 

When  the  use  of  jrold  is  preferable  for  the  external  portion  of  the 
fillin<r,  it  is  required  that  tlie  foundation  be  sutticiently  solid  to  with- 
stand the  force  to  be  ai)plied  to  the  gold.  Hence  one  of  the  cements  is 
here  necessarv.  Previous  to  the  placement  of  the  cement,  should  the 
])ulp  be  near,  the  surface  should  be  covered  with  a  thin  solution  of  one 
of  the  resins  to  ])revent  the  influence  of  the  fluid  element  of  the  cement 
from  producing  irritation.  Copal  ether  varnish,  a  solution  of  hard 
Canada  balsam  in  chloroform,  or  the  solution  of  nitro-cellulose  in 
amvl  acetate  sold  as  "kristaline"  or  "  cavitine "  are  effective 
materials  for  thi>  jiurpose.  "When  the  cavity  is  deep  the  layer  of 
cement  should  be  brought  to  the  inner  line  of  the  retentive  grooves. 
As  soon  as  hardening  takes  place  the  metallic  covering  may  be  given. 

When  the  shallowness  of  the  cavity  will  not  ])erniit  a  considerable 
laver  of  the  cement,  a  metal  ca])  covering  the  ])ulp  wall  of  the  cavity 
tilled  with  the  cement  may  be  laid  in  place,  the  metal  of  the  cap  thus 
sustaining  the  force. 

These  forms  of  cavity  lining  are  of  great  utility,  and  should  be 
regarded  as  of  importance. 

Marginal  Cavity  Lining. — \\'hen  cavities  are  situated  on  approxi- 
mal  surfaces  of  the  teeth  and  extend  high  up  on  the  cervical  aspect  so 
as  to  place  them  beyond  the  probability  of  efficient  service  with  metal 
foils,  and  when  the  lateral  walls  of  cavities  are  weak  either  by  their 
thinness  or  by  instability  from  defects  of  structure,  some  form  of 
"lining"  is  necessary.  In  the  one  case,  to  ensure  certainty  of  per- 
formance at  the  cervix  ;  in   the   other,  to  prevent  injury. 

For  the  cervical  i)art  the  choice  is  between  (1)  tin,  (2)  a  combination 
of  tin  and  r/o/d,  and  (o)  (iinalgam. 

Tin  has  the  objection  when  superimposed  above  gold  tiiat  it  suffers 
waste,  in  most  instances  by  electrolysis,  to  which  the  mixture  of  tin  and 
gold  is  not  liable.  This  latter  combination — made  by  folding  a  layer 
of  the  tin  within  the  gold  foil — appears  to  give  the  tin  protection.  This 
combination  is  more  plastic  and  more  yielding  than  gold  alone,  and 
permits  adaptation   and   consolidation   in   places   difficult  of  approach. 


CAVITY  LINING  IN  RESPECT  TO  PROXIMITY  OF  THE  PULP.   219 

When  used  in  connection  with  a  matrix  thorough  consolidation  may 
be  effected  without  injury  to  tlie  cervical  margin  Avhen  the  tissues  are 
not  dense. 

When  the  color  of  a  lining  at  the  cervix  Avill  not  be  objectionable, 
a  quick-setting  amalgam  answers  extremely  well,  and  may  at  the  same 
sitting  be  followed  by  the  completion  of  the  operation  with  gold.  In  this 
situation,  whatever  the  lining  material,  close  conformity  w^ith  the  lines 
of  the  cervical  form  of  the  tooth  must  be  assured.  In  many  instances 
the  lining  and  the  completion  of  this  portion  of  the  filling  should  be 
effected  before  the  rubber  dam  is  placed,  when  the  lining  portion  is  for 
the  time  being  considered  in  its  relations  as  a  part  of  the  tooth. 

When  it  is  necessary  to  use  the  mineral  cements  on  approximal  sur- 
faces of  the  posterior  teeth  for  temporary  purposes,  the  cervical  border 
should  be  covered  with  a  line  of  gutta-percha  stopping,  to  protect  this 
^  vulnerable  part  of  such  fillings  from  the  exposure  of  this  border  by 
the  solution  to  which  they  are  there  liable. 

Lining-  Lateral  "Walls. — For  this  purpose  choice  should  be  made  of 
zinc  phosphate,  since  it  has  the  required  strength  and  enters  into  the 
necessary  adhesive  union  with  the  margins  to  give  the  required  secur- 
ity. The  layer  should  be  kept  within  the  extreme  outer  border  of  the 
cavity,  to  permit  the  metal  filling  to  overlay  the  margin  of  the  enamel. 
When  the  cavity  is  deep  the  retaining  groove  may  be  formed  in  the 
cement. 

A  general  summary  of  cavity  lining  is,  that  this  procedure  is  required 
in  proportion  to  the  difficulty  of  effective  approach,  and  for  the  safe 
treatment  of  teeth  below  the  average  of  structural  quality. 


CHAPTER   X. 

TREATMENT  OF  FILLINGS  WITH  RESPECT  TO  CONTOUR, 
AND  THE  RELATION  OF  CONTOUR  TO  PRESERVATION 
OF  THE  INTEGRITY  OF  APPROXIMAL  SURFACES. 

By  S.  H.  Guilford,  D.  D.  S.,  Ph.  D. 


The  treatment  of  a  cavity  of  decay  by  filling  must  have  a  tAVofold 
object  in  order  to  subserve  its  best  purposes  :  first,  the .  restoration  of 
the  affected  part  to  a  healthy  condition  ;  and  second,  the  prevention  as 
far  as  possible  of  a  recurrence  of  the  lesion. 

The  first  is  accomplished  by  the  removal  of  all  disintegrated  tissue 
and  the  perfect  filling  of  the  cavity  with  a  suitable  and  durable  material. 
The  second  demands  for  its  success  a  proper  understanding  of  the  cha- 
racter of  the  surfaces  operated  upon  and  their  mechanical,  physio- 
logical, and  pathological  relations.  While  the  simple  filling  of  a  cavity, 
if  properly  done,  will  generally  prevent  the  extension  of  decay  on  ex- 
posed surfaces,  the  same  operation  on  surfaces  less  favorably  situated  may 
utterly  fail  to  subserve  the  desired  end. 

The  contiguity  of  the  approximal  surfaces  of  teeth  greatly  favors 
the  retention  of  food  and  the  harboring  of  micro-organisms,  while  at 
the  same  time  it  prevents  the  free  cleansing  movement  of  saliva  be- 
tween them.  For  these  reasons  such  surfaces,  though  originally  per- 
fect in  their  continuity,  are  attacked  by  caries  more  frequently  than  any 
others,  except  the  occlusal  surfaces  where  continuity  is  broken  by  fis- 
sures and  pits.  When  once  affected  by  caries,  their  restoration  by  fill- 
ing is  difficult  owing  to  their  inaccessibility,  and  while  the  operations 
on  this  account  often  lack  the  perfection  that  would  otherwise  be  secured 
and  the  fillings  consequently  fail,  the  recurrence  of  decay  is  due  to  the 
persistence  of  the  same  influences  that  brought  about  the  initial  lesion. 

This  being  the  case  it  is  obvious  that  the  original  conditions  must  be 
changed  if  immunity  from  future  decay  is  to  be  expected.  This  principle 
was  early  recognized,  and  the  first  attempt  to  alter  the  conditions  was 
by  filing  or  cutting  the  approximal  surfaces  so  as  to  free  them  from  con- 
tact, on  the  principle  of  "  no  contact,  no  decay."  Where  all  of  the  teeth 
were  thus  separated  decay  was  temporarily  checked,  although  at  the  cost 
of  great  loss  of  masticating  surface,  much  disfigurement,  and  subsequent 
serious  injury  to  the  gum  and  pericementum. 

221 


222  THE  SELF-CLEANSL\G  SPACE. 

WhvYv  only  :m  occasional  ^pacc  of  this  character  was  niado,  the 
o})eration  proved  a  failure  because  in  a  short  time,  through  the  pressure 
of  adjoinint;-  teeth  and  altered  occlusion,  the  mutilated  teeth  would  a^in 
l)e  hrouoht  into  contact  and  the  opportunity  for  decay  be  increased  a 
hundredfold.  With  the  recurrence  of  decay,  cutting  or  filing  would 
again  have  to  be  resorted  to  until  but  little  of  the  teeth  remained,  and 
they  M'ere  eventually  lost.  On  account  of  its  unfortunate  results  the 
method  was  for  a  time  abandoned,  but  in  1870  it  was  revived  in  a 
modified  form  through  the  teachings  and  writings  of  Dr.  Robert 
Arthur.  His  method  consisted  in  altering  the  form  of  the  approximal 
surfaces  of  teeth  by  filing  or  grinding  so  as  to  change  the  point  of  ap- 
proximal contact  from  near  the  occlusal  surface  to  near  the  cervical 
margin.  This  not  only  changed  the  normally  convex  a])proximal  sur- 
face into  a  fiat  or  plane  one,  but  was  also  supposed  to  free  it  from  further 
liability  to  decay  by  preventing  the  retention  of  food  d6bris  and  render- 
ing the  surfaces  and  spaces  "  self-cleansing."  The  method  was  measur- 
ably adopted  by  numbers  of  conscientious  practitioners  as  a  means  of 
obviating:  a  difficultv  hitherto  unsuccessfullv  combated.  In  a  short 
time,  however,  it  was  discovered  that  its  promise  of  success  was  not 
being  realized,  and  it  was  also  gradually  abandoned.  Its  failure  was 
due  to  its  being  wrong  in  principle,  for,  while  it  seemed  to  offer  tem- 
porary relief,  its  after  results  were  most  disastrous. 

Bv  leaving  a  shoulder  near  the  cervical  margin  the  point  of  contact 
was  simply  transferred  from  one  point  to  another  with  the  result  that 
the  latter  point  was  far  more  liable  to  caries  than  the  former  one,  owing 
to  its  position.  ^Fcn-e  than  this,  the  exposed  dentin  on  the  cut  surfaces, 
lacking  the  natural  j)roteetion  of  the  enamel  covering,  was  apt  to  be 
sensitive,  and  the  food  crowding  into  the  space  and  pressing  upon  the 
gum  rendered  it  hyj)ersensitive  and  eventually  caused  its  recession. 
The  discomfort  following  this  operation,  together  with  the  increased  lia- 
bility to  decay  resulting  from  it,  were  sufficient  to  condemn  the  method 
and  cause  its  abandonment. 

These  failures  to  secure  freedom  from  decay  by  an  unnatural  altera- 
tion of  the  natural  forms  of  approximal  surfaces  led  to  a  more  carefnl 
investigation  of  the  causes  responsible  for  its  recurrence  on  these  surfaces, 
and  the  gradual  adoption  of  more  rational  and  scientific  methods  for  its 
prevention.  It  was  apparent  to  even  the  most  casual  student  of  compara- 
tive dental  anatomy  that  the  number  and  kinds  of  teeth  found  in  the 
jaws  of  man,  their  arrangement  in  the  arches,  and  their  general  form, 
were  all  such  as  to  best  subserve  the  wants  and  needs  of  the  individual, 
but  the  more  minute  points  of  their  external  anatomy,  their  interdepend- 
ence and  relation  to  one  another,  and  the  conditions  productive  of  caries 
had  not  previously  been  carefully  inquired  into.     Under  the  old   belief 


NORMAL   CONTOUR  IN  RELATION  TO   CARIES.  223 

that  contact  caused  decay  it  was  thought  that  decay  upon  approximal 
surfaces  always  began  at  the  point  of  contact  and  that  this  was  due  to 
fermentation  occurring  in  food  debris  retained  there.  Investigation 
proved,  however,  that  the  points  of  contact  between  teeth  were  not  only 
free  from  decay,  but  more  or  less  polished  from  slight  motion  of  the  teeth 
in  their  sockets,  and  that  approximal  decay  always  began  jugt  above  the 
contact  point,  that  is,  slightly  nearer  the  gum  margin. 

It  was  further  noted  that  the  normal  contact  of  teeth  on  their 
approximal  surfaces,  which  was  formerly  supposed  to  be  essential  only 
for  mutual  support,  was  equally  necessary  for  the  protection  of  the 
tender  gum  tissue  from  injurious  pressure  of  food  in  mastication. 

Finally  it  was  observed  that  those  portions  of  the  crown  of  a  tooth 
that  were  beneath  the  gum  margin  or  those  above  it  that  were  constantly 
covered  by  saliv^a  (as  on  the  approximal  surfaces  near  the  gum)  were 
always  free  from  the  beginnings  of  decay,  and  that  the  approximal  and 
buccal  or  lingual  surfaces,  when  faultless  in  structure,  were  first  attacked 
by  caries  on  a  line  corresponding  with  the  point  to  which  the  fluids  of 
the  mouth  usually  rose.  An  explanation  of  this  peculiarity  was  found 
in  the  fact  that  the  saliva  is  usually  alkaline  and  consequently  protective 
of  the  parts  covered  by  it,  but  at  its  surface,  in  a  state  of  rest  (as  in  sleep), 
this  condition  of  alkalinity  is  changed  to  one  of  acidity — the  calcium 
salts  are  dissolved  and  decay  is  begun. 

Furthermore,  the  micro-organisms  which  bring  about  fermentative 
changes  in  the  debris  of  carbohydrate  food  in  the  mouth  produce  lactic 
acid,  which  is  a  solvent  of  the  inorganic  constituents  of  tooth  substance. 
This  action  takes  place  more  readily  on  surfaces  not  normally  covered  by 
saliva,  and  in  the  protected  locations  not  subject  to  the  mechanically 
cleansing  action  of  the  tongue  and  buccal  walls. 

As  a  result  of  the  foregoing  observations  and  investigations  it 
became  apparent  to  the  mass  of  intelligent  workers  in  the  field  of 
operative  dentistry  :  1st.  That  the  natural  form  or  outline  of  each  tooth 
was  the  best  for  its  particular  function,  and  that  to  materially  alter  it  was 
to  lessen  its  usefulness  and  hasten  its  loss.  2d.  That  contact  of  ad- 
joining teeth  was  essential  both  to  the  comfort  of  the  individual  and 
the  durability  of  the  organs.  3d.  That  inasmuch  as  the  teeth  originally 
decay  in  spite  of  their  natural  form  and  contact,  some  plan  would  have 
to  be  devised  by  which,  in  their  repair  after  decay,  liability  to  a  recur- 
rence of  caries  would  be  greatly  lessened  if  not  entirely  prevented. 

To  fulfill  these  requirements  there  was  but  one  course  left  to  pursue, 
namely,  to  fill  approximal  cavities  in  such  a  way  as  to  restore  the 
original  contour  of  the  surface,  and,  in  all  cases  where  the  extent  of 
decay  was  sufficient  to  warrant  it,  to  extend  the  cavities  so  far  over  upon 
the  buccal  and  lingual  surfaces  as  to  bring  the  enamel  margins  within 
the  range  of  protective  influences. 


224  CAPILLARITY  OF  APPROXIMAL  SURFACES. 

The  rationale  of  original  antl  recurring  deeay  upon  approxiraal 
surfaces  is  readily  made  apparent  by  considering  certain  facts  and  prin- 
ciples of  physics. 

When  a  tube  is  inserted  in  a  liquid  capable  of  wetting  its  surface 
the  liquid  will  rise  to  a  higher  level  within  the  tube  than  the  surface 
level  of  the  surrounding  liquid.  The  force  which  produces  this  result 
is  known  as  capillary  attraction,  and  is  explained  upon  the  principle  of 
"  surface  tension  of  liquids."  If,  instead  of  a  tube,  two  rounded  or  flat 
plates  are  immersed  in  the  liquid,  the  same  rising  of  the  fluid  between 
them  will  be  noticed.  The  smaller  the  tube,  or  the  nearer  the  two  plates 
are  together,  the  higher  will  the  liquid  rise. 

Applying  the  principles  governing  these  facts  to  the  teeth  and  con- 
sidering them  as  bodies  immersed  in  a  liquid,  it  will  readily  be  seen  that 
if  the  approximal  surfaces  of  the  teeth  were  parallel  and  close  together 
the  fluids  of  the  mouth  would  rise  to  a  higher  level  between  them  and 
cover  more  tooth  surface  than  if  they  stood  farther  apart,  and  being 
retained  in  this  narrow  space  with  little  opportunity  for  motion  they 
would  assume  an  acid  character  and  destruction  of  the  tooth  tissue  begin. 
This  is  what  takes  place  upon  approximal  surfaces  made  flat  by  filing, 
and  will  occur  whether  fillings  have  been  placed  in  such  surfaces  or 
not. 

Normally,  however,  the  crowns  of  the  human  teeth  are  more  or  less 
convex  upon  their  approximal  surfaces  and  touch  each  other  only  at  the 
point  of  their  greatest  transverse  diameters,  which  is  near  to  and  just 
above  the  occlusal  surface.  From  this  point  their  diameters  gradually 
become  less  until  they  reach  the  cervical  border,  where  they  are  smallest. 
This  leaves  a  triangular  interdental  space  Avith  the  base  of  the  tri- 
angle at  the  gum,  as  shown  in  Fig.  176,  in  which  the  saliva  will  rise  but 
a  short  distance  owing  to  the  se])arati()n  near  the 
gum  and  the  consequent  lessening  of  the  capil- 
lary attraction.  For  this  reason  teeth  preserving 
their  normal  forms  are  less  liable  to  approximal 
decay   than   they   could   possibly  be    under   any 

Showing  normal  contact  of       otllCr  COuditioUS. 
teeth 

The  earliest  treatment  of  approximal  sur- 
faces with  a  view  to  the  prevention  of  caries  consists  in  gaining  access 
to  them  by  wedging,  and  if  found  to  be  superficially  aifected  by  caries 
the  removal  of  the  injured  structure  and  the  perfect  polishing  of  the 
surfaces. 

When  cavities  of  moderate  size  are  discovered  they  should  be  care- 
fully prepared  and  filled,  preserving  the  original  contour  as  far  as 
possible.  Decay  may  recur,  but  it  is  less  likely  to  do  so  with  advan- 
cing age,  increased  density  of  tissue,  and  proper  prophylactic  treatment. 


CONTOURING  AS  A   PROTECTIVE  MEASURE.  225 

Where  the  decay  is  of  larger  extent,  however,  we  have  it  in  our  power 
to  make  such  physical  change  in  the  parts  aifected  as  to  render  future 
immunity  from  decay  reasonably  certain. 

First,  it  is  necessary  to  separate  the  teeth  well  by  wedging,  to  so 
enlarge  the  cavities  as  to  bring  their  lateral  margins  well  out  upon  the 
lingual  and  buccal  surfaces,  and  to  extend  the  cervical  margins  of  the 
cavities  down  to  or  beneath  the  free  margin  of  the  gum. 

Next,  the  fillings  must  be  carefully  inserted,  built  out  to  fully 
restore  the  original  contour,  and  most  perfectly  finished.  When  this 
has  been  done  and  the  teeth  have  returned  to  their  former  positions 
the  approximal  surfaces  will  be  in  a  better  condition  to  resist  the  influ- 
ences of  decay  than  they  originally  were,  and  while  the  cervical  border 
of  the  filling  is  protected  by  being  constantly  covered  by  saliva  the 
lateral  borders  are  so  far  out  upon  their  respective  surfaces  as  to  be  sub- 
ject to  the  cleansing  influences  of  the  lips  and  tongue. 

In  addition  to  this,  and  scarcely  less  important,  the  restoration  of 
contact  on  the  approximal  surfaces  aflbrds  normal  protection  to  the 
tender  gingivae  by  preventing  the  lodgment  and  pressure  of  food  upon 
them. 

The  contour  method  of  filling,  based  as  it  is  upon  physiological, 
anatomical,  and  mechanical  principles,  has  become  the  accepted  method 
of  operating.  Experience  has  proved  it  to  be  the  only  rational  method 
of  treatment  of  approximal  surfaces,  for  by  it  we  secure  all  the  desir- 
able conditions  of  preservation  of  the  natural  outline  of  the  teeth, 
necessary  contact,  immunity  from  future  decay,  and  protection  of  the 
gum  margins.  Its  practice  involves  some  sacrifice  of  healthy  tooth 
structure  along  the  buccal  and  lingual  aspects,  as  well  as  greater  ex- 
penditure of  time  in  filling  and  finishing,  but  the  results  compensate 
for  both  of  these. 

To  properly  perform  the  operation  of  filling  and  restoration  of 
approximal  contour  requires  not  only  manipulative  skill  of  a  high 
order,  but  also  an  artistically  trained  eye  in  order  that  the  restoration 
may  in  all  respects  correspond  both  in  extent  and  form  to  the  original 
outline  of  the  tooth ;  both  of  these  requisites  will  be  acquired  through 
frequent  repetition.  In  certain  cases,  as  where  the  teeth  originally  were 
not  quite  in  contact,  the  contour  may  often  be  advantageously  exaggerated, 
sometimes  considerably,  in  order  to  close  the  space,  but  it  should  never 
be  less  than    normal  or  the  result  will  not  be  satisfactory. 

In  the  filling  of  an  approximal  surface  next  to  a  space,  as  where  a 
tooth  has  been  lost,  the  necessity  for  full  restoration  of  contour  does  not 
exist  and  is  not  absolutely  demanded,  although  a  more  artistic  result  will 
be  secured  by  its  performance  in  all  cases. 

15 


CHAPTER   XI. 

THE    OPERATION    OF    FILLING    CAVITIES  WITH  METALLIC 
FOILS   AND  THEIR  SEVERAL   MODIFICATIONS. 

By  Edwin  T.  Darby,  D.  D.  S.,  M.  D. 


In  the  selection  of  a  filling  material  the  operator  should  consider  the 
character  of  the  secretions  of  the  oral  cavity,  the  position  of  the  tooth 
to  be  filled,  the  extent  of  the  diseased  area,  the  physical  structure  of  the 
tooth,  and  the  strength  of  the  cavity  walls.  A  filling  material  must 
possess  certain  inherent  qualifications,  the  most  important  of  which  are 
adaptability,  indestructibility,  non-conductivity,  hardness,  absence  of 
shrinkage,  harmony  of  color,  and  ease  of  manipulation.  All  of  these 
are  not  to  be  realized  in  any  one  material,  and  yet  some  of  the  more 
important  are  to  be  found  in  a  single  metal  or  in  a  combination  of 
metals. 

Lead  possesses  the  quality  of  softness  and  is  easy  of  adaptation  but 
is  readily  oxidized  when  exposed  to  the  air  or  the  secretions  of  the 
mouth.  Likewise  tin  possesses  characteristics,  such  for  instance  as  duc- 
tility and  softness,  low  conducting  power,  and  the  ease  with  which  it 
may  be  manipulated,  which  place  it  in  the  front  rank  as  a  preservative 
of  carious  teeth,  but  it  is  inharmonious  in  color,  and  its  very  softness, 
which  is  so  desirable  in  manipulation,  is  an  obstacle  to  its  use  upon 
surfaces  where  there  is  much  attrition.  The  zino  phosphates,  which  are 
composed  of  zinc  oxid  and  phosphoric  acid  in  solution,  form  a  com- 
bination which  at  first  attracted  the  favorable  attention  of  the  dental 
surgeon  as  possible  substitutes  for  metallic  foil  fillings.  They  possess, 
owing  to  their  plasticity,  ease  of  manipulation,  harmony  of  color,  com- 
parative non-conductivity,  and  absence  of  shrinkage,  many  desirable 
qualities,  but  are  lacking  in  one  essential  qualification,  namely,  inde- 
structibility. 

Gold. 

Gold,  which  has  been  used  for  about  a  century,  has  fulfilled  in  a 
more  marked  degree  than  any  other  material  or  combination  of  materials 
the  requirements  sought  for  in  a  filling  for  carious  teeth.  It  has  one  or 
two  objectionable  features,  such  as  high  conductivity  of  heat  and  inhar- 
monious color. 

227 


228  Tin:  uPEiiATios  or  I'UJ.iSd  ca\ith:s. 

Too  imu'li  stress  cannot  he  laid  ujxtn  the  uncstioii  of"  its  pnrity  it' tli(> 
best  results  arc  to  he  ohtaincd  from  its  nsc.  NN'liilc  it  is  claimed  hy 
manufacturers  ot"  d-'iita!  Ljiild  i'oil  that  tiieir  products  ai'c  ahsohitelv  free 
from  alloy,  it  is  nevt'rtheli-ss  true  thai  hut  few  specimens  of  dental  foil 
show  a  fineness  ahove  !H)!>.  W  this  standard  wci'c  always  attained  the 
operator  would  have  little  cause  for  complaint.  So  small  a  |)ercentage 
of  alloy  as  1  in  lOOO  would  not  materially  affect  the  workinji;  (pialitics 
of  the  product,  but  when  this  is  increased  to  4  or  (j  parts  ])er  lOOU  it 
manifesto  itself  by  harshness  and  intractability  under  the  instrument. 

Great  care  should  be  exercised  in  the  })reparation  of  the  foil,  since 
so  much  depends  upon  its  purity  and  cleanliness.  For  a  detailed 
description  of  the  process  of  manufacture,  from  the  injjot  to  the  beaten 
and  annealed  foil,  the  reader  is  referred  to  an  article  by  a  practical  foil- 
maker.' 

In  former  times  the  dental  surgeon  was  restricted  to  one  form 
of  gold  for  filling.  This  was  foil  ranging  in  thickness  from  4  to  10 
grains  to  the  leaf,  but  as  the  requirements  of  the  operator  broadened 
the  art  of  manufacture  increased,  and  new  pre[)arations  were  oficred, 
until  to-day  the  most  fastidious  can  find  such  as  will  please  ids  fancy  : 
foils  ranging  in  weight  from  4  to  120  grains  to  the  leaf;  cylinders  of 
various  sizes  and  composed  of  non-cohesive  and  semi-cohesive  foil ;  cohe- 
sive blocks  prepared  for  use  ;  rolled  gold,  varying  in  thickness  from  No. 
30  to  120,  and  crystal  gold  possessing  great  cohesive  properties.  These 
are  the  more  important  forms  in  which  gold  is  offered  the  operator  at 
the  present  time. 

Before  entering  upon  a  description  of  the  classes  of  cases  where  each 
of  these  seems  best  adapted,  it  may  be  well  to  describe  somewhat  in 
detail  the  peculiar  qualities  which  each  form  of  gold  presents  when 
subjected  to  clinical  use. 

Soft  or  Non-cohesive  Foil. — Prior  to  1854,  when  l>r.  Robert 
Arthur  discovered  and  promulgated  the  desirability  of  cohesive  foil  in 
certain  cases,  the  operator  used  gold  which  possessed  very  low  cohesive 
properties.  Used  as  it  then  was,  in  the  form  of  large  rope,  tape,  or  as 
cylinders,  the  property  of  cohesion  would  have  been  a  serious  objection, 
since  there  would  be  constant  danger  of  the  mass  clogging  and  bridging 
in  the  cavity,  and  the  cause  of  many  unfilled  places  along  the  cavity 
walls. 

The  terms  soft  and  Jtdrd,  when  used  to  designate  the  kind  of  gold,  are 
misleading,  since  all  gold  foil  prepared  from  pure  gold  or  gold  that  is 
nearly  pure  possesses  great  softness  under  the  instrument.  The  distin- 
guishing characteristics  between  the  two  kinds  of  gold  are  the  inability 
to  make  a  certain  kind  of  foil  cohesive  when  exposed  to  a  reasonable 

'  American  System  of  Dentistry,  vol.  iii.  p.  839. 


GOLD.  229 

degree  of  heat,  and  the  ability  to  render  another  make  of  equal  purity- 
cohesive  by  the  application  of  a  similar  degree  of  heat.  It  has  been 
claimed  by  some  manufacturers  of  dental  gold  foils  that  they  are  able 
to  procure  from  the  same  ingot  samples  of  non-cohesive,  semi-cohesive, 
and  extra-cohesive  gold,  attaining  these  physical  properties  of  the  mate- 
rial without  alloying  with  other  metals.  This  has  led  to  the  belief 
that,  since  absolutely  pure  gold  possesses  inherent  cohesive  properties, 
some  metallic  salt  or  other  foreign  substance  has  been  deposited  upon 
the  surface  of  the  leaf  of  non-cohesive  foil  which  has  the  power  of  pre- 
venting the  union  of  the  surfaces  of  the  foil  when  contact  is  sought. 
It  has  been  surmised  that  a  thin  film  of  iron  has  been  deposited  upon 
the  surfaces  of  the  leaf  of  non-cohesive  foil,  for  the  reason  that  if  a 
leaf  of  such  foil  be  melted  into  a  globule,  it  presents  a  reddish  brown 
appearance,  which  is  not  true  of  the  leaf  of  cohesive  foil  when  melted 
as  above. 

Much  of  the  so-called  non-cohesive  foil  offered  for  sale  is  not, 
strictly  speaking,  of  this  variety,  as  the  application  of  moderate  heat 
will  render  it  quite  cohesive.  It  possesses  the  softness  peculiar  to  pure 
gold  foil,  but  it  should  not  be  classed  with  the  variety  which  does  not 
weld  with  other  particles  of  the  same  metal  except  when  subjected  to 
great  heat. 

It  has  been  claimed  by  some  that  non-cohesive  foil  has  no  place  in 
dental  practice — that  any  tooth  which  can  be  filled  with  gold  may  be 
filled  with  cohesive  foil.  This  statement  may  be  true  in  the  main,  but 
it  is  also  true  that  many  teeth  having  strong  cavity  walls  can  be  just  as 
well  filled  where  a  large  portion  of  the  filling  is  made  with  non-cohe- 
sive foil,  and  with  a  great  saving  of  time.  Adaptation,  not  hardness, 
constitutes  the  saving  quality  in  cavity  filling. 

As  most  non-cohesive  foil  is  prepared  in  the  form  of  sheets  and 
is  placed  in  books  containing  one-eighth  of  an  ounce,  the  operator  is 
compelled  to  prepare  it  in  some  form  suitable  for  introduction  to  the 
cavity.  The  size  and  shape  of  the  cavity  will  be  some  guide  as  to  the 
best  method  of  preparing  the  gold.  The  narrow  tape,  the  mat,  the 
tightly  rolled  cylinder,  and  the  roll  or  rope  are  the  forms  best  adapted 
for  the  use  of  non-cohesive  gold  foil. 

The  tape  is  best  made  by  taking  one-half  or  one-third  of  a  leaf  of 
No.  4  or  No.  5  foil,  laying  it  upon  a  table  napkin  of  medium  size  folded 
square  as  it  comes  from  the  laundry ;  the  napkin  is  then  taken  in  the 
palm  of  the  left  hand,  and  the  foil  spatula  is  placed  in  the  middle  of 
the  piece  of  foil ;  the  hand  is  then  closed  tightly,  thus  folding  the  nap- 
kin, likewise  the  foil,  upon  the  sides  of  the  spatula.  This  process  is 
repeated  until  the  tape  is  one-eighth  or  one-sixteenth  inch  in  width 
(Fig.  177). 


^30 


THE   OPERATION  OF  FILLING   CAVITIES. 


If  iiiatx  arc  rcHiuired,  the  foil  may  he  iokled  twice  or  three  times  aud 
then  fohled  h'lijrthwise  upon  itself  until  mats  of  any  thickness  are  pro- 
duced, as  shown  in  Fig.  178. 

*  AVhen  non-cohesive  cyHnderii  are  desired,  it  is  better  for  the  operator 
to  make  them  rather  than  depend  upon  the  ready-made  ones  as  prepared 
by  the  mamifacturer,  since  these  are  usually  loosely  rolled  and  more  or 
less  cohesive.     The  tape  is  quickly  made  into  the  cylinder  by  rolling  it 


Fig.  177. 


Fig.  178. 


Tai.o>  til'  j^'olcj  loil. 


gs 


Mats  of  gold  foil. 


upon  a  five-sided  broach  to  the  desired  size.  The  depth  of  the  cavity 
is  a  guide  to  the  widtli  •>!'  tlic  tape,  and  the  width  of  the  tape  determines 
the  length  of  the  cylinder.  These  should  be  somewhat  longer  than  the 
depth  of  the  cavity.  The  manner  of  introducing  and  condensing  will 
be  described  later  when  special  cases  are  under  consideration. 

The  roll,  or  "  ro})e  "  as  it  was  formerly  called,  is  made  in  the  ft>llowing 
■wav  :  A  leaf  or  half  leaf  or  a  third  of  a  leaf  of  Ibil  is  rolled  between  the 


goM  foil. 


thumb  and  finger  until  a  roll  of  UKjderate  density  is  obtained.  As  foil 
is  contaminated  by  contact  with  the  moisture  and  surface  impurities  of 
the  hands,  it  is  better  to  avoid  such  contact  as  much  as  possible.  This 
can  be  completely  attained  by  rolling  it  upon  the  little  device  shown  in 
Fig.  179.  Any  operator  can  make  one  of  these  by  taking  two  pieces  of 
thin  board,  such  for  instance  as  the  lid  of  a  cigar  box,  and  fastening 
to  the  two  pieces  with  glue  a  piece  of  white  kid  about  eight  inches  in 


GOLD.  231 

length,  and  in  width  equal  to  the  sheet  of  foil.  Two  little  drawer- 
knobs  of  ebony  should  be  inserted  into  the  centre  of  each  of  the  pieces 
of  board.  These  act  the  part  of  handles  for  holding  the  appliance. 
The  gold  is  then  placed  upon  the  kid  strip  between  the  two  pieces  of 
board,  and  by  bringing  the  two  surfaces  of  the  kid  in  contact  the  foil  is 
rolled  between  them.  The  undressed  surface  of  the  kid  should  be  the 
one  upon  which  the  gold  is  rolled.  Ropes  thus  made  may  be  cut  in 
lengths  to  suit  the  size  of  the  cavity  to  be  filled,  and,  as  gold  thus  pre- 
pared has  great  softness  and  ease  of  adaptation,  it  may  be  inserted  in 
quite  large  pieces  if  plenty  of  condensing  force  be  applied  to  it. 

Cohesive  Gold  Foil. — All  gold  which  has  been  refined  by  any  of 
the  ordinary  methods  and  is  in  a  pure  state  may  be  said  to  be  cohesive. 
Nor  is  absolute  freedom  from  alloy  an  absolute  necessity.  It  has  been 
shown  that  softness  is  dependent  upon  purity,  but  a  foil  may  contain 
quite  a  percentage  of  silver,  copper,  palladium,  or  zinc,  and  yet  its 
cohesion  may  not  be  impaired.  It  may  also  be  alloyed  or  combined 
with  platinum  and  not  lose  its  cohesive  properties.  It  is,  however, 
desirable  that  cohesive  gold  be  pure,  since  the  smallest  percentage  of 
alloy  destroys  its  softness. 

When  two  sheets  or  laminae  of  freshly  annealed  foil  are  brought  into 
contact  and  slight  pressure  is  applied,  they  form  a  permanent  union  and 
are  practically  inseparable.  It  is  this  property  in  gold  to  which  the 
term  cohesive  has  been  applied.  But  this  property  is  soon  lost  by  the 
occlusion  of  gases  or  impurities  of  any  kind  which  may  be  deposited 
upon  the  surface  of  the  gold.^ 

Experiments  have  demonstrated  the  fact  that  if  the  gold  be  sub- 
jected to  the  fumes  of  ammonia,  hydrogen,  hydrogen  carbid,  hydrogen 
phosphid,  or  sulfurous  acid  gas  its  cohesive  property  is  quickly  de- 
stroyed, but  this  property  may  be  restored  by  heat  except  in  the  case 
of  sulfur  or  phosphorus  fumes.  Hence  the  importance  of  excluding 
the  gold  as  much  as  possible  from  the  atmosphere,  especially  during  the 
winter  months  when  gases  arising  from  the  combustion  of  coal  are  most 
liable  to  be  present  in  the  operating  room. 

Dr.  Black  has  shown  that  animoniacal  gas  has  the  power  to  prevent 
the  deleterious  influence  of  other  gases,  and  recommends  that  the  foil 
be  subjected  to  the  influence  of  carbonate  of  ammonia  by  keeping  it  in 
a  drawer  with  a  bottle  of  that  salt. 

The  advantages  of  cohesive  foil  cannot  be  overestimated.  With  its 
introduction  in  1855  began  a  new  era  in  the  possibilities  of  saving  cari- 
ous teeth.  Operations  which  were  deemed  impossible  by  the  use  of 
non-cohesive  foil  were  made  comparatively  easy  by  the  intelligent  use 
of  cohesive  foil.     The  restoration  of  broken-down  or  badly  decayed 

^  G.  V.  Black,  Dental  Cosmos,  vol.  xvii.  p.  138. 


'>:V2 


Tin:   ol'KJlATloX    or  FUJJXa    ('AVITIKS. 


teeth  became  the  common  practice  in  the  hands  of  the  skilfnl,  and  niod- 
ern  methods  of  practice  coupU'd  with  intelligent  use  of  this  form  of 
vTiAiX  have  made  it  possible  for  the  operator  of  iiKxh  in  times  to  do  that 
which  the  earlier  practitioner  deemed  impossible. 

The  beginner,  iiowever,  must  not  lose  sight  of  the  fact  that  cohesive 
foil  cannot  be  worked  after  the  same  methods  as  non-cohesive  foil.  To 
use  cohesive  foil  in  the  form  of  mats  or  cylinders  or  in  tightly  rolled 
ropes  would  mean  inevitable  failure  in  adaj)tation.  The  very  property 
which  renders  it  valuable  in  the  restoration  of  broken-down  teeth  and  in 
surfacinir  is  the  one  which  would  condemn  it  if  used  carelesslv  in  the 
interior  of  inaccessible  cavities.  Non-cohesive  gold  may  be  introduced 
into  a  well-shaped  cavity  in  large  masses,  and  because  of  its  softness 
and  ease  of  adaptation  may  be  made  to  touch  all  points  of  the  cavity 
walls  if  persistent  pressure  be  applied.  On  the  contrary,  cohesive  foil 
should  be  introduced  in  small  pieces,  the  first  of  which  should  be  well 
anchored  in  a  retaining  pit  oY  groove  and  each  subsequent  piece  welded 
thereto. 

There  arc  several  modes  of  preparing  the  beaten  cohesive  gold  foil 
for  the  cavity,  and  good  results  are  obtained  by  either  of  the  following 
methods. 

A  loosely  rolled  rope  made  of  a  quarter  sheet  of  No.  4  or  5  foil 
may  be  cut  into   lengths  varying  from   one-eighth    to   one-quarter  of 

Fig.  ISO. 


e 


Ribbons  and  .-trips. 


cl 


an  inch,  and  after  annealing  carried  to  the  cavity  upon  the  point  «^f 
the  plugging  instrument.     Or  a  leaf  may  be  folded  with  a  spatida  four 


GOLD.  233 

times,  making  a  broad  ribbon,  which  may  be  cut  either  lengthwise  or 
crosswise  of  the  ribbon  in  pieces  one-sixteenth  or  one-eighth  of  an  inch 
in  width  (see  Fig.  180).  This  is  a  very  convenient  manner  of  working 
cohesive  gold.  Or  the  heavier  foil  up  to  No.  20  or  No.  30  in  thickness 
may  be  cut  in  strips  of  a  single  thickness  and  of  the  widths  above  indi- 
cated, and  after  annealing  may  be  packed  into  the  cavity — the  essential 
idea  being  ever  in  mind,  that  but  a  small  quantity  of  the  gold  shall  be 
under  the  instrument  at  a  given  time.  Cohesive  gold  which  has  been 
rolled  instead  of  beaten  to  the  desired  thickness  is  much  prized  by  some. 
It  has  been  asserted  that  greater  softness  is  obtained  when  gold  has  been 
thus  prepared.  Such  gold  should  not  be  more  than  No.  20  or  No.  30 
in  thickness  to  insure  the  best  results.  '  It  should  be  cut  into  narrow 
strips  and  after  annealing  be  folded  back  and  forth  as  rapidly  only  as 
each  previous  fold  has  been  well  condensed.  Good  results  are  only 
attainable  if  each  lamina  be  thoroughly  welded. 

The  loosely  rolled  cylinders  and  blocks  which  are  prepared  by  some 
dealers  and  offered  as  cohesive  gold  are  usually  but  slightly  cohesive, 
and  if  used  in  this  form,  without  re-annealing,  may  be  packed  in  the 
interior  of  cavities  without  danger  of  clogging,  but  if  freshly  annealed 
they  are  contraindicated,  since  there  is  more  or  less  danger  of  imper- 
fect union  of  all  particles  of  the  gold.  It  is  questionable  whether  the 
larger  sizes  are  admissible  when  the  filling  extends  beyond  the  cavity 
walls  and  great  solidity  is  an  essential  factor. 

Crystal  Gold. — This  form  of  gold  was  introduced  by  Mr.  A.  J. 
Watts  in  1853,  and  as  prepared  at  the  present  time  is  one  of  the  best 
preparations  of  cohesive  gold.  When  first  brought  out  the  method  of 
manufacture  was  faulty,  since  it  was  difficult  or  impossible  to  rid  the 
spongy  mass  of  nitric  acid  which  was  used  in  its  preparation,  but  since 
Mr,  Watts  adopted  electrolysis  instead  of  chemical  precipitation  the 
objectionable  features  no  longer  exist.  Gold  thus  prepared  manifests 
great  cohesive  properties,  and  when  used  with  care  as  beautiful  opera- 
tions can  be  made  with  this  gold  as  with  any  form  of  cohesive  foil.  The 
operator  should  not  lose  sight  of  the  fact  that  the  gold  is  to  be  intro- 
duced into  the  cavity  in  small  quantities.  Should  failure  attend  its 
use,  it  would  doubtless  be  from  the  attempt  to  introduce  it  too  rapidly. 
Gold  of  this  variety  comes  in  bricks  containing  one-eighth  of  an  ounce 
each,  and  is  either  torn  apart  in  irregular-shaped  pieces  or  cut  by  means 
of  a  razor  into  small  cubes.  This  gold  should  be  excluded  as  much  as 
possible  from  the  atmosphere  and  when  used  should  be  well  annealed, 
although  when  recently  made  it  is  quite  cohesive.  There  is  no  prepara- 
tion of  gold  better  adapted  for  starting  fillings  in  shallow  or  irregular 
cavities,  or  for  surfacing  fillings.  Many  operators  make  use  of  it 
always  for  starting  and  for  finishing  fillings. 


234  THE  OPEJiATloS   OF  FILLING   CAVrVIES. 

Crystal  Mat  Gold. — Tliis  is  nnolhcr  form  of  crystal  gold,  and 
differs  from  that  ])i-cviously  dcscrihcd  in  that  it  presents  a  more  compact 
form,  the  crystals  appearing  smaHcr  and  matted  together.  It  breaks 
and  crundjles  under  tlie  instrument  to  a  greater  degree  than  the  other, 
and  possesses  no  desirable  ([ualities  which  the  oth<r  has  not.  If  it  has 
anv  merit  it  is  for  finishing  the  fillings  npon  occlusal  surfaces,  or  sucli 
snrfaces  as  are  easy  of  access,  or  it  may  be  used  in  conjunction  with 
amalgam. 

Gold  and  Platinum. — This  form  of  gold  has  found  mnch  favor 
with  many  practitioners  for  the  restoration  of  incisal  edges,  or  where 
for  any  reason  great  hardness  of  surface  is  desired. 

An  ingot  or  bar  of  pure  gold  and  one  of  platinum  are  "sweated" 
together  and  then  rolled  to  the  desired  thinness,  usually  about  that  of 
No.  20  or  No.  30  foil.  It  is  then  cut  into  narrow  strips,  freshly  an- 
nealed and  used  after  the  same  manner  as  heavy  foil.  The  commingling 
of  the  platinum  with  the  gold  gives  the  filling  a  tint  more  nearly  the 
shade  of  the  tooth,  and  for  this  reason  it  is  much  used  upon  labial  sur- 
faces and  in  mouths  where  the  teeth  are  much  exposed. 

Gold  thus  conil)ined  with  platinum  is  much  more  rigid  than  gold 
alone,and  is  contraindicatetl  for  making  the  bulk  of  most  fillings.  The 
best  results  are  obtained  from  it  when  the  mallet  is  used  for  its  con- 
densation throughout. 

Annealing  Gold. 

After  the  manufacturer  has  reduced  the  gold  to  the  desired  thinness 
by  beating,  his  last  act  before  booking  it  is  to  heat  it ;  this  is  termed 
annealing.  The  object  of  this  is  to  remove  any  harshness  which  has 
been  given  to  it  by  the  process  of  beating.  All  metals  become  more  or 
less  stiff  or  rigid  by  hammering,  but  become  soft  again  by  the  applica- 
tion of  considerable  heat.  Gold  foil  which  has  been  recently  made  and 
excluded  from  the  atmosphere  or  certain  gases,  as  previously  men- 
tioned, may  present  sufficient  cohesive  properties  to  weld  satisfactorily, 
but  this  property  is  soon  lost,  and  reheating  becomes  necessary  if  it  is 
desirable  to  get  union  of  the  various  layers. 

Most  operators  make  use  of  an  alcohol  flame  for  annealing  gold  ; 
others  a  small  Bunsen  gas  burner.  Some  hold  the  piece  of  gold  to  be 
annealed  in  the  direct  flame  or  a  little  al)0ve  it ;  others  place  the  gold 
upon  a  tray  of  Ilu.ssia  iron,  mica,  or  platinum  and  hold  this  in  the  flame 
of  the  lamp  or  gas  jet.  This  latter  method  is  safest,  since  there  are  apt 
to  be  impurities  in  the  flame  dependent  upon  a  charred  wick,  a  particle 
of  phosphorus  dropping  into  the  wick  from  the  burning  match,  or,  in 
the  case  of  the  gas  jet,  imperfect  combustion  which  might  give  either 


INTRODUCTION  OF  THE  GOLD.  235 

carbon  or  sulfur  deposits  upon  the  surface  of  the  gold.     All  or  any 
of  these  accidents  would  impair  the  working  qualities  of  the  gold. 

The  most  satisfactory  method  of  annealing  gold  is  by  the  use  of  the 
Electric  Annealing  Tray.  Such  a  device  has  been  invented  by  Dr.  L. 
E.  Custer,  and  is  shown  in  Fig.  181.     By  this  method  the  gold  can  be 

Fig.  181. 


Custer's  electric  annealing  tray. 

heated  to  any  desired  degree  and  with  a  uniformity  not  easily  attained 
by  the  methods  generally  used.  The  working  qualities  of  foil  whether 
non-cohesive  or  cohesive  are  greatly  enhanced  by  the  application  of 
heat  at  the  time  of  using.  Gold  that  is  absolutely  non-cohesive  is  made 
tougher  by  annealing  and  yet  its  softness  is  not  impaired,  while  cohesive 
gold  may  be  made  either  slightly  or  decidedly  cohesive  according  as 
much  or  little  heat  may  be  applied  to  it.  It  is  the  practice  of  many 
operators  to  use  the  gold  but  slightly  cohesive  when  filling  cavities  sur- 
rounded by  strong  walls,  and  the  gold  known  as  semi-cohesive,  in  the 
form  of  loosely  rolled  cylinders,  is  much  used.  As  the  filling  approaches 
completion  the  cylinders  are  heated  and  additional  cohesive  property 
imparted  to  them.  But  when  the  object  is  the  restoration  of  contour  or 
building  up  of  teeth  which  have  been  broken,  the  gold  should  be  heated 
but  little  short  of  redness  in  order  that  the  greatest  cohesive  property 
may  be  realized. 

Introduction  of  the   Gold,  and  Manner  of  Adapting  It  to 
THE  Walls  of  the  Cavity. 

It  has  been  shown  in  Chapter  VII.  that  few  cavities  are  of  proper 
shape  for  retaining  the  filling  when  the  decay  alone  has  been  removed. 
Most  cavities  require  to  be  given  a  retentive  shape  so  that  the  filling 
shall  not  be  dislodged  during  its  introduction  or  by  mastication  or 
otherwise  after  its  completion.  In  former  times,  when  the  operator  was 
restricted  to  one  form  of  gold  and  that  the  non-cohesive  variety,  he  was 
compelled  to  prepare  his  cavities  accordingly ;  but  at  the  present  time, 
when  the  variety  is  almost  endless,  he  can  shape  his  cavity  with  a  view 


'2M't  rilE  OPERATIOS   nF  I'llJJSd    (AVITIKS. 

to  conserviiii;  tooth  stnictiirc,  mikI  w  licii  lie  lias  trivt'ii  it  a  sliain'  to  please 
liiiii  he  can  si'lcct,  from  tlic  iiiaiiy,  a  special  tonii  of  uold  that  will  meet 
his  rc(|uiri'in('nts. 

There  are  certain  i)rinci|»les  in\-ol\'e(l  in  the  |)acUin^  of  ^old  ^\•llich 
must  be  borne  in  mind,  and  the  operator  shonld  stndy  these  before 
introducing  his  tillinj::.  The  first  of  these  is  /'o/rr,  and  the  direction  and 
relation  of  that  force  to  tiie  object  to  be  attained.  If  a  ^iven  cavity  is 
to  be  filled  Avith  non-cohesive  gold  the  oj)erator  must  take  into  consid- 
eration the  strength  of  the  cavity  walls,  and  must  determine  whether  by 
the  wedging  process  which  he  will  exercise  in  the  effort  to  adapt  the 
gold  to  the  walls  of  the  cavity  he  will  run  the  risk  of  breaking  them. 

Non-cohesive  gold  is  usually  introduced  by  what  is  known  as  hand 
pressure.  Each  layer  of  gold  is  carried  to  the  floor  and  the  walls  of 
the  cavitv  by  a  process  of  wedging,  and  the  mechanical  arrangenu'ut  of 
each  piece  of  gold  should  be  such  that  no  portion  of  the  gold  can  es- 
cape when  the  filling  is  com]>leted.  It  will  be  shown  later  on,  when 
considering  the  various  types  of  cavities  to  l)e  filled,  that  in  small  cav- 
ities of  simple  shape  the  gold  ])rcpared  in  the  form  of  tape  is  best 
suited,  whereas  in  compound  cavities  or  those  of  greater  size  the  gold 
may  be  introduced  in  the  form  of  comjxict  cylinders  or  blocks. 

When  it  is  desirable  to  use  a  combination  of  non-cohesive  and  cohe- 
sive gold,  the  former  is  generally  introduced  first  and  the  cohesive  is  in- 
corporated with  it  by  driving  or  forcing  layers  of  cohesive  into  the  non- 
cohesive.  This  is  best  effected  by  using  single  layers  of  heavy  foil  or 
rolled  gold  of  a  thickness  equal  to  20,  30,  or  40  grains  to  the  leaf.  If 
the  filling  is  to  be  made  of  but  one  kind  of  gold  and  that  the  cohesive 
varictv,  both  hand  pressure  and  percussion  l)y  means  of  the  mallet 
may  advantageously  be  employed.  The  operator  who  has  learned  to 
combine  the  two  forms  of  gold  and  is  not  restricted  to  eitiun"  method 
of  packing  is  best  qualified  for  the  requirements  which  are  presented  in 
general  practice.  Perfect  adaptation  to  the  walls  may  be  effected  by 
either  method,  but  gn^ater  celerity  and  the  attainment  of  eqnal  excel- 
lence mav  be  reached  by  combining  the  two. 

Plugging  Instruments. —  In  the  selection  of  instrnments  fir  pack- 
ing gold  the  operator  should  have  a  sufficient  number  to  meet  his  every 
need.  Thev  should  be  of  such  a  variety  of  patterns  that  every  part  of 
every  cavity,  however  remote,  can  be  reached  with  ease.  It  is  a  mis- 
taken notion  that  a  large  number  of  instruments  (if  well  selected)  is 
confusing.  Tlie  operator  should  study  his  instrnments  and  know  their 
uses  as  thoroughly  as  he  knows  the  letters  of  the  alphabet,  and  if  this 
be  done  and  they  be  arranged  in  an  orderly  manner  in  his  case,  the  con- 
fusion will  be  manifest  in  their  ai)sence,  not  in  the  possessit)n  of  them. 

For  ])acking  non-cohesive  foil  none  are  better  adapted  than  the  set 
shown   in   Fig.  182,   made  from  patterns  furnished   by  Dr.  B.  J.  Bing. 


INTRODUCTION  OF  THE   GOLD. 

Fig.  182. 


237 


14  15  16  17 

Dr.  Bing's  set  of  pluggers. 

1  his  set  should  be  supplemented  by  a  small  and  a  medium 

ized  foot-shaped  condenser  (Fig.  183j,  for  packing      -p^^  jgg 

rliuders,  mats,  or  blocks  against  the  cervical  wall. 

The  handles  of  instruments   used   for  packing 

T  on-cohesive  foil  should  be  of  such  size  that  they 

can  be  grasped  firmly  in  the  hand.     When  made 

of  wood  they  are  light  in  weight  and  agreeable  to 

touch.     Plugging  instruments  should  have  as  few 

curves  and  angles  as  is  consistent  with  the  ability 

fto  reach  all  points  in  the  cavity.  As  these  are 
multiplied,  direct  force  is  sacrificed.  The  point  of 
the  instrument  should  be  as  nearly  as  possible  in  a 
line  with  the  shaft.  Deviations  from  this  rule  are  sometimes  necessary 
in  order  to  reach  all  points  in  the  cavity.  Most  plugging  instruments 
have  serrated  points  and  are  used  for  all  forms  of  gold.  As  a  rule  these 
serrations  should  be  shallow,  and  when  cohesive  gold  is  to  be  employed 
they  should  be  only  sufficient  to  prevent  slipping,  as  gold  that  is  quite 
cohesive  packs  as  readily  with  smooth  points  as  with  rough  ones. 

It  is  not  definitely  known  when  packing  gold  by  percussion  was  first 
suggested,  but  the  idea  is  quite  generally  accorded  to  Dr.  E.  Merrit  of 
Pittsburg,  who  as  early  as  1838   used  the  hand  mallet  for  condensing 


238 


THE   OPERATfON  OF  FILLING   CAVITIES. 

Vu:.  185. 

Fig.  ISO. 


Fig.  184 


Snow  and  Lewis  auto- 
matic mallet. 


The  Abbott  mallet. 


S.  S.  White  electric  mallet  "  Xo.  2.' 
Founded  on  the  "  Bonwill." 


INTRODUCTION   OF  THE  GOLD.  239 

the  surface  of  fillings  which  had  been  introduced  by  hand  pressure. 
The  first  mallets  used  were  of  light  weight  and  were  made  of  wood  or 
ivory.  As  the  method  became  more  general,  heavier  mallets  were  em- 
ployed, and  those  made  of  lead,  tin,  various  alloys,  and  steel  found  much 
favor.  Before  the  introduction  of  rubber  dam  for  excluding  moisture 
one  hand  of  the  operator  was  employed  in  holding  the  napkin,  and  it 
became  necessary  to  have  an  assistant  at  hand  to  do  the  malleting. 
This  led  ingenious  minds  to  discover  some  means  of  percussion  besides 
the  hand  mallet,  and  several  spring  instruments  known  as  automatic 
pluggers  were  introduced.  The  Snow  and  Lewis,  the  Foote,  and  the 
Salmon  found  greatest  favor,  and  all  of  them  were  good  of  their  kind. 
The  accompanying  cut  (Fig.  184)  shows  the  Snow  and  Lewis  Automatic 
Mallet  as  made  at  the  present  time.  When  pressure  is  applied  to  the 
point  of  the  instrument  a  spring  is  liberated  which  throws  a  plunger 
forward  with  great  force,  which  is  expended  upon  the  gold  beneath  the 
point.  The  impacting  quality  of  this  blow  is  not  excelled  by  any  of 
the  mechanical  devices  in  use.  It  is  so  constructed  that  a  light  or  a 
heavy  blow  can  be  given  at  will.  The  operator  will  do  well  to  adjust 
the  instrument  for  light  blows  when  using  it  in  close  proximity  to  frail 
or  delicate  walls,  as  there  is  more  or  less  danger  of  fracturing  them. 

Instruments  of  this  class  are  not  well  adapted  to  packing  gold  in 
the  posterior  teeth  of  the  lower  jaw,  as  the  blow  is  delivered  at  a  more 
or  less  acute  angle,  and  unless  care  be  exercised  when  the  operation  is 
nearing  completion  the  plugger  point  will  slip  from  the  surface  of  the 
filling  and  wound  the  soft  tissues. 

Another  instrument  of  this  type  devised  by  Dr.  Frank  Abbott  (see 
Fig.  185)  has  a  socket  at  either  end  of  the  hand-piece,  the  one  giving  a 
pushing  and  the  other  a  pulling  blow.  The  latter  is  serviceable  for 
condensing  gold  upon  distal  surfaces. 

The  ELECTRIC  MALLET  is  ouc  of  the  most  ingenious  devices  em- 
ployed in  dentistry.  The  first  practical  application  of  electro-magnetic 
force  for  dental  malleting  was  made  by  the  late  Dr.  W.  G.  A.  Bon  will. 
Its  latest  development  is  shown  in  Fig.  186.  This  instrument  has 
found  great  favor  among  dentists  for  packing  cohesive  gold .  Its  blows 
are  delivered  with  great  rapidity  and  with  such  force  that  great  solidity 
is  attainable.  A  pair  of  electro-magnets  transforms  the  electric  cur- 
rent into  electro-magnetic  force,  which  is  transmitted  to  the  hammer. 
The  electric  current  is  furnished  by  a  Bunsen  or  Partz  battery, 
or  the  controlled  current  from  a  dynamo  or  storage  battery  can 
be  used  as  the  motive  power.  The  direct  dynamo  current  of  110 
volts  can  be  so  modified  by  the  use  of  a  rheostat  that  its  use  may 
be  employed,  and  the  trouble  incident  to  keeping  a  battery  charged 
avoided.      In  the  hands  of  a  skilful  operator  there  could  be  nothing 


240 


THE  OPERATION  OF  FILLING   CAVITIES. 


better  tor  jnicking  cohesive 
gold.  The  best  results  are 
obtuiiietl  bv  its  use  wlien  tlie 
gold  is  prepared  iu  thin  lani- 
inte  or  where  a  single  thiek- 
ness  of  heavy  foil  or  rolled 
gold   is  employed. 

Considerable  experience  is  necessary  to 
enable  the  operator  to  use  this  instrument 
with  satisfaction  to  himself"  and  his  patient. 
If  the  plngger  point  be  pressed  hard  against 
the  filling,  the  blows,  which  are  delivered  with 
great  rapidity  and  force,  become  painful  and  dis- 
tressing and  there  is  also  danger  of  chipping  the 
cavity  walls.  The  better  plan  is  to  hold  the  point 
slightly  away  from  the  surface  of  the  filling  and 
allow  the  momentum  which  is  given  the  instru- 
ment by  the  falling  armature  to  complete  the 
union  of  the  various  pieces  of  gold. 

The  ENGINE  MALLET  (scc  Fig.  187)  is  intended 
for  use  upon  the  dental  engine.  It  is  made  with 
a  slip  joint  and  can  be  applied  in  place  of  the 
hand-piece  to  nearly  all  of  the  dental  engines  in 
use,  although  it  is  best  adapted  to  one  of  the 
"  cord "  engines  because  of  the  greater  freedom 
of  action.  The  instrument  siiown  in  the  illus- 
tration embodies  many  improvements  in  con- 
struction which  have  been  suggested  by  various 
operators  since  the  "  Bonwill  mechanical  mallet," 
on  which  it  is  based,  was  introduced,  and  a  point 
of  relative  perfection  has  been  reached  where  are 
combined  great  efficiency  with  compactness  and 
lightness  in  handling.  It  will  be  seen  by  the 
illustration  that  the  essential  feature  of  this  in- 
strument is  a  revolving  wheel  having  inserted  in 
its  periphery  a  hollow  cylindrical  steel  roller. 
This  constitutes  the  hammer.  It  gives  a  "  spring," 
not  a  "  dead  "  blow,  as  it  is  held  to  its  position  by 
a  stiff  steel  spring.  The  roller  revolves  slightly 
in  its  socket  at  each  contact  with  the  plunger. 
When  the  engine  is  run  at  ordinary  speed  the 
small  wheel  revolves  with  great  velocity,  deliver- 
ing upon  the  head  of  the  plunger  as  many  as  fif- 


INTRODUCTION   OF  THE  GOLD. 


241 


teen  blows  per  second.  The  force  of  the  blow  can  be  modified  at  will 
by  an  extremely  simple  contrivance,  as  follows  :  The  interdigitations 
seen  around  the  upper  end  of  the  sleeve  are  held  together  by  means  of 
a  spring  attached  to  the  sleeve.  Pulling  the  sleeve  away  from  the  head 
against  the  spring,  and  revolving  it  to  the  right  or  left,  raises  or  lowers 
the  head  of  the  plunger.  Upon  releasing  the  sleeve  the  spring  at  once 
throws  it  back  to  engage  with  the  head,  and  the  blow  is  heavier  or 
lighter,  according  to  the  direction  in  which  the  sleeve  has  been  revolved. 
The  impacting  power  of  the  blow  from  this  is  great,  and  in  the 
hands  of  an  experienced  operator  a  large  quantity  of  gold  can  be  con- 


GSS 


Fig.  188. 

£m^!2  fciiiMB  Cuiuis        EuimS  E":"::::ki!  * 


Webb's  set. 


ijilffflj" 


Chappell's  set. 

densed  in  a  short  space  of  time.  AVhen  cohesive  gold  foil  is  employed 
smooth  oval  points  may  be  used  with  most  satisfactory  results.  The 
point  should  not  be  pressed  hard  against  the  filling,  but  a  skimming  or 
smoothing  motion  given  to  the  instrument.  The  surface  of  the  filling 
when  thus  packed  has  a  polished  or  planished  appearance  as  if  done 
with  a  hand  burnisher.     Such  fillings  are  usually  of  great  density. 

There  are  other  mechanical  mallets  intended  for  use  on  the  engine 
which  have  what  is  known  as  a  "  cam "  movement.      They  are  not, 

16 


242  TlIK   OVKRATIOX   OF  I'lLlJyu    CAVITIKS. 

strictly  spoakin<r,  mallots,  for  the  instruniont  is  pushed  rather  than 
driven  forward  l)y  an  eeeentrie.  The  Iiii<'kiii<rhain  and  the  Holmes 
mallets  belong  to  this  class.  They  have  not  the  same  steadiness  of 
motion  as  the  ones  [)revi()usly  described,  and  for  this  reason,  among 
others,  have  not  been  in  general   use. 

In  the  selection  of  pfur/gcr  jtoiiif.s  for  power  mallets  the  operator  will 
do  well  to  confine  himself  to  those  having  more  than  one  row  of  serra- 
tions and  those  which  are  smooth-faced.  The  serrations,  if  any,  should 
be  extremely  shallow,  and  the  corners  of  the  instrument  slightly 
rounded.  Those  of  the  foot-shaped  variety  aiv  admirably  adapted  to 
power  mallets,  and  as  there  is  a  great  variety  of  })atterns  and  sizes  he 
will  have  little  difficulty  in  meeting  his  every  wish  in  this  })artieular. 
A  few  points  selected  from  the  Webb,  the  Varney,  and  the  Chajipell 
sets  will  fill  all  requirements.  The  accompanying  cut  (Fig.  188)  shows 
a  irood  workino;  set  which  has  been  selected  from  the  three  mentioned. 

Filling — by  Classes. 

(As  arranged  in  C'liai)ler  VIII.) 

I.    Simple  Cavities  on  Exposed  Surfaces. 
Bicuspids   and    Molars. 
Class  A. — The  small  cavities  uj)on  the  ocr/u.^al   snrfarrs   of  the 
bicnsjiids  and  molars  are  among  the  simplest  in  form.     They  are  shown 
in   Chapter  VII.,   Fig.    129.     Cavities  of  this  kind  are  (piickly  filled 
bv  means  of   non-cohesive  foil   in  the  form  of  tape  as  shown   in   Fig. 
177.     Such   cavities   are   usually  of  regular  shape  and  of  a  form  re- 
(juiring  little  if  any  additional  shaping   to  make   them  retentive.     A 
length  of  tape  varying  from   an  inch  to  two  inches  should  be  taken 
upon    a    wedge-shaped   plugger    point  and   carried  to  the    bottom   of 
the  cavity,  where  it  may  be  held  for  an  instant  with  a  point  in  the 
left  hand  ;  the  instrument  in  the  right  hand  makes  a  fold  of  the  gold 
and  carries  it  into  and  against  the  walls  of  the  cavity  by  a  lateral  mo- 
tion ;  fold  after  fold  is  then  carried  into  the  cavity  and  pressed  firmly 
in  every  direction.     As  it  is  always  best  to  finish  such  fill- 
ings  with    cohesive   gold,  a   strip   of  Xo.   20  cohesive  foil 
should  be  wedged  into  the  mass  already  in  the  cavity,  and 
then   all   subsequent  pieces  malleted,   to  give   the  occlusal 
surface  as  great  hardness  as  possible.     A  completed  filling 
Bicuspid  fis-     ^^  ^j^.^  ^|.^^^  -^  ^j^^^^.j^  j,j  pj      139      Perfect  adaiitation  to 

sure  cavit)-.  ^  ' 

the  walls  of  the  cavity  is  obtained  by  the  use  of  the  non- 
cohesive   fi)il,   and    great   solidity   is   oidy  essential   upon   the   surface. 
Cavities  of  tliis  <'liaracter,  though  of  greater  size,  are  found  in  the 
molars,  as  shown  in  Figs.  190-192,  and  may  be  filled  in  the  same  gen- 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES.  243 

eral  way.  Mats  of  foil  may  be  substituted  for  tape,  and  where  the  decay 
has  progressed  to  such  au  extent  as  to  involve  a  large  portion  of  the 
occlusal  surface,  making,  as  is  frequently  found,  large  round  and  quite 
deep  cavities,  the  gold  may  be  introduced  in  the  form  of  cylinders. 
In  former  times,  when  the  dentist's  only  means  of  excluding  moisture 

Fig.  190.  Fig.  191.  Fig.  192. 


Fillings  in  molar  tissure  cavities. 

was  the  napkin,  and  when  his  ability  to  keep  cavities  free  from  saliva 
was  for  a  limited  time  only,  the  use  of  cylinders  was  much  more  com- 
mon than  at  the  present  time  when  the  rubber  dam  is  generally  em- 
ployed. 

Cylinders  for  such  cavities  should  be  hand-made  and  of  No.  4  non- 
cohesive  foil  (Fig.  193).     They  should  be  long  enough  to  extend  above 

the  margins  of  the  cavitv  as  shown  in  Fig.  1 93  and  arranged 
Fig  193  .  ^  .  . 

around  its  walls.     The  first  one  is  usually  carried  to  that 

point  in  the  cavity  farthest  away,  and  should  be  pressed  with 

a  foot-shaped  instrument  against  the  wall.     Others  are  then 

put  in  place  and  wedged  laterally  until  room  is  made  in  the 

centre  of  the  mass  for  another  cylinder,  this  in  turn  being 

wedged  toward  the  outer  walls,  and  the  operation  continued 

occiusaTcav-  uutil  uo  more  cylinders  can  be  introduced.     The  cylinders 

ity  with  cyi-  ghould  then  be  condensed  with  2:reat  force  upon  their  pro- 

inders.  i  •  n        .  • 

trudmg  ends,  and  finished  with  cohesive  foil  in  the  same 
manner  as  previously  described.  This  mode  of  filling  is  best  suited  to 
deep  cavities  in  which  the  walls  are  nearly  parallel  and  yet  sufficiently 
strong  to  endure  great  lateral  pressure. 

In  a  cavity  of  unequal  depth,  where  the  central  portion  is  quite  deep 
and  the  sulci  radiating  from  it  quite  shallow  (see  Fig.  194),  it  is  well  to 
use  semi-cohesive  foil  in  the  central  portion  and  cohesive 
Fig.  194.        f^jj  j^  ^^  radiating  sulci.     Such  fillings  require  to  be  well 
anchored  at  the  extremities  of  the  fissures  lest  they  be  dis- 
lodged by  sticky  candy,  which  often  adheres  with  great 
Filled  stellate     tenacity  to  the  surface  of  the  gold.     The  operator  will  do 
cavity      in     well  in  filling  such  cavities  to  confine  himself  to  gold  that 
molar.     "^^      ^^  quite  cohesivc,  except  in  the  central  portion  as  above 
indicated. 
Class  B. — Cavities  situated  upon  the  buccal  surfaces  of  the  bicus- 
pids and  molars  are  rather  more  difficult  to  fill  because  of  the  difficulty 
in  getting  the  rubber  dam  beyond  the  cervical  border  of  the  cavity. 


244  THE  oPKRATioy  OF  i-iijjya  cAVirrKS. 

When  this  has  been  done  and  j»erteet  di yness  etl'ected  these  eavitics  may 
be  classed  as  simple  ones. 

In  small  or  non-elastic  months  it  is  often  dilticnlt  to  reach  the  second 
or  third  molars,  hence  the  view  of  the  cavity  is  somewhat  imj)aircd. 
In  selecting  the  gold  for  such  cavities  the  oj)erat<»r  must 
FiQ.  195.        ^,^j-p  Jjji^,^  consideration  the  depth  of  the  cavity.      If  it  be 
shallow  he  will  do  better  to  start  his  tilling  in  a  retaining 
pit  and  till  throughout  with  cohesive  foil.      If,  on  the  con- 
trary, the  cavity  be  of  considerable  depth,  he  may  till  the 
Buccal  cavity     bullv  of  the  cavitv  with  mats  or  tape  made  of  non-cohesive 
iniowersec-     ^^^jj   ^^^  ^^  j^^  approaches  the  surface  of  the  tilling,  incor- 

ond  molar.  '  7  i  I  &' 

porate  with  it  cohesive  gold  and  finish  his  operation  with 
the  last-named  variety.  Such  cavities  are  often  advantageously  filled 
throughout  with  Watts'  crystal  gold.  This  form  of  gold  is  easily  seated 
and  it  has  no  tendency  to  rock  or  move  in  the  cayity.  A  slight  under- 
cut along  the  upper  and  lower  border  of  the  cavity  is  sufficient  to  hold 
the  filling  in  place  (Fig.  195). 

When  these  cavities  assume  larger  proportions,  as  they  frequently  do 
in  the  lower  molars,  and  become  confluent  with  cavities  on  the  occlusal 
surface,  they  should  be  filled  after  the  fi)llowing  method  :  A  mat  or 
block  of  non-cohesive  fi)il  should  be  j)lace(l  at  the  border  nearest  the 
gum  ;  this  may  be  held  for  a  nionicnt  with  an  instrunicnt  in  the  left 
hand.  One  or  two  other  l)locks  may  be  laid  against  this,  and,  when 
they  have  been  well  fixed  in  the  undercut,  should  be  malleted  thoroughly 
against  the  cervical  border ;  the  remainder  of  the  cavity  may  then  be 
filled  with  semi-cohesive  or  cohesive  gold.  The  surfacing  of  all  fillings 
should  be  done  with  gold  which  has  been  made  cohesive  by  recent 
annealing. 

Class  C — Cav'ities  do  not  often  t)ccur  on  the  lingual  .surfaces  of  the 
bicuspids  or  molars  except  in  teeth  of  very  })oor  structure  and  in  teeth 
from  which  the  gum  has  receded  to  a  point  bek)W  the  enamel  border. 
Such  cavities  because  of  their  inaccessible  position  arc  difficult  to  fill 
with  gold,  and,  as  a  rule,  some  of  the  plastics  are  indicated.  When  the 
fissures  on  the  up])er  molars  become  the  seat  of  caries  they  may  be 
filled  with  gold  in  the  same  manner  as  those  in  class  />.  It  is  usually 
necessary  to  pack  the  gold  in  these  cases  almo.st  entirely  by  hand  pres- 
sure because  of  the  inaccessible  situation  of  the  cavity. 

Incisors  and   Canincx. 

Class  D. — Cavities  upon  the  labial  surfw-cs  of  the  incisors  and  ca)dnes 
situated  at  or  near  the  gingival  border  of  the  gum  were  formerly  the 
source  of  much  annoyance  to  the  dentist  when  gold  was  the  material 
selected  for  filling.     The  principal  difficulty  was  occasioned  by  mois- 


SIMPLE  CAVITIES  ON  EXPOSED  SVPFACES.  245 

ture,  either  iii  the  form  of  blood  or  serum  from  the  wounded  gum  or 
mucus  from  the   follicles  situated  along  the  mucous  surface.     Since  the 
introduction  of  the  rubber  dam  this  difficulty  has  been  greatly  modified. 
But  when  the  cavity  extends  somewhat  above  the  nor- 
mal gum  line  there  is  more  or  less  difficulty  in  keeping 
the  rubber  above  the  gingival  border  of  the  cavity.    This 
is  best  done  by  taking  a  straight  instrument  the  point 
of  which  has  been  made  very  sharp  by  rubbing  it  upon 
an  Arkansas  hone.     The  dam  is  then  raised  well  above 
the  cavity  border  and  the  point  pressed  firmly  into  the 
cementum  and  held  with  the  left  hand  throughout  tlic 

.  Till         Woodward  clamp. 

operation  oi  nlhng  the  cavity.     A  very  neat  and  valuable 
device  in  the  form  of  a  clamp  has  been  introduced  by  Dr.  W.  A.  Wood- 
ward for  this  purpose.     It  is  shown  in  Fig.  196. 

The  dam  should  include  not  only  the  tooth  to  be  filled,  but  several  on 
each  side  of  it.  With  the  left  hand  it  is  stretched  above  the  margin 
of  the  cavity,  while  with  the  right  hand  the  two  little  points  on  the 
bow  of  the  clamp  are  pressed  firmly  into  the  cementum  above  the  cavity. 
The  clamp  is  then  made  secure  by  turning  the  set-screw.  This  clamp 
when  well  seated  rarely  moves,  and  the  operator  feels  that  this  difficult 
operation  has  become  a  simple  one. 

There  are  cases,  however,  where  the  decay  has  followed  the  receding 
gum  or  extended  beneath  it  to  such  an  extent  that  the  clamp  cannot  be 
used.  To  overcome  this  difficulty  the  gum  should  be  slit  and  a 
"  Mack  "  screw  inserted  to  the  depth  of  two  or  three  threads  into  the 
dentin.  The  rubber  dam  is  then  drawn  above  this  and  held  securely 
above  the  cavity.  When  the  operation  is  completed  the  screw  should 
be  cut  off  with  the  wedge-cutters  and  nicely  smoothed.  When  the  slit 
in  the  gum  has  healed,  the  portion  of  the  screw  remaining  will  be 
concealed. 

Most  cavities  upon  the  labial  surfaces  are  shallow  and  are  best  filled 

with  cohesive  foil  or  Watts'  crystal  gold.    It  is  well  to  fix  the  first  piece 

securely  in  a  small  retaining  pit  and  build  each  piece 

Fig.  19 1.  upon  a  sure  foundation.     As  fillings  upon  the  labial 

Mj^J        surfaces  of  teeth  are  usually  conspicuous  (Fig.  197), 
F>Ti        it  is  often  desirable  to  fill  such  cavities  with  plat- 
t  ]|  II       inous   gold,  because  the  tint  of  the  two  metals  in 
Labial  fillings.  combination  is  more  nearly  the  shade  of  the  tooth. 

Especially  is  this  true  in  teeth  of  yellowish  hue. 

Class  E. — As  cavities  upon  the  lingual  surface  of  the  incisors  are 

usually  confined  to  the  laterals  and  most  frequently  are  the  result  of 

imperfect  development  of  the  enamel  in  relation  to  the  cingulum  (see 

Chapter  I.,  p.  25) ;  they  are  small  in  size  and  easily  filled.     A  tape  of 


24(3  THE   OPEllATloy   OF   I'll. LING    CAVITIES. 

non-fohc'sive  foil,  or  a  small  mat  o<"  tlic  same  material,  may  be  inserted 
into  the  cavity  first,  ami  the  filling  completed  with  cohesive  gold  as  in 
other  cavities  surrounded  by  strong  walls. 

Class  F. — As  caries  rarely  attacks  the  iiicisal  ecUjc  of  the  anterior 
tirf/i  the  operation  of  filling  with  gold  is  usually  confined  to  artificially 
made  cavities,  with  the  view  of  arresting  waste  (»f  tooth  substance 
caused  by  attrition,  or  where  for  any  reason  it  is  deemed  best  to  "  oj)en 
the  bite."  Great  strain  is  often  brought  to  bear  upon  fillings  in  this 
position,  and  too  great  care  cannot  be  exercised  in  the  shaping  of  the 
cavity  and  the  sul)se(juent  packing  of  the  gold. 

Cohesive  gold  is  best  suited  to  cavities  of  this  (jcscrijition,  and  each 

piece  shoidd   be  freshly  annealed,  that  thei-e  may  be  no  doubt  about  the 

perfect  union  of  each  piece.     It  is  well  to  start  the  first 

piece  in  a  small  retaining  or  stai'ting  pit  and  then  fill  all 

dof  the  undercut  before  attempting  to  build  the  gold  above 
the  walls.     As   fillings   in   this   position   are  subjected  to 
great  wear,   the   greatest   hardness   of  surface    attainable 
Edge  restora-     gj^Q^jj  ]jq  sought    for,  Otherwise    there  will   be  battering 
of  the  edges  and  possibly  fiaking  of  the  gold.     Platinous 
gold  is  well  adapted  for  this  kind  of  fillings.     Narrow  strips  of  Xo.  20 
or  No.  30,  well  annealed  and  condensed  with  mallet  force,  will  auswx^r 
a  better  purpose  than  lighter  foil  (Fig.  198). 

II.  Simple  Approximal  Cavities. 
Incisors  and   Canines. 

Class  G. — In  selecting  the  kind  of  gold  and  the  form  iu  which  it 
should  be  prepared  for  fillings  upon  the  approximal  surfaces  of  the 
incisors  and  canines,  the  operator  must  consider  the  size  of  the  cavity 
to  be  filled  and  the  retaining  hold  wdiich  he  is  able  to  secure  without 
sacrificing  too  much  of  the  tooth  structure. 

If  the  cavity  be  a  small  one,  situated  midway  between  the  labial  and 
lingual  walls,  and  the  surrounding  borders  be  strong,  a  rapid  and  easy 
way  of  filling  such  cavities  is  to  ])rcpare  the  non-cohesive  foil  in  the 
form  of  narrow  taj)e.  A  leaf  of  foil  cut  into  ibur  j)ieces  and  folded 
with  a  s])atula  U[)on  a  napkin  to  the  width  of  one-sixteenth  of  an  inch, 
and  then  cut  into  lengths  of  three-(|uarters  or  one  inch,  is  a  good  way 
of  preparing  it. 

An  excavator  of  an  angle  of  fijrty-five  degrees,  with  the  extreme 
point  broken  off,  makes  a  very  good  instrument  for  packing  such 
fillings.  Space  should  previously  be  obtained,  either  l)y  the  slow  pro- 
cess of  wedging  with  rubber  or  linen  tape  or  by  means  of  the  Perry 
separator. 


COMPOUND   CAVITIES.  247 

When  the  cavity  is  two-thirds  filled  it  is  well  to  use  a  few  pieces  of 
No.  20  cohesive  foil,  so  that  a  dense  surface  may  be  given  to  the  filling. 

Such  cavities  may  be  classed  among  the  simple  ones,  and  p^^  jgg^ 
present  no  difficulties  except  their  inaccessibility  (Fig.  199). 

The  operator  should  ever  strive  to  conceal  as  much  as  pos- 
sible the  gold  in  the  anterior  part  of  the  mouth,  and  when  it 
is  possible  he  should  preserve  the  labial  wall  intact.  This  can 
often  be  done  by  cutting  away  a  portion  of  the  lingual  wall 
and  by  packing  the  filling  almost  entirely  from  the  under  side  of 
the  tooth.  Where  a  large  portion  of  the  approximal  surface  is 
involved,  the  retaining  hold  for  the  filling  must  be  had  at  the 
cervical  border  and  at  the  incisal  edge.  The  first  pieces  of  gold 
should  be  anchored  in  a  groove  or  retaining  pit  near  the  cervix  and  the 
cervical  border  made  secure  before  any  other  portion  of  the  cavity  is  filled. 
The  beginner  will  ordinarily  do  better  to  start  such  fillings  with  cohesive 
foil  or  Watts'  crystal  gold.  If  the  latter,  he  may  then  complete  his 
filling  with  cohesive  foil.  Non-cohesive  gold  is  rarely  indicated  in  cav- 
ities of  this  description. 

The  electro-magnetic  mallet  or  the  Bonwill  mechanical  mallet  is  well 
adapted  for  packing  such  fillings. 

Bicuspids  and  Molars. 

Class  H. — Cavities  of  medium  size  situated  upon  the  mesial  or  dis- 
tal surfaces  of  the  bicuspids  and  molars  and  not  involving  the  occlusal 
Fig.  200.  surface  may  be  filled  after  the  same  manner  as  small  cav- 
ities in  the  incisors  or  canines.  Operators  who  are  not  in 
the  habit  of  using  non-cohesive  foil  prefer  starting  such  fill- 
ings in  a  small  undercut  or  retaining  pit  and  filling  through- 
out with  cohesive   p-old  prepared    either  in  narrow  ribbons 

Approximal  °  '^      ^ 

bicuspid       or  loosely  rolled  cylmders  (Fig.  200). 

^^^^°^'  Such  fillings,  because  of  their  position,  must  be  packed 

largely  by  hand  pressure,  although  the  mallet  may  be  used  as  the 
filling  approaches  completion. 

III.  Compound  Cavities. 

Incisors  and   Canines. 

Classes  I  and  ./. — Mesio-lahial  and  disto-labial  cavities  in  the  incisors 
and  canines  are  usually  best  filled  throughout  with  cohesive  gold.  Each 
cavity  independent  of  the  others  should  have  retentive  shape,  so  that  in 
the  event  of  one  filling  being  displaced  the  other  will  remain  intact. 

As  a  rule  it  is  better  to  fill  the  cavity  on  the  labial  surface  first, 
because  the  first  pieces  of  gold  are  more  easily  anchored  in  an  accessible 


^ 


248  riJE  oi'FlLWlny   OF  IlLLTNG   CUT7777X 

cavity,  :uul   hccaiisc  also   ot"   tlic  thiiiiicr  ol'   (li.-j»la*'iiin-   the   ^okl    in   tlie 

appniximal  cavity  wiicii  lillint;-  the  cliaiiiicl   connecting  the  two  fillings. 

Evcrv  i)(»ssil)lc  cai'c  siiould  he  exorcised  in  i)ackiii'r  the  trold 

in   cavities  of  this  description.     The  >jold    shonld    he   made 

/       \         thorontjhly  c(»hesive  hy  recent  annealing,  and  i)e  used  in  pieces 

^-I!2^j        snfHciently  small  to  prevent  clogging.     iSnch  operations  are 

.       fl        more   or  less  ex})()sed  to  view,  and  the  greatest  degree  of 

^•^        artistic  skill   shonld  be  bestowed  npon  them  to  render  them 

.Mcsio-laliiai  _  _  r  ^  '     • 

fiHiiiK.       as  pleasing  as  possible  to  the  eye.     The  original  outline  of 
the  tooth  shonld  be  restored  with  the  gold,  because  it  pre- 
sents a  better  appearance  than  a  space  between  it  and  the  adjoining 
tooth  (Fig.  201). 

Classes  ii' and  Jj. — Cavities  upon  the  nuK'to-liiKjaal  or  ilLsfo-lingual 
swfaces  of  the  teeth   are  filled   in    precisely    the   same   way  as  those 
described  under  classes  /  and  J.     It"  the  cavity  be  of  con- 
siderable depth,  non-eohesive  gold  may  be  used  as  part  of      ''i''  '-02. 
the  tilling,  but  in  any  event  the  bulk  of  the  filling  slioidd 
be  made  of  cohesive  foil  (Fig.  202). 

Classes  M  and  X. — Mesio-incisal ;  Dlsto-uwisal. — Cav- 
ities situated  upon  the  ai)proximal   surfiiccs  of  the  incisors     ,     . 

A  ^  /  _       _  ^  Ml'sio  -  lin- 

and  becoming  confluent  with  one  on  the  incisal  edge  require  guaiiiUiiiK. 
great  care  in  the  luatter  of  packing  gold.  It  is  often  an 
advantage  to  have  the  cavity  on  the  approxiraal  surface  unite  with 
a  natural  or  an  artificially  made  one  upon  the  incisal  edge,  because 
much  better  anchorage  can  be  obtained  in  such  cavities.  Cohesive 
gold  prepared  in  the  form  of  ribbon  or  in  pellets  or  cohesive  cylin- 
ders, if  loosely  rolled,  may  be  used.  The  better  method  is  to  fill 
the  undercut  at  the  cervical  border  of  the  cavity  first,  and  tlien  bring 
the  gold  toward  the  incisal  edge  as  squarely  as  possible,  keeping  the 
mass  on  a  line  with  the  labial  and  lingual  walls.  The 
operator  feels  a  sense  of  security  when  he  is  able  to  an- 
chor such  fillings  in  an  undercut  or  retaining  pit  on  the 
incisal  edge.  In  teeth  with  broad  incisal  edges  there  is 
ample  opportunity  to  make  a  strong  retaining  hold,  but 
where  the  edge  is  narrow  a  lateral  cut  into  the  palatal 
wall  one-third  back  from  the  incisal  edge  affords  a  strong 
and  secure  hold  for  that  portion  of  the  filling.  Operations  of  this  class 
require  great  thoroughness  in  the  packing  of  the  gold.  It  shoidd  be 
very  cohesive  and  when  possible  condensed  with  some  form  of  mallet 
(Fig.  203).  .*     .      .     . 

Class  0. — Mcsio-cUsto-incisdI. — AVhere  both  approximal  surfaces 
and  the  incisal  edge  arc  united  in  one  cavity^  the  better  plan  is  to  begin 
the  filling  at  the  undercut  near  the  cervical  border  of  the  distal  cavity, 


COMPOUND   CAYITIIES.  '  249 

and  build  the  gold  squarely  down  as  in  classes  M  and  N  until  the  in- 
pisal  edge  is  reached,  thence  across  the  incisal  edge,  then  fill  the  mesial 
cavity  after  the  same  manner,  uniting  the  three  fillings  at  the  mesio- 
incisal  corner.    It  is  better  to  insert  such  fillings  with  an 
electric  or  a  mechanical  mallet,  as  there  is  always  dan- 
ger, when  packing  across  the  incisal  edge  by  hand  pres- 
sure, of  pushing  one  or  the  other  of  the  fillings  out  of 
the  approximal  surfaces. 

If  no  accident  occurs  in  the  packing  of  the  gold  a     Mesio-disto-incisai 

.  .        .  fllliriKS. 

filling  thus  made  is  very  secure,  for  its  form  is  like  a 

staple  and  each  portion  helps  to  bind  the  others  securely  in  the  triple 

cavity.     Non-cohesive  gold  should  form  no  part  of  such  fillings  (Fig. 

204).' 

Bicuspids  and   Molai's. 

Class  P. — 3fesio-occlusal. — The  filling  of  this  class  of  cavities  offers 
no  serious  difficulties  provided  sufficient  space  has  previously  been  ob- 
tained. As  it  is  desirable  to  restore  with  gold  the  original  outline  of 
the  tooth,  sufficient  space  to  do  this  in  is  a  necessity,  and  the  operator 
will  soon  learn  that  he  can  only  accomplish  good  results  in  proportion 
as  he  recognizes  the  importance  of  this  preliminary. 

The  cervical  border  is  the  vulnerable  point  for  recurrence  of  decay, 
and  imperfection  here  in  the  matter  of  packing  the  gold  means  speedy 
failure  of  the  filling,  hence  the  importance  of  a  perfect  joint  between 
gold  and  tooth.  This  may  be  obtained  by  using  a  roll  or  rope  of  non- 
cohesive  foil.  One  end  of  the  roll  should  be  carried  with  a  suitable 
plugger  into  the  gingivo-linguo-axial  angle  of  the  cavity,  and  ex- 
tended across  the  gingival  border  into  the  gingivo-bucco-axial  angle. 
Gieat  care  should  be  exercised  at  this  point  in  reference  to  the  gin- 
gival border.  The  gold  should  be  first  thoroughly  matted  down 
with  a  broad-faced  plugger  and  then  a  few  blows  from  an  auto- 
matic or  hand  mallet  should  be  directed  upon  it  to  insure  perfect 
adaptation  to  this  wall  of  the  cavity.  Subsequent  rolls  of  non- 
cohesive  foil  may  be  introduced  in  the  same  manner  until  one-third 
or  even  one-half  of  the  approximal  cavity  has  been  filled,  after 
which  cohesive  gold  should  be  substituted  for  the  non-cohesive,  and 
its  use  continued  throughout  the  balance  of  the  filling.  Freshly  annealed 
gold  should  be  used  upon  the  surface,  that  a  compact  filling  may  be  the 
result. 

It  is  always  better  to  insert  too  much  rather  than  too  little  gold,  as 
the  operator  can  shape  the  contour  according  to  his  fancy  or  to  the 
necessities  of  the  case. 

The  occlusal  portion  of  the  filling  should  be  thoroughly  condensed^ 


2.jO  THS  opera  TIoX  OF  FILLISi;    CAVITIES. 

as  iiiiK'li  (-lepc'iuls  ujxtn  tliis  tor  holding  llic  lilliiig  in  jtlacc     (treat  hard- 
ness is  also  essential  to  prevent   hattcring  in  the 
Yii..  '_>or,.  .j^.j  ^^^.  ,„.,^ti^^..,tion  (Fig.  205). 

^^"\     ^^^\  C'r.Ass  (^. — 7>/Wo-o<'r/(/.s'a/ eavities  may  1)(' tilled 

flA^;  W^J  '•>  precisely  the  same  manner  as  those  situated 
^*^i— ^  ^-^  upon  the  mesio-oeelusal  surt'aee.  The  ditfieulties 
Approximo-occiusai        ^y^,  slightlv  greater  Ijecause  these  eavities  are  not 

cavities.  m  i  /-        •   •  /•     i  •       i  •      • 

so  accessible.  Cavities  of  this  description  can  be 
greatly  simplified  by  the  use  of  the  matrix.  This  little  device  converts 
compound  cavities  into  .simple  ones,  and  when  used  with  care  and  judg- 
ment facilitates  the  operation  of  filling  to  a  wonderful  degree. 

Experience  has  demonstrated  that  the  only  .-satisfactory  method  of 
filling  cavities  upon  the  approximal  surfaces  of  the  bicus])ids  and  molars 
is  to  restore,  by  means  of  filling  material,  the  original  outline  of  the 
tooth.  This  is  termed  "restoration  of  contour."  To  do  this  success- 
fully requires  artistic  sense  and  mechanical  skill  of  a  high  order,  and 
an  accurate  knowledge  of  the  topographical  anatomy  of  the  teeth.  To 
the  man  who  has  these  the  operation  is  easy,  but  otherwise  persistent 
effort  alone  will  enable  him  to  acquire  the  ability.  The  inexperienced 
operator  will  often  do  better  if  he  confine  himself"  in  the  beginning  to 
but  one  kind  of  gold,  and  that  of  the  cohesive  variety.  If  this  be  done 
he  should  start  the  filling  in  a  well-defined  groove  at  the  cervical  border 
of  the  cavity,  and  then  add,  piece  by  piece,  well-annealed  foil  until  the 
filling  is  completed.  Such  a  procedure  is  of  necessity  slow,  but  excel- 
lent operations  can  be  made  by  this  method.  The  beautiful  and  lasting 
o]ierations  of  Yarney  and  AVebb  and  others  were  made  in  this  way. 

The  matrix  is  best  suited  to  disto-occlusal  cavities.  It  is  sometimes 
employed  upon  me.sio-oeclusal  cavities,  but,  as  a  rule,  obstructs  the  light 
and  adds  little  to  the  convenience  of  the  operator.  The  subject  of  filling 
with  the  aid  of  the  matrix  is  treated  in  detail  in  Chapter  XII. 

Fig.  206.  Fig.  207.  Fig.  208. 


Occliiso-biKcal  filling.        Occluso-lingual  filling.  Mc.^io-octluso-distal  filling. 

Class  R. —  Occluso-buceal  cavities  are  usually  confined  to  the  lower 
molars.  If  they  be  shallow  it  is  better  to  fill  throughout  with  cohe- 
sive gold.  If,  on  the  other  hand,  the  cavity  upon  the  occlu.sal  surface 
be  deep,  non-cohesive  gold  may  be  used  in  })art  and  then  cohesive  gold 


FILLING    WITH  TIN.  251 

used  to  fill  the  channel  connecting  the  two  cavities.  Such  fillings  are 
subjected  to  great  wear  and  should  be  solid  (Fig.  206). 

Class  *S^. —  Occluso-Ungual. — These  cavities  are  nearly  always  con- 
fined to  the  first  and  second  upper  molars,  and,  as  a  rule,  are  best  filled, 
with  cohesive  gold.  The  channel  running  into  the  lingual  aspect  of 
the  tooth  is  not  often  deep,  and  non-cohesive  gold  is  contra-indicated 
(Fig.  207). 

Class  T. — Cavities  upon  the  mesial  and  distal  surfaces  of  the 
bicuspids  often  become  confluent  with  those  upon  the  occlusal  sur- 
face, and  it  becomes  necessary  to  fill  them  as  one  cavity.  Such  ope- 
rations are  simplified  by  the  use  of  a  matrix  upon  the  distal  surface. 
A  band  matrix  could  be  employed,  but  it  obstructs  the  light  somewhat 
and  the  operator  will  more  frequently  confine  himself  to  a  matrix  upon 
but  one  side  of  the  tooth.  The  filling  should  be  commenced  at  the 
disto-cervical  border,  and  after  inserting  a  few  mats  or  cylinders  of 
non-cohesive  foil  proceed  as  in  cavities  described  under  class  Q 
(Fig.  205). 

If  these  cavities  be  of  considerable  size  the  buccal  and  lingual  walls 
are  weakened  and  there  is  danger  of  their  being  broken  away  in  the  act 
of  mastication.  It  is  often  well  to  truncate  the  cusps  somewhat  and 
build  the  gold  well  across  the  occlusal  surface,  allowing  the  strain  to 
come  directly  upon  the  gold  instead  of  upon  the  tooth  structure. 

Pilling  with  Tin. 

It  is  not  definitely  known  when  tin  was  first  employed  for  filling 
carious  teeth,  but  it  has  been  used  for  at  least  a  century  and  has  found 
great  favor  with  many.  Prior  to  the  improvement  in  the  formulas  of 
dental  amalgams,  tin  was  used  more  generally  than  at  the  present  time. 

Tin  possesses  certain  inherent  characteristics  which  make  it  valuable 
as  a  filling  material.  Among  these  are  great  malleability,  non-conduc- 
tivity, and  it  is  thought  by  many  to  possess  antiseptic  properties.  But 
while  it  has  desirable  qualities  it  has  also  some  undesirable  ones,  such 
as  softness,  and  when  exposed  to  the  secretions  of  the  mouth  it  discolors, 
— which  facts  render  it  unfit  for  surfaces  exposed  to  great  wear  in  the 
act  of  mastication  and  upon  surfaces  exposed  to  view.  The  discolora- 
tion, however,  is  confined  to  the  surface,  and  teeth  filled  with  tin  are  not 
discolored  in  consequence  of  its  presence. 

There  are  various  inethods  of  preparing  tin  for  dental  purposes. 
That  which  has  found  greatest  favor  in  the  past  is  in  the  form  of  foil. 
The  tin  used  should  be  chemically  pure.  An  ingot  of  the  metal  is 
rolled  into  ribbon  and  then  beaten,  after  the  same  manner  a?  gold  foil, 
into  sheets  of  the  desired  thickness.  As  a  rule  it  is  not  beaten  as  thin 
as  the  former.     The  foil  best  suited  for  most  fillinp's  is  ISTo.  10. 


'2-i'2  TUK   ()I'FIi.\Tl<)\    OF   FlLLISa    C.W'ITIFS. 

I'lirc  till,  like  |>iirt'  i:<il(l,  is  (•(•licsivc,  aiul  lillings  of  jxrcal  solidity 
can  l)t'  made  if  the  operator  will  cxei^cise  care  in  packing  it.  The  best 
results  arc  obtained  by  taking  a  third  of  a  leaf  of  No.  10  foil  and  roll- 
ing it  into  a  loose  rope,  then  cutting  it  into  lengths  of  half  an  inch  or 
less  and  jnicking  each  piece  with  a  view  of  making  each  part  of  the 
filling  solid.  iSome  prefer  folding  the  sheet  with  a  sjxitula  after  the 
same  manner  as  gold  foil,  and  then  cutting  into  narrow  tape.  K<|ually 
good  results  are  obtainable  by  either  method. 

A  more  rapid  Init  less  .satisfactory  manner  of  introducing  the  fillings 
is  to  use  the  tin  in  the  form  of  cylinders,  not  relying  so  nuich  upon  the 
cohesive  properties  of  the  metal.  The  directions  for  using  gold  in  the 
form  of  cylinders  will  apply  equally  well  for  inserting  tin  foil. 

Shaving-s  of  Tin. — The  cohesive  property  of  tin  is  best  illustrated 
when  it  is  used  in  the  form  of  freshly  cut  shavings  from  a  revolving 
ingot  of  the  metal.  Any  operator  can  prepare  his  own  shavings  and 
have  them  fresh  daily  or  hourly,  if  necessary,  after  the  following 
method  :  Take  an  ordinary  corundum  Avheel  two  inches  in  diameter 
and  one-half  inch  in  thickness,  such  as  is  used  in  the  laboratory.  Make 
a  mould  of  this  in  .sand  or  marble  dust,  then  melt  in  a  crucible  or  ladle 
enough  pmr  tin  to  fill  the  mould.  AVhen  it  has  cooled  mount  aceuratelv 
upon  the  mandrel  of  the  laboratory  lathe,  and  from  it,  with  a  sharp  car- 
penter's chisel,  turn  shavings  of  great  tenuity.  AMien  freshly  cut,  and 
before  oxidation  of  the  surface  has  taken  place  by  exposure  to  the  atmo- 
sphere, it  will  be  found  that  the  tin  coheres  with  the  same  readiness  that 
pure  gold  does.  Broken-down  teeth  can  be  built  up  by  this  method,  or 
by  means  of  it  surfaces  may  be  contoured  as  with  gold. 

The  plugging  in.struments  best  adapted  for  tin  filling  are  those  hav- 
ing shallow  but  well-defined  serrations  and  points  not  too  broad.  As 
the  margins  are  approached  broader  points  and  condensers  mav  be  used, 
and  the  surface  should  be  well  burnished.  The  f)perator  must  not  lo.se 
sight  of  the  fact  that  while  tin  possesses  many  desirable  qualities  and  is 
easily  manipulated,  it  lacks  hardness  and  is  not  adapted  to  surfaces  where 
great  attrition  occurs.  Its  chief  value  is  found  in  its  use  upon  surfaces 
concealed  from  view  and  shielded  from  wear,  and  in  the  temporary 
teeth,  where  its  greatest  value  is  manifest. 

Tin  fillings  should  be  finished  with  the  same  care  as  gold  ones,  and 
the  same  directions  will  apply  in  all  particulars. 


FINISHING  FILLINGS. 


253 


Finishing  Fillings. 

Much  of  the  beauty  and  utility  of  a  filling  is  imparted  to  it  in  the 
finishing.  It  is  not  enough  that  it  be  well  made,  it  must  also  be  well 
finished  if  the  'best  results  are  to  be  attained. 

All  fillings  should  contain  rather  more  gold  than  it  is  intended  shall 
remain,  and  this  for  the  purpose  of  dressing  down  to  such  lines  as  will 
be  artistic  and  practical. 

Fillings  that  are  not  well  condensed  cannot  be  given  a  fine  finish. 
Solidity  of  the  surface  is  an  essential  quality.  After  the  last  piece  of 
gold  has  been  well  condensed  it  is  well  to  give  the  surface  a  thorough 
burnishing  for  the  purpose  of  getting  a  compact  surface  as  well  as  to 
insure  perfect  contact  with  the  margins  of  the  cavity. 

The  simple  fillings  upon  the  occlusal  surface  of  the  bicuspids  and 
molars  are  best  dressed  down  with  small  finishing  burs,  as  shown  in 

Fig.  209.  These  are  fine  cut  and  leave 
the  gold  with  a  better  surface  than  w^hen 
cavity  burs  are  used  for  this  purpose. 

The  gold  should  be  cut  away  until 
the  margin  of  the  cavity  has  been 
reached  and  until  all  overlapping  of 
gold  has  been  removed.  The  occlusion 
of  the  tooth  of  the  opposite  jaw  should 
be  noted,  and,  if  it  occludes  unduly  with 
the  filling,  enough  should  be  taken  from  the  surface  of  the  gold  to  pre- 
vent it.     When  a  uniform  surface  has  been  given  to  the  gold,  a  suitable 

Fig.  210. 


Fig.  209. 


Plug  finishing  burs. 


Wood  polishing  points. 


wood  point  as  shown  in  Fig.  210  should  be  mounted  in  an  engine  man- 
drel and  dipped  first  in  water  and  then  in  fine  pumice  powder  and  the 
surface  nicely  smoothed.  A  round-end  burnisher  may  be  used  if  the 
operator  desires  a  polished  surface,  although  it  adds  nothing  to  either 
the  beauty  or  the  utility  of  the  filling. 

When  fillings  cover  a  larger  portion  of  the  occlusal  surface  the  dress- 
ing down  may  be  done  with  corundum  or  carborundum  points,  which  if 
kept  wet  will  cut  more  rapidly  than  burs  and  cause  less  heating.  These 
are  shown  in  Fig.  211,  and  are  of  many  patterns  and  admirably  adapted 


254 


THE  OPERATIOS   oF  l-ILUM:    (AViriKS. 


to  all  parts  of  the  Hlliiitr.       Those   iiiadc  of  line  coiuikIiiiii   and   -licllac, 
or  coniiKliiin  and  vulcanized  riii)i)er,  are  more  desirable  than  the  coarse 


Fui.  211. 


Ciirundmn  point.- 


ones,  wliic-h  arc  liable  to  ^rvind  away  the  cavity  margins  because  of  the 
rapidity  with  which  they  cut. 

Fk;.  212. 


TTYY 


Ki< 


>13. 


o 


Felt  jKilisliing  wheels. 
Fig.  214. 


Iliiidostan  poiIlt^. 

Fillinirs  upon  labial  and  buccal  surfaces  .-hould  be  dressed  down 
with  fine  corundum  points  or  the  Hindostan 
stones  shown  in  Fig.  212  until  the  outline  of 
the  cavity  has  been  reached.  Any  overlap- 
ping of  the  gold  upon  th(\se  surfaces  gives  a 
ragged  a])pearance  to  the  filling  and  detracts 
much  from  its  beauty.  Care  should  also  be 
exercised  in  giving  the  filling  the  same  degree 
of  convexity  that  the  tooth  formerly  had  ;  in 
other  words,  the  filling  should  accurately  re- 
store the  lost  anatomical  contour  of  the  tooth. 

When  sufficient  gold  has  been  removed  the 
surface  should  be  nicely  smoothed  with  re- 
volving wood  points  charged  w^ith  pumice 
powder  and  water,  or  a  paste  made  of  pumice 
and  glycerin,  after  which  the  final  finish  may 
be  made  with  flour  of  pumice,  chalk,  or  ox  id 
of  tin,  used  l)v  means  of  a  revolving  disk  or 
wheel  of  felt  or  soft  rubber  (Fig.  2l3j.  The 
soft  rubber  polishing  cup  of  Dr.  John  15. 
Wood  is  a  valuable  aid  in  ])olisliing  the  con- 
vex surfaces  of  approximal  fillings  or  those 
upon  the  cervical  portion  of  labial  cavities. 
It  is  shown  in  Fig.  214.  As  fillings  upon  the 
labial  surface  are  more  or  less  conspicuous  at  best,  it  is  better  not  to 
give  them  a  burnished  surface.  The  dead  or  satin-like  finish  which  is 
left  by  the  flour  of  pumice  is  usually  preferred. 


Dr.  Wood's  polishing  cup. 


FINISHING  FILLINGS. 


255 


Fillings  upon  approximal  surfaces  are  more  difficult  to  finish,  and  too 
great  care  cannot  be  bestowed  upon  them.  An  operator  is  often  judged 
by  the  finish  which  he  gives  his  approximal  fillings,  and  justly  so,  as 
no  class  of  fillings  requires  a  higher  degree  of  skill  in  the  finishing. 

There  is  of  necessity  more  or  less  overlapping  of  the  gold  in  the 
insertion  of  a  filling,  and  the  removal  of  all  excess  is  as  important  as 
any  other  part  of  the  operation.  For  this  purpose  a  great  variety  of 
instruments  is  supplied.     Files  and  gold  trimmers,  as  shown  in  Figs. 


Fig.  215. 


:\  1 


Plug  finishing  files. 

215  and  216,  are  best  adapted.  The  cervical  border  is  one  which 
should  receive  most  careful  attention.  The  gold  should  be  filed  and 
dressed  down  until  the  finest  excavator  or  probe  will  not  catch  when 
drawn  from  the  cervix  toward  the  cutting  edge.     In  addition  to  the 

Fig.  216. 


Curved  finishing  files. 


file  and  gold  trimmer,  strips  of  emery  tape  or  sandpaper  should  be  used 
until  all  margins  are  well  defined.  The  oj)erator  should  have  at  hand 
a  great  variety  of  these  strips,  some  of  extreme  thinness  and  of  various 
grits,  of  emery,  of  silex,  and  of  buckhorn. 

When  the  filling  has  assumed  the  desired  shape  and  all  overlapping 
gold  has  been  removed,  the  final  finish  should  be  given  with  linen  or 


'2r>{] 


THE   OPERATION  OF  FILLING   CAVITIES. 


cotton  tajH'  c'luir^od  with   punuce  of  excoocling  fineness.      It"  thoro  arc 
places  where  the  tape  cannot  be  made  to  reach,  a  soft-rubber  wheel  in 


Via.  217. 


Approxiiiial  triiuiiiors. 

the  handpiece  of  the  engine  and  charged  with  the  same  powder  may 
be  used  (Fig.  218). 

Fillings  in  the  bicuspids  and  molars  because  of  their  inaccessible 
position  are  often  most  difficult  to  finish,  and  for  this  reason  should 
receive  unusual  care.  If  a  matrix  has  been  used  at  the  cervical  border, 
and  has  been  made  to  fit  the  tooth  perfectly  at  or  near  the  gum,  it 
will  be  found  that  the  finishing  process  has  been  simplified  in  a  great 
measure,  because  there  is  less  overlapping  of  the  gold  at  this  point. 

Frc.  218. 


>(iliruljln.'r  di^k^ 


The  pointed  files,  right  and  left,  as  shown  in  Fig.  216,  are  admirably 
adapted  to  dressing  away  any  overlapping  of  gold  at  the  cervical  border. 


Fir;.  219. 


With  these  and  the  trimmers  shown  in  Fig.  217  the  general  outline 
of  the  filling  may  be  oljtaincd.  after  which  the  emery  and  corundum 
tape  may  be  used  and  the  tilling  polished  after  the  same  manner  as 


FINISHING  FILLINGS.  257 

described  above.  Disks  of  sandpaper  and  emery  cloth  and  finer  ones 
chiarged  with  cuttlefish  powder  (Fig.  219)  are  exceedingly  useful  in 
shaping  and  polishing  the  filling.  Fig.  220  shows  two  forms  of  disk 
mandrels  which  may  be  satisfactorily  used  in  carrying  disks. 

Fig.  220. 


Morgan-Maxfleld  disk  mandrel. 


Many  approximal  fillings  in  the  bicuspids  and  molars  extend  to  the 
occlusal  surface.  When  this  is  the  case  the  operator  should  pay  special 
heed  to  the  occlusion  of  the  opposing  teeth.  If  left  too  full  the  con- 
stant touching  of  an  opposing  cusp  may  batter  the  filling,  or,  if  not 
securely  anchored,  dislodge  it.  A  filling  is  not  well  finished  until  a 
delicate  instrument  can  be  passed  from  enamel  surface  to  filling  with- 
out catching.  When  this  can  be  done,  and  dental  floss  is  not  frayed  at 
the  cervical  margin,  the  inference  is  justified  that  no  gold  has  been  left 
overlapping. 

Repairing  Fillings. 

Fillings  somewhat  defective  are  often  susceptible  of  repair.  The 
defect  may  sometimes  be  apparent  in  the  finishing ;  at  other  times  it 
is  the  result  of  subsequent  caries,  and  at  still  other  times  the  result  of  a 
fracture  of  the  tooth  enamel  along  the  border  of  the  filling. 

The  nature  of  the  defect  and  the  condition  of  the  remaining  filling 
must  be  taken  into  consideration  before  an  effort  to  repair  is  undertaken. 

When  the  defect  is  due  to  insufficient  gold  at  any  point  in  the  filling 
more  gold  may  be  added.  It  is  well  to  first  cut  out  a  portion  of  the 
filling,  making  a  distinct  cavity  of  retentive  shape.  Cohesive  gold  is 
usually  best  suited  to  the  purpose  ;  crystal  gold  often  serves  well  in 
the  repair  of  such  defects. 

If  the  filling  has  been  thoroughly  condensed  and  the  mass  is  solid 
there  is  little  difficulty  in  adding  more  gold  to  it,  provided  the  sur- 
face be  clean.  If  it  has  been  wet  with  saliva,  the  surface  of  the  gold 
must  be  made  not  only  dry  but  clean.  It  is  well  to  wipe  it  with  a 
pellet  of  cotton  or  paper  saturated  with  alcohol  or  ether,  after  which 
the  filling  should  be  scraped  with  a  suitable  instrument.  If  the  fill- 
ing be  of  considerable  size  and  well  anchored,  shallow  retaining  pits 
17 


258  THE   OPERATION  OF  FILLING   CAVITIES. 

may  bo  drilled  into  it,  which  will  make  an  additional  hold  for  the 
^old  which  is  to  be  added.  Defects  which  arise  from  snbse(|uent  caries 
are  perhaps  more  frequent  in  approxiniai  surfaces  at  or  near  the  cervical 
maririn.  These  borders  are  vulneral)le  points  for  the  recurrence  of 
caries,  and  imperfect  adai)tatiou  is  not  infrequently  the  determining 
cause  of  the  beginning  of  such  decay. 

To  effect  a  successful  repair  in  such  localities  am})le  space  should  be 
obtained,  especially  so  if  the  repair  is  to  be  made  with  gold. 

If  the  decay  has  not  extended  beneath  the  filling,  and  sufficient 
space  has  been  obtained,  there  is  no  greater  difficulty  in  making  a  suc- 
cessful repair  than  in  filling  a  simple  cavity  similarly  located.  If  the 
operator  is  skilled  in  the  use  of  non-cohesive  gold,  he  will  do  well  to 
prepare  his  foil  in  the  form  of  narrow  tape,  and  work  it  into  the  cavity 
fold  after  fold,  allowing  the  loops  to  extend  somewhat  above  the  walls 
of  the  cavity.  When  the  cavity  has  been  completely  filled  the  protru- 
ding folds  may  be  well  condensed  and  the  filling  finished  in  the  usual 
way  ;  or  the.  repair  may  be  made  with  cohesive  gold,  the  first  piece 
having  been  made  fast  in  a  groove  or  r(>taiuing  pit. 

Such  repairs  are  often  required  in  the  bicuspids  and  molars,  and 
large  fillings  otherwise  good  are  saved  by  a  successful  repair  at  the 
cervix.  The  plastics  are  sometimes  indicated  in  this  class  of  cases, 
provided  they  be  not  so  near  the  anterior  part  of  the  mouth  as  to  be 
unsightly.  Gutta-percha  often  serves  a  good  purpose  here,  but  in  some 
mouths  undergoes  decomposition  and  is  less  reliable  than  gold.  The 
oxyphosphates  are  contraiudicated  because  of  their  liability  to  wash 
away  after  a  few  months.  Amalgams  are  more  frequently  used,  and 
nearly  always  serve  well  when  thus  employed  ;  but  unfortunately  the 
contact  with  gold  produces  discoloration,  and  an  unsightly  filling  is  the 
result.  Whenever  gold  and  amalgam  are  brought  in  contact  in  the 
same  tooth,  if  the  surface  of  each  is  exposed  to  the  fluids  of  the  mouth, 
the  amalgam  is  almost  sure  to  turn  quite  black.  The  discoloration  of 
the  surface  of  the  alloy  does  not  lessen  its  value  as  a  j)reserver  of  the 
tooth,  but  its  unsightliness  is  often  too  great  to  be  tolerated  ;  nevertheless, 
utility  enters  so  largely  into  the  equation  that  the  operator  feels  justified 
in  using  the  alloy,  because  with  it  he  feels  sure  of  making  a  better  repair. 
After  the  alloy  has  hardened  it  should  be  nicely  dressed  down  and  all 
overlapping  of  the  material  at  the  gum  margin  removed,  when  it  should 
be  smoothed  and  polished  with  the  same  care  that  other  fillings  receive. 

Fracture  of  one  or  more  of  the  cavity  walls  is  a  common  accident, 
and  one  which  may  be  repaired  if  the  filling  has  been  securely  anchored 
in  portions  of  the  tooth  not  involved  in  the  fracture.  Such  accidents 
sometimes  befall  bicuspids  and  molars,  especially  the  bicuspids,  where 
fillings  have  b^'cn  inserted  in  each  aj)pr()ximal  surface,  the  two  meeting 


REPAIRING  FILLINGS.  259 

in  the  fissure  upon  the  occlusal  surface.  The  buccal  wall  is  sometimes 
the  one  broken  away,  sometimes  the  lingual.  In  either  case  the  ability 
to  successfully  repair  depends  upon  the  stability  of  the  approximal 
fillings  and  the  anchorage  which  can  be  obtained  at  the  cervical  w^all 
and  in  the  exposed  fillings.  To  restore  with  gold  a  buccal  cusp  or  the 
entire  buccal  surface  of  a  bicuspid  might  necessitate  a  show  of  gold 
which  would  be  objectionable ;  and  a  better  plan  would  be  to  engraft  a 
porcelain  facing  or  an  entire  porcelain  crown  ;  whereas  such  a  restora- 
tion on  the  lingual  surface  would  not  be  open  to  the  same  objections. 
Cohesive  gold  alone  is  indicated  for  repairs  of  this  kind.  Watts'  crystal 
gold  when  used  in  cases  of  this  description  has  been  most  satisfactory. 

If  the  fracture  extends  above  the  margin  of  the  gum  the  operation 
is  much  more  difficult  because  of  the  danger  from  a  flow  of  blood,  and 
the  additional  difficulty  of  getting  the  rubber  dam  above  the  border 
of  the  fractured  surface.  This  may  be  accomplished  by  filling  for  a 
few  weeks  with  gutta-percha,  when  there  will  be  recession  of  the  gum 
caused  by  the  pressure  of  the  gutta-percha  upon  it.  When  a  similar 
fracture  occurs  in  a  molar,  if  the  fractured  surface  does  not  encroach 
upon  the  pulp,  and  will  admit  of  drilling  retaining  pits  without  danger 
to  the  pulp,  there  is  no  difficulty  in  restoring  the  broken  portion  with 
cohesive  gold.  Mack's  screws  are  sometimes  indicated  in  cases  of  this 
kind,  since  strong  anchorage  can  be  secured  in  this  way  without  much 
loss  of  tooth  substance. 

Fracture  of  the  incisal  edge  of  the  anterior  teeth  is  often  a  serious 
accident,  because  of  the  difficulty  of  repair  and  the  unsightly  display 
of  gold  when  it  has  been  accomplished. 

Large  fillings  situated  upon  the  approximal  surfaces  of  the  incisors 
but  not  extending  to  the  cutting  edge,  yet  near  enough  to  weaken  the 
enamel  overhanging,  are  especially  liable  to  need  repairs.  The  corner 
of  the  tooth  breaks  away,  leaving  the  surface  of  the  gold  exposed,  and 
the  only  hold  the  filling  has  is  at  the  cervical  border.  In  order  to  secure 
retaining  hold  for  additional  gold  the  operator  must  be  careful  not  to 
displace  the  original  filling,  A  wooden  wedge  should  be  inserted  between 
the  teeth  and  pressed  home  with  sufficient  force  to  hold  the  filling  securely 
in  place  during  the  operation  of  repair.  Sometimes  a  retaining  pit  can 
be  made  laterally  into  the  sound  dentin,  or,  by  cutting  a  little  channel 
through  to  the  lingual  surface  and  then  deepening  the  channel  at  its  ex- 
tremity with  a  round  bur,  a  secure  anchorage  may  be  had  for  the  fresh 
gold. 

Great  care  should  be  exercised  in  packing  the  gold,  lest  by  inadver- 
tence the  instrument  should  slip  and  push  the  original  filling  from  its 
position.  Fractured  surfaces  should  receive  prompt  attention,  for  if  left 
for  a  period  of  time  disintegration  of  the  dentin  will  set  in   and  the 


260  THE  oPERArius  of  fiijjxg  cavities. 

caries  niav  extend  l)eneath  the  filling  and  thus  jeopardize  or  riiiii  the 
most  thorough  work. 

Eroded  Areas. 

There  is  a  ehis.s  of  cavities  wiiii-h  has  not  been  specitieally  treated  in 
the  foregoing  chapter,  partly  because  the  lesions  under  consideration 
cannot,  strictly  speaking,  be  classed  under  the  head  of  carious  cavities, 
and  thev  are  of  such  a  peculiar  formation  that  no  definite  rule  can  be 
laid  down  as  to  the  best  mode  of  treatment.  It'  the  eroded  area  be 
narrow  and  confined  to  the  cervical  border  of  the  labial  surface,  and 
in  a  mouth  in  which  the  teeth  are  not  conspicuous,  a  filling  of  gold 
may  be  employed ;  but  not  infrequently  the  eroded  area  extends  over 
a  considerable  portion  of  the  labial  surface,  and  in  such  cases  a  filling 
of  gold  would  be  so  inharmonious  that  it  should  be  avoided  if  possible. 
Hitherto  the  operator  has  had  little  choice  of  filling  materials,  and  has 
often  been  compelled,  against  his  better  judgment,  to  employ  gold  in 
these  cases. 

The  zinc  phosphates  have  been  almost  as  inharmonious  in  color  as 
the  gold,  and  their  dural)ility  has  been  so  variable  that  they  could  not 
be  regarded  as  permanent  in  character.  The  same  may  be  said  of  gutta- 
percha. 

Happily,  the  progress  which  is  being  made  in  porcelain  inlay  icork 
promises  something  both  artistic  and  durable.  It  is  quite  possible,  with 
the  great  variety  of  shades  of  porcelain  now  being  furnished,  to  match 
the  tint  of  the  natural  tooth,  and  if  care  be  exercised  in  the  selection  of 
shades  and  the  contour  given  to  the  inlay  these  eroded  areas  may  be 
covered  and  the  tooth  made  to  assume  almost  as  natural  an  appearance 
as  before  the  disease  had  attacked  the  surface.  (For  a  detailed  descrip- 
tion of  porcelain  inlays  the  reader  is  referred  to  Chapter  XV.) 


CHAPTER  XII. 

USE  OF  THE  MATRIX  IN  FILLING  OPERATIONS. 

By  William  Crenshaw,  D.  D.  S. 

The  matrix,  as  originally  suggested  and  employed,  was  used  exclu- 
sively between  the  molars  and  bicuspids,  and  consisted  of  curved  pieces 
of  thin  metal  of  various  kinds,  which  were  braced  with  wooden  wedges 
from  one  tooth  to  the  other  ;  but  now  the  matrix  has  been  adapted  to  other 
teeth  and  other  forms  of  cavities,  as  will  appear  in  the  further  develop- 
ment of  this  subject.  All  forms  of  cavities  occurring  on  molars,  bicus- 
pids, and  incisors,  standing  alone  or  together,  excepting  those  cavities 
located  in  the  occlusal  surfaces  of  the  first-mentioned  class,  and  in  the 
cutting  edges  and  corners  of  the  latter,  are  now  subject  to  the  use  of  the 
matrix  as  an  aid  in  filling  them. 

The  large  and  difficult  filling  operations  encountered  between  the 
molars  and  bicuspids,  which  in  past  decades  so  taxed  the  skill  and  vitality 
of  the  dentist,  have  been  by  various  forms  of  device  rendered  easier  of 
execution  and  more  permanent  and  perfect  in  character. 

Matrices  have  been  used  more  or  less  in  one  form  or  another  for  the 
past  fifty  years  and  some  crude  forms  even  longer.  Dr.  Louis  Jack  gave 
the  profession  thirty  years  ago  the  first  practical  idea  and  demonstration 
of  the  matrix  and  its  possibilities,  and  his  effort,  more  than  all  that  had 
gone  before,  gave  shape  and  impetus  to  the  development  of  this  important 
device. 

General  Considerations. 

The  limitations,  no  less  than  the  possibilities,  of  the  matrix  are  im- 
portant to  understand,  because,  used  indiscreetly,  in  locations  which  the 
judgment  should  forbid  or  in  locations  where  it  would  be  perfectly  in 
place  but  for  the  unsuitable  nature  of  the  material  employed,  more  harm 
than  good  may  result  from  its  use.  To  be  able,  therefore,  to  discern  the 
proper  class  and  location  of  cavities  for  the  reception  of  the  fillings, 
together  with  a  knowledge  of  adapting  the  filling  materials  to  the  case 
in  hand,  are  some  of  the  requirements  and  demands  on  the  operator  who 
essays  to  use  matrices. 

The  matrix  should  possess  as  fully  as  possible  the  qualities  of  adapt- 
ability and  fixedness  to  the  teeth,  at  the  same  time  provide  for  contouring 
and   for  leaving  the  teeth  in  proper  position,  and  preserving  the  proper 

261 


262  USE  OF  THE   MATRIX  IX  FILLIXG   OPERATIOXS. 

intcr])i\)xiiual  !^j)aro.  Further  (It'siclcrata  arc  that  the  matrix  sliall  be 
resistant  cnougli  t(»  .<taiul  tlie  pressure  of  condensing  gold  against  it, 
susceptible  at  the  same  lime  of  being  shaped  into  whatever  form  needed, 
and  capable  of  being  removed  from  between  the  teeth  without  destroy- 
ing the  ibrm  of  the  tilling  after  liial  has  been  completed. 

The  material  of  which  the  matrix  is  made  depends  somewhat  on  the 
location  and  class  of  the  cavity  to  be  filled. 

In  many  of  the  operations  occurring  between  molars  and  bicuspids, 
particulariv  in  the  instances  where  only  one  tooth  is  decayed  and  only 
siiglitly  so,  slips  of  German  silver  or  steel  (36  to  40  gauge)  may  be  inter- 
posed and  used.  In  the  instances  where  gold  is  to  l)ethe  tilling,  and  the 
cavity  is  t)f  large  size,  the  metals  above  mentioned,  silver  and  gold  |)late, 
but  of  heavier  gauge,  and  other  substances  may  be  employed.  But  in 
the  event  of  the  matrix  band  having  to  bear  heavy  tension,  which  tests  the 
strength  of  it,  as  in  the  loop  or  band  variety  or  any  duplex  form  which 
separates  the  teeth,  either  decarbonized  steel  or  phosphor-bronze,  the  ten- 
sile strength  of  which  is  equal  to  or  beyond  that  of  steel,  should  be  used. 
Steel  is  somewhat  unsatisfactory,  because  if  bent  often  at  one  place  it 
breaks,  and  it  does  not  hold  polish  or  plating  well.  Phosphor-bronze 
not  only  polishes  and  holds  plating  well,  and  does  not  corrode,  but  solders 
readilv  to  gold,  silver,  German  silver,  steel,  copper,  and  brass,  and  does 
not  soften  or  amalgamate  with  the  mercury  employed  in  amalgam  alloys. 

The  matrix  band  should  be  closely  ada])ted  around  the  margin  of  the 
tooth  cavity,  and  the  cavity  floor  and  walls  coming  up  to  the  band 
should  form  as  nearly  as  possible  right  angles  with  the  band.  This  rule 
followed,  with  the  employment  of  proper  forms  of  instnmients,  will  be 
found  to  insure  well-condensed  margins,  and  as  full  a  contour  as  ordi- 
narily belongs  to  the  tooth  of  its  class  ;  and,  in  those  instances  where  it  is 
desirable,  greater  contour  than  belongs  to  the  tooth  may  be  produced. 

Those  devices  which  when  assembled  are  practically  in  one  piece,  and 
admit  of  easy  application  and  steady  fixedness  on  the  teeth,  with  as  little 
of  obstructing  parts  as  possible,  are  the  ones  with  which  the  0})erator 
will  ordinarily  accomplish  best  results.  The  bands  should  not  purposely 
stand  awav  from  the  tooth.  This  is  impracticable  even  if  it  were  desirable, 
as  there  are  no  means  for  holding  the  band  away  from  the  tooth  and  at_the 
same  time  having  it  secure  from  slipping  and  working  loose  under  the 
operation  of  the  filling.  Occasionally  in  cavities  occurring  on  the  mesial 
side  of  upper  first  and  second  molars,  and  more  frequently  on  both  the 
mesial  and  distal  sides  of  upper  first  bicuspids  extending  well  under  the 
gum,  we  encounter  the  concavity  occasioned  by  the  bifurcation  of 
the  roots,  when  of  necessity  the  band  stands  off  from  the  depression. 
The  filling,  however,  whether  of  gold  or  tin-foil,  is  not  better  condensed 
at  this  point  for  that  reason. 


GENERAL   CONSIDERATIONS.  263 

The  failures  made  with  the  matrix  result  quite  frequently  from  the 
selection  of  a  wrong  material.  Take,  for  instance,  any  of  the  approximal 
surfaces  of  the  molars  or  bicuspids  in  which  the  cavity  extends  beyond 
the  margin  of  the  enamel,  presenting  ideal  conditions  for  the  employment 
of  the  matrix ;  prepare  these  cavities  after  approved  methods,  apply  the 
matrix,  and  fill  with  any  form  of  cohesive  gold,  and  we  have  a  filling 
beautiful  in  appearance,  but  more  treacherous  than  beautiful,  and  one 
which  will  develop  recurrent  decay  along  the  cervical  margin  sooner  than 
would  result  from  the  employment  of  any  other  filling  material  placed 
in  the  permanent  list. 

It  will  not  matter  what  form  of  cohesive  gold  is  employed,  if  heat 
sufficient  to  change  its  molecular  arrangement  has  been  applied  in  annealing 
the  gold,  it  is  practically  impossible  to  adapt  it,  unaccompanied  by  linings, 
so  as  to  secure  moisture-proof  joints,  and  therefore  permanent  results. 
Because,  first,  the  tooth  does  not  affi^rd  the  resistance  necessary  to  reduce 
the  crystals  of  gold  into  adaptable  laminae,  and  we  have  the  crystalline 
gold  resting  on  fibrous  structure  in  the  cementum  and  dentin,  which 
together  prevent  the  making  of  moisture-proof  joints.  Therefore  this 
state  of  affairs,  aided  either  by  the  seeping  in  of  fluid  at  the  base  of  the 
filling  from  the  canaliculi  and  lacunae,  or  drawing  in  external  moisture 
by  capillary  attraction  from  without,  permits  of  recurrent  decay.  With 
cohesive  gold,  the  result  would  be  ultimately  the  same,  with  or  without 
the  matrix ;  although  the  work  would,  should  at  least,  be  better  executed 
without  it.  But  with  the  cavity  well  prepared,  and  the  matrix  securely 
adjusted,  the  operation  is  inviting  in  appearance,  and  the  operator  is  led 
into  a  snare  and  delusion  when  he  essays  to  fill  these  points  with  cohesive 
gold  exclusively. 

The  objection  here  raised  to  cohesive  gold  does  not  apply  to  the  same 
extent  in  adapting  it  to  enamel  walls,  because  in  this  tissue  we  have  an 
absence  of  nerve-fibres,  and  a  greatly  denser  substance  against  which  to 
adapt  the  gold.  While  it  is  impossible  to  adapt  cohesive  gold  to  tooth 
structures  so  as  to  stop  out  moisture  permanently,  for  the  reason  pointed 
out,  there  is  that  difierence  in  the  histological  make-up  of  the  tissue  of 
cementum  and  dentin  and  enamel  which  explains  the  fact  of  cohesive 
gold  being  better  adapted  to  enamel,  and  can  be  made  to  better  prevent 
the  leaking  of  moisture  than  in  cementum  margins.  Again,  decay  cannot 
be  so  rapid  in  enamel  margins,  because  of  its  inherent  strength  and  re- 
sistance, due  in  part  to  the  absence  of  nerve-fibres  and  to  its  greater 
density  and  hardness. 

The  propaganda  of  Prof,  Henry  S.  Chase — namely,  that  in  propor- 
tion as  teeth  need  saving  gold  is  the  worst  material  with  which  to  do  it — 
is  true  in  its  application  to  cohesive  gold,  particulary  in  cementum  and 
dentin  margins  in  connection  with  the  matrix.      But,   substitute  non- 


2<)4  USl-:  OF   THE  MAT/UX    l\   l-ILIJSd    OPERATIONS. 

iTVstalliiU'  or  .soil  gold  in  llioc  iii:ir<:iii>,  and  \vc  pass  Iroiii  the  worst 
possible  work  doiu'  witli  ii:old,  and  made  even  worse  hy  tlic  employment 
of  the  matrix,  to  that  which  has  prove<l  the  West  j)ossihl( — at  least  up  to 
the  present  time. 

Cohesive  gold  is  at  its  Ix'st  in  open  cavities  with  .-trong  enamel  mar- 
gins, and  is  protitably  employed  in  eervieo-oi-elnsal  fillings  in  connection 
with  soft  gold  and  matrices  to  cap  over  the  approximal  wall  of  soft  gold. 
Cohesive  gold,  on  the  other  iiand,  is  at  its  worst  in  connection  with 
matrices  when  used  at  the  cervical  margins,  particnlaily  when  the  margin 
is  located  in  cementnm  or  dentin,  because  of  the  physical  difficulties 
encountered  in  the  adaptation  of  it,  and  the  perishable  nature  of  the 
margins  on  which  it  is  laid. 

Again,  in  the  employment  of  a  carelessly  formulated  and  com- 
pounded amalgam  alloy  packed  into  these  cavities  embraced  l)y  a 
matrix,  depending  too  much  on  the  matrix,  as  the  tendency  is,  we  have 
another  instance  in  which  the  inefficiency  of  this  device  is  made  to 
appear. 

It  should  be  made  a  rule  of  practice  in  employing  the  matrix  to  regard 
it  simply  as  a  mechanical  device,  the  object  of  which  is  to  simplify  com- 
pound and  other  difficult  cavities ;  and  not  to  depend  on  it  to  make  good 
any  of  the  essentials  of  the  filling  material.  With  this  idea  in  view,  and 
fortified  by  a  knowledge  of  the  essential  characteristics  of  materials  rather 
than  matrices,  we  shall  know  where  and  when  to  employ  them.  The 
filling  materials,  too,  must  possess  constancy  of  form,  and  susceptibility  to 
that  perfect  adaptation  which  shall  prevent  the  drawing  in  of  moisture  by 
capillary  attraction,  the  result  of  which  would  l)e  recurrent  decay.  An 
understanding  of  these  characteristics  is  indispensable  to  the  permanence 
of  filling  operations  anywhere  and  everywhere,  and  by  whatever  method 
performed,  and  when  they  are  thus  understood,  combined  with  the 
advantages  afforded  in  the  use  of  the  matrix,  the  operator  will  accomplish 
his  best  results.  The  matrix  should  be  used,  therefore,  for  the  'purpose 
of  simplifying  the  cavity,  and  never  allowed  to  lead  into  the  use  of  a 
treacherous  and  questionable  material. 

The  matrix  is  valuable  in  all  those  cavities  of  extreme  decay  involving 
the  disto-occlusal,  the  raesio-occlusal,  the  bucco-occlusal,  the  disto-bucco, 
the  mesio-bucco,  and  the  disto-linguo  and  mesio-linguo  occlusal  surfaces 
of  molars  and  bicuspids.  In  many  instances  the  entire  corners  may  be 
restored,  as  is  intimated  and  included  in  the  disto-bucco  and  mesio-bucco, 
the  disto-linguo  and  mesio-linguo-ocelusal  surfaces.  No  method  yet 
devised  for  filling  these  teeth  is  so  satisfactory  or  productive  of  such 
results  as  when  the  matrix  is  employed,  as  it  aids  the  adaptation  of  the 
material  definitely  and  exactly  in  position.  Its  chief  advantage  is  in 
having  brought  a  cavity  of  compound  and  complex  nature  into  simple 


GENERAL  CONSIDERATIONS.  265 

form,  and  so  contributing  to  the  mastery  of  the  material  that  perfect 
adaptation  and  condensation  is  secured. 

A  comparison  of  results  at  the  cervical  margin  between  fillings  made 
of  soft  gold  and  those  of  the  cohesive  variety  shows  in  so  marked  a 
deo-ree  in  favor  of  the  soft,  even  in  operations  where  tlie  matrix  has  not 
been  used,  that  when  this  device  is  employed  it  places  the  standard  of 
excellence  of  soft-gold  work  far  beyond  that  of  the  cohesive. 

With  the  advantages  thus  accruing,  soft  gold  in  the  form  of  cushions 
or  cylinders  may  be  perfectly  adapted  at  the  cervical  aspect  and  as  far  up 
the  wall  as  desired,  capping  over  with  a  slab  of  cohesive  which,  when 
anchored  in  the  occlusal  surface,  makes  a  handsome  and  lasting  operation. 

Another  treatment  of  these  cavities  is  to  place  tin  cylinders  or  cush- 
ions, which  may  be  made  by  folding  the  cylinders  upon  themselves,  and 
adapt  at  the  cervical  margin  and  up  the  cervico-occlusal  wall  to  the  top 
of  the  step  d,  Fig.  221,  completing  with, the  slab  of  cohesive  gold  or  of 
amalgam  for  the  remainder  of  the  filling.  (See  Fig.  225.)  The  soft 
gold  and  the  tin  are  practically  the  same  in  adaptation,  due  to  the  fact 
that  in  their  manufacture  the  molecular  arrangement  is  destroyed  and 
becomes  structureless,  by  which  a  closer  and  more  perfect  adaptation  is 
possible.  The  matrix  enables  the  operator  to  take  advantage  of  this 
important  quality  ;  and  without  thus  simplifying  the  cavity,  it  would 
be  quite  impossible  to  confine,  control,  and  condense  these  materials,  and 
secure  adequate  solidity  and  adaptation  to  margins. 

The  use  of  the  matrix,  therefore,  not  only  enables  the  operator  to 
place  soft  gold  in  a  satisfactory  manner  at  the  points  where  it  serves  best, 
but  also  cohesive  gold  where  it  is  best  adapted — namely,  at  enamel  mar- 
gins, and  in  that  portion  of  the  filling  where  it  is  most  easily  and  perfectly 
adapted.  Again,  cohesive  gold  is  placed  in  matrix  work  at  that  point 
where  it  best  resists  the  attrition  and  stress  of  chewing,  and  the  lateral 
wear  between  the  teeth. 

Still  another  treatment  of  these  cavities  in  connection  with  the  matrix 
is  with  amalgam  alloy. 

Assuming  that  the  same  care  and  pains  have  been  taken  with  the 
preparation  of  the  cavity  for  the  amalgam  as  for  the  gold,  the  simplifying 
of  it  by  the  use  of  the  matrix  enables  the  operator  to  secure  greater 
solidity  and  correspondingly  better  adaptation  to  the  walls  of  the  cavity. 
This  material,  used  in  connection  with  the  matrix  and  cavity  lining, 
places  amalgam  alloy  on  a  plane  not  heretofore  occupied  by  it.  In  the 
large  proportion  of  cavities  occurring  in  the  class  under  consideration,  this 
practice  stands  for  much  in  the  saving  of  these  teeth. 


266 


USE  OF  THE  MATRIX  IN  FILLISG   OPERATIONS. 


Cavity  Preparation  of  the  Major  Class  for  Matrix  Work. 

The  r^ubject  of  cavity  pirj)arati(in  comes  uj»  in  coiiiRrti(tii  with  tiiL' 
matrix  as  a  matter  of*  first  importance. 

The  form  of  cavity  preparation  ordinarily  employed  in  cases  of  extreme 
decay  of  approxinial  surfaces  of  molars  and  bicuspids  answers  in  some 
measure  in  matrix  work. 

In  the  description  of  cavity  preparation  the  terms  depth,  width,  and 
length,  as  a]>plied  to  the  several  walls  of  the  cavity,  should  be  limited, 
and  apply  to  particular  points,  and  particular  points  only.  For  instance, 
the  depth  of  a  cavity  should  mean  from  the  point  of  decay  toward  the 
pulp,  whether  })enetrating  from  the  occulusal,  mesial,  distal,  buccal,  or 
lingual  aspect  of  the  tooth.  The  width  should  mean  from  side  to  side 
of  the  cavity,  whether  on  the  occlusal,  mesial,  distal,  buccal,  or  lingual 
surface  of  the  tooth.  The  length,  the  longest  dimension,  should  mean 
the  greatest  length,  in  whatever  direction  it  extends.  The  bottom  of 
a  cavity  should  be  called  the  floor,  as  seen  at  A  and  D,  Fig.  221.  By 
reference  to  Figs.  221  and  222  the  tooth  shown  represents  a  left  lower 


Fig.  221. 


Fig.  222. 


Fig.  223. 


E 

'N 


Cavity  preparation  of  a  molar       Cavity  preparation,  showing       Section  of  molar,  showing  the 
for  the  matrix.  siiuare  corners.  introduction  of  the  cushion. 

molar,  the  decay  of  which  penetrates  frt»m  the  mesial  surface  in  the 
direction  of  the  line  leading  from  F,  and  we  would  say  that  the  depth 
of  the  cavitv  seen  at  A  and  c  was  in  that  direction  ;  and  that  its  width 
was  bucco-lingual,  from  E  to  E,  or  from  c  on  the  buccal  side  to  a  point 
opposite  on  the  lingual.  This  cavity,  being  a  compound  one,  must  have 
added  together  for  its  length,  the  floor  of  the  step  i),  the  axial  wall  F,  and 
the  floor  A.  The  depth  of  the  lingual  and  buccal  walls  is  seen  at  C,  and 
the  depth  of  the  floor  at  A.  The  axial  wall  and  height  of  it  is  seen  at 
F,  and  the  floor  of  the  step  at  D. 

In  Fig.  221  is  represented  the  cavity  preparation,  with  which,  in 
connection  with  the  matrix  and  soft  and  cohesive  gold,  the  operator  is 
enabled  to  bring  gold  work  in  cavities  of  this  class  to  a  degree  of  per- 
fection rarely  approximated  without  its  aid. 

At  the  cervical  margin  of  Figs.  221  and  222  it  will  be  observed  that 


CAVITY  PREPARATION  OF  MAJOR  CLASS  FOR  MATRIX  WORK.   267 


the  floor  of  this  aspect  of  the  cavity,  A,  and  the  external  wall  of  the 
tooth,  B,  form  practically  right  angles,  which  is  the  angle,  all  things 
considered,  with  which  to  secure  the  best  margins  and  best  results. 

Beginning  well  up  on  the  side  wall  at  C,  Fig.  221,  passing  down  and 
along  the  base  of  the  cement  step  and  up  the  opposite  wall,  is  a  groove 
c,  better  shown  in  the  sectional  cut.  Fig.  223,  made  with  a  No.  3  or  4 
round  bur,  or  Darby-Perry  excavator,  Nos.  11  and  12,  designed  as  an 
anchorage  for  the  base  of  the  cervico-occlusal  column,  marked  non- 
cohesive  gold,  Fig.  225.  In  this  groove,  which  should  be  shallow  and 
upon  the  floor  surface.  A,  is  condensed  the  gold.  The  groove  extending 
up  the  side  wall  is  not  a  necessity,  though  it  may  be  incorporated  in  the 
cavity  formation  when  the  w^alls  are  strong,  but  that  portion  of  it  along 
the  floor  should  be  employed. 

In  the  instances  where  the  lateral  walls  are  weak  and  the  groove 
cannot  be  formed,  the  occlusal  anchorage  shown  at  d,  Figs.  221  and  222, 
should  be  employed.  In  the  formation  of  the  side-wall  edges,  e  e.  Fig. 
222,  care  must  be  taken  to  leave  them  strong  enough  to  prevent  fracture 
under  the  pressure  of  the  matrix  band.  These  walls  should  be  beveled 
on  the  lines  e  e,  Fig.  222,  terminating  in  an  obtuse  angle  with  the 
external  surface  of  the  tooth,  if  practicable.  Less  than  a  right  angle 
should  not  be  depended  on,  if  it  can  be  avoided,  as  there  is  danger  of 
fracture. 

In  the  formation  of  the  cavity  in  Fig.  221,  with  the  rounded  corner 


Fig.  224. 


A— -^ 


Fig.  225. 


COHESIVE  GOLD. 


CEMENT. 
NIOKI  COHESIVE  GOLD. 


Fig.  226. 


Cavity   preparation,    showing 
subdivisions  of  filling. 


Section  showing  the  plan  of  a       Section  showing  the  condensa- 
matrix  filling.  tion  of  cushion  k  of  Fig.  223. 


C,  is  seen  the  preparation  suitable  for  amalgam  or  other  plastic  materials 
in  connection  with  the  matrix  ;  and  for  cushions  and  cylinders  of  foil  if 
the  cavity  approximates  the  form  seen  in  this  and  Fig.  222,  and  at  F  and 
H  of  Fig.  226.  But  these  corners  should  be  modified  as  nearly  as  possi- 
ble into  the  form  seen  at  N  N,  Fig.  222,  if  the  cavity  is  shallower  from  A 
to  D,  Fig.  222,  than  from  F  to  h.  Fig.  226. 

The  square  corners  aid  in  better  locking  and  binding  the  foundation 
subdivisions  in  the  process  of  building  in  the  filling — see  Fig.  224. 

But  when  the  cavity  assumes  the  proportions  seen  at  F  to  H,  Fig.  226, 
the  matter  of  square  corners  is  not  necessary,  because  when  the  distance 


2HH 


USK  OF   Tin-:   .VATRIX    /.V    hll.LISd    < il'KllATK >SS. 


f'ntni  tlic  tn|)  nt'  the  f^tcp,  Fij;.  2li<),  In  the  Moor  is  nrrcatcr  tlmii  from  i'  (in 
the  axial  \\:ill  lo  H  ou  the  matrix  Itand,  \\v  have  a  form  of  cavity  in  wliicli 
the  ousliioii.-?  an<l  cylinders  hind  and  hold  without  the  aid  oi"  s(jnarc 
corners. 

It  should  he  a  rule  ol"  |)ractice  to  i»ut  in  cement  >te|)>  whenever  the  dis- 
tance from  the  axial  wall  to  the  njatrix  hand  is  jrreater  tiian  from  the  top 
of  the  step  lo  the  fl(»or  of  tlie  cavity,  and  hring  the  form  of  the  cavitv  as 
nearly  as  possible  into  that  shown  in  Figs.  22.'i,  22<j,  227,  and  229.  Be- 
cause, first,  it  necessitates  the  use  of  less  metal,  whetiier  of  gold  or  tin  ; 
second,  it  is  better  when  finished,  and  m(»re  (piickly  filled  to  the  toj)  of 
the  step,  Fig.  227  ;  and,  third,  it  avoids  the  formation  of  the  square 
corners,  n  n,  Fig.  222, extending  so  deej^ly  t(»ward  the  pulp  as  to  weaken 
the  walls  of  the  tooth. 


Fig.  22 


Fk;.  228. 


Peotioii  sliowiiisjcervico-occlu- 
sal  wall  built  to  lop  of  .«tep. 
(.,  groove  for  the  grasp  of  the 
capping  slab. 


Section  of  pul]>U'ss  molar  t)e- 
fore  placing  in  the  cement 
step. 


RF. 

Section  showing  the  recon- 
struction of  pulples.s  molar 
with  cement  step. 


In  the  introduction  of  the  filling  into  the  corners  of  Fig.  222,  the 
method  suggested  is  to  carry  in  the  cushion  of  .soft  gold  or  tin,  as  the 
case  may  be,  and  place  in  the  corner  at  a  with  pluggers,  Nos.  257,  258, 
or  259,  Fig.  265,  whatever  size  of  these  forms  shall  best  suit  the  case, 
and  partially  condense  it.  In  the  opposite  corner  place  in  the  subdivi- 
sion B,  and  then  the  subdivision  c.  Only  this  last  introduction  is  carried 
straight  down  in  the  direction  of  the  long  axis  of  the  tooth,  while  the 
other  subdivisions,  as  seen  in  Fig.  224,  are  placed  in  diagonally  and 
compressed  in  ])lace.  At  this  juncture  hold  down  with  a  suitably  shaped 
instrument,  Xo.  174  or  175,  F^ig.  265,  on  one  side  and  condense  the  other 
with  the  automatic  mallet  carrying  a  .suitalily  shaped  plugger.  No.  18, 
Fig,  265,  until  adequately  condensed.  After  this,  change  in.struments 
about,  and  treat  the  opposite  side  in  a  similar  manner.  If  the  cushions 
are  proportioned  properly  to  the  size  of  the  cavity,  two  sets  of  each  of  these 
put  into  the  subdivisions  A,  B,  and  r,  Fig.  224,  will  bring  the  wall  to  the 
top  of  the  step,  or  nearly  so. 

Fig.  221  represents  the  preparation  of  decay  cavities,  whether  appear- 
ing on  bicuspids  or  molars,  the  outer  outline  of  which  appears  in  Fig. 
230  and  comes  imder  the  head  of  the  major  class.     All   such  decay.= 


CAVITY  PREPARATIOX  OF  MAJOR   CLASS  FOR  MATRIX  WORK.   269 

should  as  nearly  as  practicable  be  prepared  after  the  suggestions  of 
Fig,  221. 

In  the  formation  of  the  cavity  in  Fig.  221,  when  the  tooth  is  normal 
and  its  functions  comfortably  performed,  care  must  be  exercised  to  avoid 
too  near  approach  to  the  pulp,  particularly  when  the  cavity  is  located  in 
bicuspids,  in  which  case  we  have  a  shallower  zone  in  which  to  work  than 
is  found  in  the  corresponding  parts  of  molars.  In  the  deeper  cavities  of 
bicuspids  and  molars,  zinc  phosphate  should  be  used  to  bring  the  cavity 
into  simple  form,  as  seen  in  Figs.  225,  228,  and  229. 

When  these  cavities  are  prepared  after  the  suggestions  and  illustra- 
tions of  the  figures  referred  to  and  embraced  by  the  matrix,  not  onlv  is 
less  material  needed  to  bring  up  the  cervico-occlusal  wall  to  the  top  of  the 
step,  but  additional  advantages  are  gained  in  that  the  cavity  is  simpli- 
fied, the  filling  rendered  easy  of  execution,  and  the  character  of  the  work 
improved. 

Oxyphosphate  of  copper  cement,  being  more  adhesive  and  less  a 
thermal  conductor,  and  possessing  more  of  antiseptic  property  than  the 
other  forms  of  zinc  cements,  should  be  employed  wherever  practicable 
for  step  making.  Its  inky  blackness  perhaps  is  against  its  use  in  the 
anterior  teeth,  and  farther  forward  than  the  molars.  But  it  is  also  less 
irritant  and  is  harder  and  stronger  than  any  of  the  zinc  phosphates. 

So  that,  in  the  insta:nces  where  the  cavity  penetrates  to  or  beyond  the 
pulp,  and  compels  the  formation  of  a  cavity  as  deep  from  the  matrix 
band  to  the  axial  wall,  as  is  shown  in  the  pulpless  tooth,  Fig.  228,  or  as 
already  cited,  when  the  depth  of  the  cavity  from  f  to  h,  Fig.  226,  is 
greater  than  the  height  of  the  step,  the  cement  should  be  placed  in  posi- 
tion to  bring:  the  axial  M'all  close  enough  to  the  matrix  band  to  form  the 
cavity  into  the  proportions  shown  in  Figs.  223,  226,  and  227  when  em- 
braced by  the  matrix. 

This  class  of  cavities,  when  filled  with  guld,  should  be  filled  with  soft 
gold  cushions  or  cylinders  to  the  top  of  the  step  D,  Figs.  221  and  222, 
when,  after  forming  the  groove  shown  at  G,  Figs.  225  and  227,  shuuld 
be  completed  with  cohesive  gold  and  built  seeurelv  in  place.  The 
anchorage.  Figs.  221,  222,  and  224  at  d,  indicate,  what  this  should  be. 

The  procedure  in  the  intnjduction  of  the  soft-gold  part,  or  of  tin  when 
that  is  used,  in  the  major  class,  is  seen  at  k,  Fig.  223,  and  when  con- 
densed, at  L,  Fig.  226.  The  introduction  is  in  the  direction  of  the 
long  axis  of  the  tooth  and  not  diagonal,  as  shown  in  Fig.  224.  though 
the  diagonal  introduction  may  be  employed  in  special  cases  favoring  it. 
The  cushions  thtis  introduced,  rarely  less  in  size  and  bulk  than  a  size  3 
cylinder,  and  generally  much  larger,  do  not  fill  up  squarely  out  to  their 
ends  or  to  the  lateral  walls  ;  and  the  operator  must  look  to  these  points, 
and  level  them  up  with  small  cylinders  or  their  equivalent  in  cushions. 


270  USE  OF   THE  MATRIX  IN  FILLING    OPERATIONS. 

The  final  condensing  of  this  column  as  seen  at  i,  Fig.  227,  and  before 
the  cohesive  ]xirt  is  begun,  shouhl  l)e  done  by  lioUling  down  the  gold 
at  one  side  of  the  cavity,  while  the  automatic  mallet  condenses  at  the 
opposite,  as  suggested  in  the  tilling  of  the  cavity  of  Fig.  222.  Tiie 
student  nuist  appreciate  the  importance  of  condensing  first  the  soft  and 
afterward  the  cohesive  gold  into  the  angles  formed  at  k  and  .\,  l^'ig.  222, 
when  that  figure  is  embraced  by  the  matrix.  Pluggers  Nos.  7  or  8,  Fig. 
265,  of  small  treading  surface  are  suitable  for  doing  this  part  of  the  work. 
The  cohesive  gold  should  be  used  in  narrow  strips  when  the  angle  into 
which  it  must  go  is  close  and  sharp. 

It  is  the  purpose  in  engineering  construction  to  secure  the  greatest 
possible  strength  from  the  arrangement  of  material  entering  into  such 
construction.  In  the  formation,  theref()re,  of  tiie  anchorage  for  the  fill- 
ings of  the  major  class  of  the  cervico-occlusal  cavities,  due  regard  nuist 
be  given  to  the  proportion  of  gold  and  enamel  in  making  the  anchorage 
head  in  the  occlusal  surface  of  fillings  of  this  class. 

Just  as  it  is  possible  to  weaken  a  carriage  wheel  by  having  the  tenons 
of  the  spokes  so  large  as  to  weaken  the  hub,  it  is  also  possible  to  have 
the  tenons  so  small  and  the  hub  so  strong  as  from  this  cause  to  weaken 
the  wheel.  So  also  with  tiie  anchorage  of  this  class  of  fillings  ;  the  neck 
of  gold  going  into  the  head  of  the  anchorage  may  i)e  so  small,  narrow, 
and  shallow  that  the  stress  of  chewing  will  cause  it  to  break  at  this  point. 
And  yet  the  neck  may  be  widened  and  deepened  so  much  that  the  gold 
becomes  stronger  than  is  necessary,  and  the  enamel  on  either  side  becomes 
correspond inglv  weak,  and  gives  way  under  stress  of  mastication. 

The  problem  then  is  to  proportion  the  neck  of  gold  and  the  enamel  so 
as  to  secure  the  greatest  strength. 

Assuming  the  depth  of  the  gold  neck  to  be  about  its  width,  the  rule 
of  one-third  gold  in  width  and  two-thirds  enamel,  one-third  each  side 
of  the  gold,  answers  the  requirement. 

The  Minor  Class. 
While  the  principles  inculcated  by  Drs.  Webb,  Black,  and  others  in 
extension  for  prevention— extending  the  cavity  margins  well  away  from 
the  contact  point  of  the  teeth — hold  good  in  the  larger  proportion  of  cases, 
there  are  those  individual  instances  presenting  when  the  operator  will  not 
be  justified  in  employing  extension  for  prevention.  Take,  for  instance, 
the  highly  developed  teeth,  with  perfectly  fused  enamel  through  the 
sulci  dividing  the  cones,  lobes,  and  cus]is  of  the  molars  and  bicuspids, 
which  from  the  excellence  of  their  quality  and  the  cleanliness  of  the 
patient  almost  entirely  prevent  caries  ;  it  would  be  unwise  and  untieces- 
sarv  under  these  conditions  to  extend  in  preparation  the  borders  of  these 
cavities  to  the  limits  taught  and  endorsed  in  extension  for  prevention,  and 


THE  MINOR   CLASS. 


271 


yet  so  necessary  in  many  of  the  larger  decays  denominated  the  major 
class. 

The  preparation  of  the  minor  class  of  decays,  represented  in  the  inner 
outline  of  Fig.  230,  should  be  formed  after  the  suggestions  of  Figs.  231 
232,  and  233.  The  student  should  comprehend  the  formation  of  both 
the  major  and  minor  class,  as  each  must  be  prepared  according  to  the 
suggestions  made. 

The  preparation,  therefore,  for  the  minor  class  may  be  enlarged  to  the 

Fig.  230.  Fig.  231.  Fig.  232. 


Bicuspid,  showing  the  major 
and  minor  class  cavity  out- 
line. 


Side  view,  showing  the  out- 
line of  the  major  and  minor 
preparation. 


Transaxial  section,  showing 
anchorage  of  the  minor  class 
at  line  a  of  Fig.  231. 


proportions  shown  in  the  inner  outline  of  Fig.  231,  while  the  outer  out- 
line of  Figs.  231  and  233  would  show  the  formation  of  the  major  class 
on  the  same  tooth. 

Fig.  234  is  a  sectional  cut  showing  the  completed  major  class  of 
the  cervico-occlusal  fillings,  as  adapted  to  and  completed  in  the  bicuspid. 

Fig.  232  is  a  transaxial  section  at  the  line  A  on  Fig.  231 ;  and  at  this 
point  the  anchorage  for  the  minor  class  is  seen  in  Fig.  232.  The  anchor- 
age can  and  should  be  made  strong  here  under  the  buccal  lobes  of  bicus- 
pids and  molars,  and  similarly  at  the  lingual  sides.  Above  the  anchorage, 
toward  the  occlusal  surface,  the  cavity  should  be  so  modified  as  to  come 
out  on  the  occlusal  surface,  as  shown  in  Fig,  233. 


Fig.  233. 


Fig.  234. 


Fig.  235. 


End  view,  showing  outline  of 
major  and  minor  cavity 
preparation. 


Section  showing  the  completed 
major  class  filling  on  bicus- 
pid. 


M,  2-grain  cube  of  gold,  show- 
ing relative  size  to  the  cav- 
ity in  which  it  rests. 


The  pluggers,  Nos.  115  and  116  or  117  and  118,  Fig.  265 — pairs  in 
two  sizes — are  invaluable  for  tacking  the  cohesive  gold  into  the  condensed 
soft  gold.  Much  of  this  part  of  the  work  must  be  done  by  hand  pressure ; 
and  it  is  important,  in  view  of  this  fact,  to  prepare  the  gold  in  narrow 
strips,  which  should  be  annealed  with  electric  heat  to  insure  the  strongest 
cohesion. 


272  UiiK  or  THE  matrix  in  fillisc  operatioss. 

In  the  filliiii;  »il"  this  i-hiss  of  cavities  the  matrix  .sliouhl  bi-  applied, 
aiul  soft  goUl  hroiight  up  to  the  anchorage  shown  in  Fig.  232.  At  this 
point  cohesive  gohl  shouUl  be  throughly  condensed  into  the  anchorages, 
and  brought  out,  finishing  the  contour  of  the  tooth.  Care  should  be 
taken  to  bevel  somewhat  the  occlusal  surface  of  this  filling  to  prevent  the 
too  positive  iiH[)inging  of  the  occluding  tooth  in  the  opposite  jaw. 

The  beginning  of  the  cohesive  on  the  condensed  soft  gold  and  the 
fastening  of  it  there,  in  whatever  class  of  cavities,  dejK'nds  on  careful 
attention  to  several  details:  First,  the  operator  must  so  conduct  his 
operation  as  to  control  the  saliva  perfectly,  keeping  his  work  dry.  Second, 
the  matrix  must  be  fixed  and  rigid  in  its  application.  Third,  the  pluggers 
should  be  kept  freshly  serrated,  and  of  such  forms  as  give  direct  entrance 
to  and  application  of  them  at  the  ])oint  on  the  work.  Fourth,  the  ser- 
rations should  be  clean  and  deep.  Fifth,  the  gold  should  be  clean  and 
freshly  annealed.  Any  t)f  the  forms  of  cohesive  gold  may  be  used, 
if  the  portions  carried  each  time  to  their  destination  are  small  clean, 
and  annealed.  Small  cohesive  gold  cylinders,  Nos,  }  and  ^,  are  easily 
used  for  this  work,  and  the  smaller  ones  should  not  only  be  employed 
to  begin  with,  when  this  form  is  used,  but  as  far  as  practicable  throughout. 
The  strips  or  ril)l)ons,  however,  of  cohesive  gold  when  freshly  annealed, 
and  witii  all  other  conditions  above  enumerated  complied  with,  give  best 
results.  The  ribl)on  is  taeked  or  pricked  into  the  .soft  gold  by  interdigita- 
tion,  and  the  union  made  with  this  or  any  preparation  of  cohesive  gold, 
while  not  strong,  is  enough  so,  to  enable  the  operator  to  reach  his  anchor- 
age points,  where  he  may  thoroughly  secure  the  work. 

In  making  matrix  fillings,  if  the  matrix  employed  is  of  the  band  or 
loop  variety  and  has  no  separating  feature,  in  order  to  secure  contour, 
and  to  have  the  fillings  finish  in  the  original  form  of  the  tooth,  the  teeth, 
if  two  are  together,  should  have  the  c-avities  previously  packed  with 
cotton,  long  enough  to  produce  mobility  of  the  teeth  so  that  they  may 
more  easily  yield  apart.  This  then  gives  opportunity  to  push  the  teeth 
apart  still  further,  especially  with  those  matrices  provided  ^vith  the 
separating  feature,  and  so  to  gain  room  in  which  to  shaj)e  the  matrix 
band  and  to  reproduce  the  contour  of  the  tooth. 

Preparation  of  Gold  for  Matrix  Work. 
In  the  soft-gold  part  of  matrix  work  the  form  of  the  gold  to  be  em- 
ployed is  im|X)rtant  to  be  understood.  Large  cylinders  and  cushions  in 
comparison  with  those  ordinarily  used  in  cavities  of  given  size  are  not 
only  more  safely  and  perfectly  adapted,  but  more  quickly  done.  This 
results  from  doubling  and  partly  compressing  the  cushions,  which,  being 
further  susceptible  of  compression,  are  still  large  enough  to  squeeze  in 
place  and  bind  as  they  are  compressed. 


PREPARATION  OF  GOLD  FOR  MATRIX   WORK.  273 

In  placing  cushions  into  the  bottom  of  large  cervico-occlusal  cavities 
of  molars  and  bicuspids  embraced  by  the  matrix,  it  is  important  to  start 
with  those  of  sufficient  size  and  density  to  bind  as  they  are  condensed, 
but  it  is  not  to  be  understood  that  the  first  such  piece  introduced  must  be 
fully  condensed  before  other  similar  pieces  are  added.  If  this  practice 
were  followed,  notwithstanding  the  fact  that  the  first  piece  introduced 
binds  as  it  is  condensed,  this  is  so  only  to  a  certain  point  of  the  conden- 
sation. Beyond  this  if  we  continue  it,  especially  to  that  density  which 
may  be  obtained  against  the  resistance  the  tooth  aifords,  it  loosens,  will 
tilt  and  rock,  and  is  worthless.  But  if  after  placing  in  one  cushion 
which  the  operator  learns  to  proportion  to  the  size  of  the  cavity,  and 
partially  condensing  it,  he  introduces  another  and  carries  the  condensation 
to  the  point  of  the  first,  and  still  another,  he  may  then  mallet  until  the 
mass  will  yield  no  more;  and  the  wall  thus  built  will  be  steady,  well 
adapted,  moisture  proof,  and,  therefore,  impervious  to  leaking  by  capillary 
force.  This  comes  of  the  fact  that  when  three  or  more  cushions  or 
cylinders  are  carried  down  as  described,  the  bearing  up  and  down  of  the 
axial  and  matrix  walls  is  sufficient  to  insure  binding  and  steadiness. 

In  the  illustration.  Fig.  223,  will  be  observed  at  K  a  gold  cushion 
entering  the  cavity  between  the  axial  wall  f  and  the  matrix  band  h. 

Fig.  236. 


Leaf  of  No.  -4  gold  foil,  twisted,  ready  for  formation  into  cushions. 

The  cushion  is  made  of  one-half  of  the  gold  twist  shown  at  Fig.  236, 
and  contains  two  grains  of  gold  by  weight.  This  cushion,  when  con- 
densed to  its  ultimate  density,  as  by  melting  and  hammering,  is  repre- 
sented in  cube  form  and  exact  size  at  m,  Fig.  235. 

A  No.  4  gold  cylinder,  one-fourth  of  an  inch  long,  contains  one  grain 
of  gold  bv  weio;ht,  and  when  this  is  condensed  into  cubic  form  it  is  one- 
half  the  bulk  of  the  cube  shown  at  M,  Fig.  235.  It  transpires  then  that 
the  large  loosely-made  cylinders  of  one  grain  weight  are  more  difficult 
of  satisfactory  adaptation  than  those  which  contain  the  two  or  more 
grains,  because  the  large  loose  ones  lack  the  bulk  and  substance  which  is 
necessary  to  cause  them  to  bind  and  lock  in  condensing. 

It  will  be  seen  further,  by  comparison  of  the  2-grain  cube  M,  Fig. 
235,  with  the  proportions  of  the  cavity  in  which  it  rests,  that  it  reaches 
hardly  half  across  the  cavity,  bucco-lingually,  and  that  if  this  cube  were 
elongated  so  as  to  reach  across  the  cavity,  its  bearing  against  the  axial 
wall  and  the  matrix  band  would  be  lowered  at  least  one-half,  and  there 
would  not  be  sufficient  bearing  up  and  down  these  walls  to  hold  the  gold 
fixedly  in  place.     This  then  demonstrates  the  difficulty  of  adapting  gold 

18 


274  USE  OF   THE  MATRIX  L\   FILL  I  SO    OPERATIONS. 

or  tin-loil  at  siii'li  jxtints  witli  cylindrrs  or  ciisliioiis  containiii*;  less  than 
enough  material  to  liind  and  lock  the  ina><  in  jdaic  in  the  process  of"con- 
densino;.  And  if  this  hi."  true,  as  is  illustrated  in  Fig.  2o"),  it  is  seen  that 
the  size  4  cylinder,  containing  only  one  grain,  would  he  still  more  difhcult 
to  control,  because  it  lacks  in  greater  degree  tiie  hulk  and  suh.-tance 
sufhcient  to  give  the  i)earing  up  and  down  the  walls  necessary  to  the 
binding  and  locking  in  the  process  of  condensing.  XeitluT  will  the 
cylinders  or  cushions  containing  two  grains  or  more  in  very  large  cavi- 
ties hear  complete  condensing,  bef(jre  adding  other  pieces  without  loosen- 
ing, for  the  reasons  already  given.  In  exceptionally  large  cavities  of  the 
major  class,  a  sheet  of  No.  4  foil  may  be  formed  into  a  single  cushion, 
and  introduced  to  advantage.  Such  a  cushion  containing  four  grains 
would  not  build  higher  than  is  necessary  to  bind,  even  if  it  were  formed 
into  a  rectangular  parallelopiped — two  cubes  side  by  side,  and  extending 
from  one  lateral  wall  to  the  other.  Fig.  235. 

The  successful  making  of  fillings  with  either  gold  or  tin  is  not  so 
much  a  question  of  securing  the  ultimate  density  of  these  materials,  as 
tiiat  of  securing  adaptation  of  them  to  the  walls  of  the  cavity  in  such 
manner  as  shall  prevent  leakage  beneath  the  filling.  This  result  may  be 
obtained  with  a  compression  or  condensation  of  much  less  density  than  is 
shown  in  the  melting  of  them,  or  as  is  obtainable  against  the  resistance 
which  the  tooth  offers. 

Formation  of  Cushions  from  Foil. 

The  cushion  of  either  gold  or  tin,  rather  than  the  cylinder,  is  a  better 
pre])aration  for  matrix  work,  even  when  it  is  made  from  cylinders 
compressed  or  doubled  upon  themselves,  because  the  cushion,  made  of 
fiiil,  while  soft  enough  to  be  adapted  to  the  irregularities  of  the  cavity, 
contains  from  twice  to  four  times  the  amount  of  material  which  the 
loose  cylinders  do,  and  because  of  this  fact,  in  connection  with  proper 
cavity  formation,  they  are  more  easily  secured  in  place. 

The  student  should  appreciate  the  fact  that  until  he  succeeds  in  laying 
the  foundation  of  .soft-gold  work  in  a  manner  to  j)revent  its  moving  or 
shifting  position  in  the  process  of  condensing,  he  will  have  failed  to 
secure  the  results  within  his  reach.  The  employment  of  the  cushion, 
therefore,  rather  than  the  cylinder,  is  nrged  as  the  best  means  to  this 
end. 

The  formation  of  cushions  fnmi  the  foil  is  as  follows:  Take  a  full 
leaf  of  No.  4  soft  gold-foil,  and  with  clean  hands  crimple  and  wrinkle 
it.  Straighten  this  out,  but  leave  the  sheet  nndulated,  when  it  should 
be  loosely  folded  three  to  four  times  upon  itself  and  loosely  twisted.  The 
twist  thus  made  should  l)e  cut  into  from  three  to  five  pieces,  Fig.  236, 
dejiending  on  the  size  of  the  cavity  to  be  filled.     The  large  cavitie.s, 


FINISHING   THE  FILLING.  275 

such  as  are  seen  in  the  approximal  surfaces  of  molars,  Figs.  221  and 
222,  will  take  a  cushion  made  from  the  longer  section  of  the  twist 
shown  in  Fig.  236,  which  may  represent  one-half  or  more  of  the  sheet 
of  No.  4  foil ;  while  cavities  of  the  proportions  shown  in  Fig.  231  will 
take  one-fourth  or  less.  Smaller  approximal  cavities  in  the  incisors  will 
take  from  one-fifth  to  one-third  of  a  half-sheet  prepared 
after  the  manner  of  Fig.  .236.  The  cushions  prepared 
after  these  suggestions,  when  used  for  the  large  cavities 
of  the  molars  and  bicuspids,  should  somewhat  resem- 
ble the  illustration  in  Fig.  237.  The  preparation  thus  cushion  formed  from 
made  is  more  desirable  than  the  cylinders  made  of  soft  236,^  or  from  par- 
foil,  because  it  is  more  easily  manipulated  and  with  ti^Hy  compressed 
better  results,  and  because  the  student  learning  to 
do  this  secures  to  himself  a  resource  which  enables  him  to  prepare  his 
cushions  for  all  sizes  of  cavities,  and  is  never  at  a  loss  for  what  is  wanted 
when  foil  is  to  be  had. 

But  when  this  class  of  work  is  to  be  done  with  tin-foil,  the  cylinders, 
compressed  or  doubled,  will  serve  best,  since  it  is  difficult  to  obtain  a  foil 
of  tin  light  enough  and  soft  enough  to  make  desirable  cushions. 

Tin-foil  in  cushions,  made  by  doubling  the  cylinders  upon  themselves 
for  the  foundation  portion  of  cervico-occlusal  fillings,  in  connection  with 
the  matrix,  works  even  more  kindly,  and  adapts  more  easily  than 
cushions  made  from  soft  gold-foil ;  and  if  its  use  here  is  not  forbidden 
by  electrolysis,  it  is  to  be  given  first  place  as  a  tooth  preserver,  especially 
at  the  cervical  margins,  and  as  a  non-conductor  of  the  thermal  changes 
to  the  pulp.  Tin-foil  and  soft  gold-foil  laid  together,  and  the  two  formed 
into  cushions  after  the  suggestions  already  made,  may  be  used  with  results 
quite  as  beneficial  for  preservation  of  the  margins  embraced  by  the  matrix 
as  when  gold  or  tin  alone  is  used,  with  the  advantage  of  avoiding  the 
danger  of  electrolysis  of  tin  under  gold. 

Finishing  the  Pilling. 

No  part  of  the  work  of  making  gold  fillings,  such  as  are  included  in 
the  major  class  particularly,  is  more  laborious  than  the  finishing  of  them. 
Yet  when  the  matrix  has  been  projDcrly  adapted  to  the  teeth,  the  finishing 
of  the  cohesive  gold  part  may  be  lessened  to  the  minimum. 

The  more  rapid  and  satisfactory  finishing  of  the  work  following  the 
use  of  the  matrix  is  no  small  part  of  the  advantage  of  this  device,  since 
the  matrix  gives  not  only  the  form  of  the  wall  which  it  embraces,  but 
more  than  any  other  method  yet  devised  saves  filling  material.  This 
comes  of  the  fact  that  when  it  is  properly  adjusted  the  cavity  is  converted 
into  a  mold  so  nearly  the  shape  of  the  filling  to  be,  that  when  it  has 
been  made  very  little  work  remains  to  be  done  in  polishing. 


27(>  USE  OF  THE  MATRIX   I\  FILIjyG    OPERATIONS. 

The  first  step  toward  polishiiij^  ufttT  rcinoviiii,^  the  nuitrix  is  to  go 
around  the  borders  of  the  soft-gold  portion  of  the  filliiii;  witli  ii  bhide 
huriiishor,  wliich  slioiihl  \w  kept  highly  poli.slud  and  clean.  In  this 
c)pt'ration  the  object  should  be  to  eonij)ress  as  nuu-h  as  possible  hv  hand- 
pressure  the  soft-gold  portion  that  may  have  bulged  under  the  nialleting. 
After  this  the  Rheiu  trimmers,  Xos.  31  and  32,  should  go  ttver  the 
borders,  and  should  be  held  so  that  the  blade  shall  rest  ecpially  on  the 
filling  and  the  adjacent  external  surface  of  the  tootli. 

At  this  point,  if  the  operation  is  between  molars  or  bicuspids,  the 
Perry  or  the  Ivory  separator  is  valuable,  and  should  be  placed  so  as  to 
have  the  beaks  impinge  above  the  margin  of  the  filling,  and  should  be 
made  to  open  the  teeth  only  enough  to  pass  in  the  thinnest  strips  and 
sandpaper  disks.  Care  and  skill  are  rcfpiired  in  the  handling  of  disks 
to  avoid  grinding  away  the  contour  of  the  filling,  but  the  disk  can  be 
so  held  as  to  prevent  this. 

The  author  finds,  in  removing  the  overhanging  corners  of  the  cohe- 
sive portion  of  these  fillings,  that  the  use  of  a  stili"  five-eighth  inch  garnet 
disk,  held  only  to  the  corners  and  not  permitted  to  jiass  in  between  the 
teeth,  answers  better  than  any  form  of  corundum  or  carborundum 
wheels. 

After  thus  carefully  shaping  the  caj)  or  slab  of  cohesive  gold  at  the 
contact  points,  and  rounding  them  as  the  case  permits  and  requires,  flint 
strips  and  the  "regular"  grit,  followed  with  the  "fine"  cuttlefish  disk, 
completes  the  polish. 

The  occlusal  surface  of  cohesive  gold  is  easily  shaped  with  corundum 
wheels  and  polished  with  the  cuttlefish  disk,  when  these  can  be  made  to 
apply,  or  with  leather  wheels  carrying  ])nmice. 

There  is  no  essential  difference  in  polishing  the  major  and  minor  class 
of  these  fillings,  except  in  the  extent  of  the  work. 

Forms  of  Matrices  for  Molars  and  Bicuspids. 

A  presentation  of  all  the  devices  known  as  matrices  is  not  the  purpose 
of  this  chapter,  but  only  of  those  whose  efficiency  commends  them. 

Fig.  238. 


ii 

The  matrices  of  Dr.  Lmiis  Jack. 


Fig,  238  represents  the  set  of  matrices  devised  by  Dr.  Louis  Jack. 
This  set  of  matrices  is  provided  with  concave  surfaces  for  contouring  the 


FORMS  OF  MATRICES  FOR  MOLARS  AND  BICUSPIDS. 


277 


teeth,  which  indicates  the  high  ideal  of  the  originator  of  the  device. 
They  are  made  thicker  and  heavy  at  the  base  of  the  lateral  edges,  which 
aids  in  steadying  them  between  the  teeth,  and  they  are  provided  with 
slotted  edges,  which  engages  a  special  pliers  to  insert  and  remove. 


Fig.  239. 


I^oop  matrices 


Fig.  239  shows  a  set  of  loop  matrices,  which  at  times,  and  with  teeth 
of  slight  constriction  at  the  neck,  answer  well,  but,  like  all  of  the  loop 
variety,  they  require  space  at  both  sides  of  the  tooth  to  admit  of  adjustment. 

Fig.  240. 


Brophy's  band  matrices. 

Fig.  240  exhibits  a  set  of  matrices  devised  by  Dr.  Truman  W.  Brophy, 
which,  with  the  flexibility  of  the  thin  steel  bands  and  under  the  action 
of  the  screw,  may  be  made  to  aid  the  operator  most  acceptably. 

The  band  is  not  unlike  the  loop  in  the  matter  of  passing  between  the 
teeth,  and  the  teeth  must  yield  apart  to  admit  it.  Still,  with  the  thinness 
of  the  bands  in  this  set,  there  is  no  difficuty  in  this  particular. 

This  form  of  matrix,  however,  is  unsteady  and  difficult  to  fix  rigidly 
on  very  short  crowns,  and  particularly  on  those  of  decided  conicality. 

Fig.  241  exhibits  an  improved  loop  matrix  devised  by  Dr.  S.  H. 
Guilford,  in  which  the  lip  feature  is  added  for  the  purpose  of  having  the 
band  to  catch  below  the  cavity,  without  the  necessity  of  forcing  the  band 
elsewhere  around  the  tooth  into  the  gum.     This  device,  made  in  several 


278 


U;SE  OF  THE  MATRIX   L\   FILLISd    OPERATIONS. 


IciuTtlis  <»f  bands,  altlioiigh   tedious   to  adjust   from  the   fact   tliat   throe 
pieces  must  be  handled,  is  otiierwise  vahiabK'  and  serviceable. 


Fig.  241. 


Guilford's  band  matrices  and  clamps. 


Fig.  242  illustrates  T)r.  W,  A.  Woodward's  screw  matrices.  This 
form  of  matrix  has  valuable  features  in  that  the  thin  metallic  ribbon 
constituting  the  matrix  wall  may  be  made  as  thin  as  No.  36  to  88  gautr(>, 
and  yet  possesses  ad(>qnate  tensile  strength.     The  device  is  also  valuable 


Fig.  242. 


because  in  its  use  only  one  thickness  of  the  ribbon  need  be  carried  be- 
tween the  teeth.  Again,  it  has  the  separating  feature,  which  makes  it 
additionally  desirable,  as  this  forces  apart  the  teeth  to  start  with,  and  the 
separation  is  continued  as  the  operation  proceeds,  or  as  the  exigency  of 
the  case  demands. 

To  Chapter  XIV.  in  this  volume,  on  Combination  Fillings,  by  Dr. 
Dwight  M.  Clapj),  the  student  is  referred  for  the  desc-ription  of  his  matrix 
devices  and  their  application.  These  matrices  are  quite  as  well  employed 
for  making  gold  and  the  plastic  fillings  as  for  the  specific  purpose  of 
combination  fillings. 

Fig.  243  shows  illustrations  of  Dr.  E.  R.  Lodge's  matrix  bands,  ten- 
sion screws,  and  wrench.     Those  marked  a  are  adapted  to  bicus})ids  and 


FORMS  OF  MATRICES  FOR  MOLARS  AND  BICUSPIDS. 


279 


molars  of  usual  form,  while  those  marked  b  are  adapted  to  the  same  class 
of  teeth,  but  of  constricted  necks  and  more  pronounced  bell-shaped 
crowns,  c  and  d  of  this  illustration  show  two  forms  of  tension  screws, 
and  F  and  e  the  wrench  for  operating  the  screw  D,  Fig.  244  shows  the 
Lodge  device  adiusted  to  the  teeth. 

Fig.  243. 


F  (^  ^^^mmmmf^miims  d 


Lodge's  system  of  loop  matrices. 

The  bands  of  the  Lodge  matrix  are  made  of  German  silver,  and  are 
provided  with  two  eyelets  in  each,  giving  ample  range  of  adjustment. 

Figs.  245  and  246  show  a  form  of  matrix  suggested  by  Dr.  A.  C. 
Hewett,  which,  for  simplicity  and  efl&ciency,  meets  a  constantly  occurring 
want.     In  the  instances  where  the  matrix  is  employed  between  the  teeth 

Fig.  244. 


and  it  is  braced  by  an  adjacent  tooth,  and  where  no  straining  apart  of  the 
teeth  is  required,  this  device  is  admissible.  But  it  should  be  braced  with 
a  wedge,  ordinarily  at  the  cervical  edge. 

Fig.  247  is  a  form  of  matrix  which  has  been  used  by  the  author  in 
extensive  cavities  occurring  on  the  buccal  surfaces  of  lower  molars. 


280 


vsE  OF  nil-:  .v.iv7;/.v  f.\  rnj.ixa  (/pkratioKs. 


Tlio  IkuuI  wliicli  must  Ik-  fitted  to  facli  case  is  iiuule  i'rom  No.  35  to 
36  ^auge  Gernum  silver,  ami  so  cut  that  the  projecting  arms  turned  down 
on  the  occlusal  surface  of  the  tooth  prevent  it  from  carrying  down  with 
the  wedge  as  the  device  is  tightened.  In  the  instances  where  the  cavity 
extends  beneath  the  gum  the  hand  can  be  provided  with  a  lip  to  catch 
below  the  buccal  margin.  The  dam  can  rarely  be  employed  in  these  opera- 
tions, but  fortunately  it  is  not  necessary  for  the  first  jiart  of  this  ojH-ration. 


Vn;.  1245. 


Fig.  240. 


Fjc;.  247. 


The  Hewett   matrix    held    in        The    Itewett    iniitrix   held  in    The  band  matrix  nsed  in 
position    with    the    I'armly  position   witli   the  ordinary        exlensive  buccal  surface 

Brown  clamp.  rubber-dam  clami).  cavities  on  lower  molars. 

When  the  lingual  and  buccal  sides  of  these  teeth  are  provided  Avith  ab- 
sorbent-cotton rolls,  and  especially  when  the  saliva  ejector  is  employed, 
the  cavity  can  easily  be  filled  to  the  top  of  the  band  with  soft  gold 
or  tin,  as  suggested  elsewhere  in  this  chapter,  before  moistu're  shall 
interfere. 

If  the  capping  for  this  filling  shall  be  of  amalgam,  it  can  be  finished 
within  the  time  the  alxsorbents  protect.  If  the  purjiose  is  to  finish  with 
gold,  the  dam  should  at  this  juncture  be  placed  over  the  band  and  tooth 
after  the  soft-gold  ])art  is  brought  to  the  top  of  the  band,  and  the  remain- 
der of  the  Avork  finished  with  cohesive  srold. 


Fiu.  248. 


Fifi.  249. 


The  Hodson  contoiir  slip  matrices. 


The  Hodson  matrix  in  jjosition  between  the 
teeth. 


Fig.  248  represents  the  contour  sli])  matrices  devised  by  Dr.  J.  F.  P. 
Hodson.  The  device  is  a  most  meritorious  one,  with  which  the  contour 
of  molars  and  bicusj^ids  can  be  fully  restored,  but  can  only  be  used 
between  the  teeth.  Fig.  248  gives  two  views  of  the  matrix  ready  to  be 
slipped  in  place. 

These  matrices  are  made  preferably  of  thin  annealed  steel  plate,  forged 
or  swaged  on  a  leaden  slab  with  an  oval-end  punch,  giving  them  what- 
ever of  concavity  the  case  mav  require,  they  are  then  slipped  in  place. 


FORMS  OF  MATRICES  FOR  MOLARS  AND  BICUSPIDS.         281 

which  causes  the  teeth  to  yield  apart.  The  gingival  end  of  the  device 
should  be  braced  against  the  adjacent  tooth  with  an  orange-wood  wedge 
until  after  the  filling  is  inserted. 

The  Hodson  device  is  better  adapted  to  amalgam  work  than  gold,  be- 
cause it  does  not  possess  the  rigid  fixedness  in  sufficient  degree  to  remain 
securely  in  place  for  extensive  gold  operations. 

If  the  filling  material  used  is  a  plastic  the  device  is  left  in  place  over 
night  or  longer,  allowing  the  filling  to  set  under  pressure,  which  may  be 
done  readily,  as  the  device  shown  in  Fig.  249  is  in  no  wise  uncomfortable 
or  troublesome  to  the  wearer. 

When  the  adjustment  of  the  matrix  is  properly  made,  it  is  unneces- 
sary in  most  instances,  particularly  in  the  uper  jaw,  to  use  the  dam. 

Fig.  250  represents  the  contour  matrix  as  devised  by  the  author  of 
this  chapter.  This  device,  which  is  of  duplex  form,  is  only  used  between 
the  teeth,  and  acts  in  the  three-fold  capacity  of  matrix,  separator,  and 
rubber-dam   clamp.      The   device   is   shown   in  position   between  two 

Fig.  250.  Fig.  251. 


The  Crenshaw  contour  matrix  in  position  The  contour  matrix  with  one  band 

between  molars.  turned  out  for  removal. 

molars,  the  cavities  of  which  have  been  prepared  after  the  suggestions 
of  Figs.  221,  222,  and  223,  and  the  manner  of  introducing  the  cushion. 
With  this  form  of  matrix  the  teeth  may  be  drawn  apart  as  with  the  sep- 
arator, and  the  fillings  given  the  contour  the  teeth  originally  possessed. 

Fig.  251  shows  the  method  of  removing  the  matrix,  as  may  be  done 
when  amalgam  is  used  without  lifting  or  unseating  the  filling.  To  do 
this  the  pin  is  withdrawn  and  the  band  embracing  the  unfilled  tooth  is 
turned  out  on  the  tension  screw  as  a  pivot.  After  this  the  band  embrac- 
ing the  filled  tooth  is  lifted  away  from  it,  when  the  matrix  may  be 
removed  from  between  the  teeth.  In  amalgam  work  with  this  device 
only  one  tooth  should  be  filled  at  a  sitting,  and  after  this  filling  has  crys- 
talized  and  become  fixed  in  the  tooth  the  second  one  should  be  made. 

Fig.  252  shows  how  the  operator  may  protect  his  work  without  the 
dam  in  the  lower  jaw  by  placing  absorbent-cotton  r'olls  on  each  side  of 
the  teeth,  and  how  these  are  held  in  place  by  the  matrix.     The  employ- 


282 


USE   OF   THE  MATRIX  IS  FILIJSU    OrEIiATIOyS. 


inent  of  tlu'  cotton  rolls  <j:;ivos  time  in  wliicli  to  insert  amalgam  and  other 
j)lastii'  tillintr^  ht'torc  the  rolls  l)oconu'satiiratf(l  with  saliva.  In  the  same 
manner  the  eervieo-oivlusal  eohinis  ol"  these  Hllings  may  he  made  of 
gold  or  tin  cushions  to  the  top  of  the  stej)  witii  the  aid  of  the  rolls  and 
the  saliva  ejector,  \vhen  the  matrix  should  he  removed,  the  dam  put  over 
the  teeth,  the  matrix  reapplied,  and  the  operation  finished  with  cohesive 

gold. 

Fk;.  1202.  Fig.  253. 


The  contour  matrix  holding  absorbent  cotton 
in  position. 


The  contour  matrix  in  position  between 
bicuspids. 


Fig.  25.3  shows  the  application  of  the  short-har  matrix  as  adapted  to 
hicusjnds  and  hetween  canines  and  fir.st  hicuspids.  The  hicuspid  device 
is  hetter  adapted  for  use  hetween  molar  and  hicuspid  than  the  molar  one, 
although  the  latter  may  be  employed  at  these  points. 


Fi(i.  2.-)4. 


Fig.  255. 


C  B 

The  contour  matrix  in  i>(iMuon  between  canine         Enlarged  figure  of  the  anterior  teeth  matrix 
and  first  bicuspid,  with  buw  brace  attached.  a  and  B,  arms;  c,  projection  screw  ;  d,  metal- 

lic ribbon. 

Fig.  254  shows  the  contour  matrix  in  position  between  a  canine  and 
first  bicuspid,  in  connection  with  the  bow  brace,  which  prevents  the 
matrix  slipping  from  between  the  teeth,  as  it  is  inclined  to  do  on  account 
of  the  bevel  of  the  lingual  side  of  the  canine. 


Matrix  for  the  Anterior  Teeth. 

In  the  effort  to  improve  gold  work  in  the  approximal  cavities  of  the 
anterior  teeth  bv  a  method  which  practically  does  away  with  cohesive 
gold,  the  author  offers  the  anterior  teeth  device. 

Fig.  255  shows  the  device  enlarged,  as  it  appears  before  being  placed 
in  position  about  the  teeth,  and  with  the  lower   part  shown  in  section. 


MATRIX  FOB   THE  ANTERIOR   TEETH. 


283 


The  arms  A  and  b  project  through  the  loops  formed  on  the  ends  of  the 
metallic  ribbon  d,  the  thickness  of  which  is  ^c^  of  an  inch,  and  which 
may  be  passed  between  teeth  of  rigid  contact.  The  parts  A  and  b  are 
separable,  and  when  the  tension  screw  c  is  turned  in,  the  arm  b  is 
extended,  which  puts  the  ribbon  D  under  tension. 


Fig.  256. 


Fig.  257. 


The  metallic  ribbon  in  position  before  crimp- 
ing. 

Fig.  258. 


The  metallic  ribbon  adapted  to  tooth  after 
crimping. 

Fig.  259. 


The  holder  applied  for  tensioning  the  ribbon.  The  holder  applied  for  taking  up  slack  in  the 

ribbon. 


Fig.  260. 


Fig.  261. 


Application  of  the  ribbon  pressing  the  left  cen- 
tral forward. 


Application  of  the  metallic  ribbon  between  the 
anterior  lower  teeth. 


Fig.  256  shows  a  lingual  view  of  four  incisors  with  the  matrix  ribbon 
in  position  before  it  has  been  adapted  at  the  iucisal  edge.  Fig.  257  shows 
the    ribbon    crimped    and    soldered,    which  Fig.  263. 

adapts  it  closely  to  the  tooth  at  the  incisal 
edge,  and  to  the  surface  of  the  tooth  beneath 
the  ribbon. 

Fig.  258  presents  a  labial  view  with  the 
device  in  position,  and  shows  how  cavities 

Fig.  262. 


Application  of  the  holder  pressing  the  lower 
right  central  forward. 


E,  cervical,  f,  incisal,  o,  lingual,  h,  labial 
subdivision  of  approximal  incisor  filling. 


which  extend  through  and  open  on  the  liugual  face  of  the  tooth  may  be 
floored  and  brought  into  simple  form. 

Fig.  259   shows  a  means  of  taking  up  slack  in  the  ribbon,  if  this 


284  USE  OF  THE  MATRIX  L\  EILLLSU    OPERATloSS. 

should  iK'Comeiioecs.sirv,  hytjlippiiiir  tlicslittcd  arm  astride  of  tlic  rihhoii, 
as  shown  in  this  ii<;inv.  Jiy  this  means,  if  at  any  time  the  tension  serew 
shonld  1)1'  i-iin  in  to  its  limit,  additional  tension  can  lie  nhtained  witiiont 
removini;  the  ribbon. 

Fig.  200  is  a  view  showing  the  eutting  edge  of  tlie  teeth  and  the 
crimp  of  the  metallic  ribbon. 

Fig.  2(51  is  an  ajjplication  of  the  ribbon  to  the  lower  incisors.  It  mnst 
ordinarily  be  placed  between  the  teeth  before  applying  the  holder.  Fig. 
262  shows  the  holder  iu  position. 


Filling  Approximal  Cavities  with  Cohesive  and  Non-cohe- 
sive Gold  with  the  Anterior  Teeth  Matrix. 

Fig.  26.3  shows  an  aj)proximal  cavity  in  a  central  incisor  three-fourths 
filled  by  the  aid  of  the  matrix,  after  which  the  matrix  is  removed.  The 
subdivisions  of  the  filling,  lettered  e,  f,  and  G,  are  made  of  soft  gold, 
leaving  the  space  marked  h  to  be  filled  with  cohesive  gold.  The  pro- 
cedure which  best  accomplishes  this  is  as  follows:  If  the  cavity  be  a  large 
one,  take  a  No.  3  or  4  soft-gold  cylinder  and  double  it  upon  itself  and 
again  crosswise,  making  a  firm  cushion.  Let  this  cushion  be  large 
enough  to  squeeze  into  place.  Take  a  foot-shaped  plugger  with  light 
serrations,  Nos.  257,  2.")8,  or  259,  Fig.  26o — whatever  size  of  this  form 
best  suits  the  case — and  ])ress  this  first  cushion  into  the  undercuts  of  the 
cavity  at  K.  After  settling  it  by  hand-pressure,  take  a  suitable  fijot- 
sliaped  j)lugger,  No.  257  or  258  answers  well,  in  the  automatic  mallet, 
and,  while  holding  down  at  the  lingual  side  of  the  cushioji,  mallet  the 
other,  after  which  change  the  instruments  about,  and  mallet  the  labial 
side.  After  this  is  done,  treat  the  opposite  end  of  the  cavity  at  f  in  the 
same  way,  only  the  cushion  going  into  this  subdivision  may  occasionally 
have  to  be  drawn  into  place  with  the  throat  of  the  instrument.  When 
the  F  subdivision  is  condensed,  use  a  No.  2  cylinder  folded  (jnce  upon 
itself,  and  introduce  end-wise  at  G,  which  when  condensed  keys  E  and  F 
in  place.  If  the  cavity  be  a  large  one  it  will  require  two  (»f  the  No.  2 
cylinders,  and  in  some  cases  three,  to  bring  this  part  of  the  filling  to  the 
centre  of  the  cavity,  which  is  necessary  in  order  to  securely  brace  e  and 
F  in  place. 

The  author  cautions  against  using  small  soft  cylinders  with  which  to 
make  the  key-block,  because  when  condensed  they  do  not  build  up  high 
enough  to  ol>tain  the  necessary  lateral  bearing  against  blocks  E  and  F  to 
hold  firmly  in  place.  Neither  should  cohesive  gold  in  any  form  be  used 
here. 

It  will  be  observed  from  the  lines  of  the  cavity  division  in  Fig.  263 
that  the  cavity  is  to  be  tilled  from   the  labial  side,  and  that  it  extends 


THE  HANDLES  ADAPTED   TO   THE  PLUGGERS.  285 

through  into  the  lingual  face  of  the  tooth,  also  that  the  matrix  ribbon, 
which  has  been  removed  to  show  the  plan  of  the  filling,  envelops  and 
embraces  the  tooth  in  such  manner  as  to  floor  the  lingual  portion  of  the 
cavity,  as  may  be  seen  in  Figs.  258,  259,  261,  and  262. 

The  action  of  the  device  not  only  moves  the  tooth  forward  to  be  filled 
as  seen  in  Fig.  260,  so  that  it  may  be  got  at  easily,  but  transforms  a  dif- 
ficult cavity  into  one  of  easy,  simple  form. 

In  the  instances  where  the  opening  of  the  cavity  is  toward  the  lingual 
aspect  with  a  labial  wall  to  be  preserved,  the  device  operates  with  as 
much  favor  in  filling  from  the  lingual  as  from  the  labial — see  Figs.  257 
and  260.  In  these  figures  the  action  of  the  device  will  be  seen  to  move 
forward  the  left  central,  and  depress  the  right  central  and  left  lateral. 

When  the  filling  is  made  from  the  lingual  aspect,  the  lines  of  the  sub- 
divisions of  the  filling,  Fig.  263,  would  be  reversed,  and  the  key-block 
would  be  placed  at  h,  with  H  occupying  the  position  of  g. 

Pluggers  for  Matrix  Work. 

The  point  of  a  plugger  is  not  all  of  its  efficiency.  The  handle  may 
materially  enhance  or  handicap  its  performance,  and  the  average  student, 
unless  guided  in  the  selection  of  points  and  handles,  is  apt  to  get  together 
in  the  selection  of  excavators  and  pluggers  an  incongruous  combination, 
much  of  which  will  prove  unsuited  and  unfitted  for  anything  he  is 
called  on  to  do. 

Some  of  the  forms  of  pluggers  here  suggested  for  matrix  work  may 
be  found  in  the  student's  case.  All  included  in  the  list  of  Fig.  265  are 
regarded  as  cohesive  gold  instruments,  but  several  of  these  forms  are  ill 
adapted  to  that  work  and  well  adapted  for  soft  gold.  Many  of  the  forms 
of  instruments  included  in  sets  of  soft-gold  pluggers  cannot  be  utilized 
in  the  execution  of  the  soft-gold  part  of  the  matrix  fillings  set  forth  in 
this  chapter ;  and  to  assist  the  student  in  knowing  which  instruments 
shall  be  used  to  manipulate  the  cohesive,  and  which  the  soft,  and  the 
handles  best  suited  to  them,  are  pointed  out  and  explanation  of  their 
uses  made.^ 

The  Handles  Adapted  to  the  Pluggers. 

Nos.  7,  8,  10,  18,  115,  116,  117,  118,  207,  and  208  should  be  placed 
in  cone-socket  handles  Nos.  4  or  5,  Fig.  264,  according  as  the  shank  of 
the  plugger  point  is  small  or  large.  These  handles  can  be  used  for  hand- 
pressure,  but  are  designed  especially  for  the  hand-mallet. 

Nos.  174,  175,  248,  and  250  should  be  placed  in  the  cone-socket 

^  The  handles,  pluggers,  and  numbers  of  same,  are  taken  from  the  revised  lists  of  the 
S.  S.  White  Dental  Manufacturing  Company. 


286 


USE   OF   THE  MATRIX   IN  FILLING    OPERATIONS. 


hamllcs  Nos.  2  or  .'>,  Fig.  204,  according  as  the  shank  of  the  plugger 
point  is  small  or  large. 


Fig.  204. 


3  4  5  10 

Handles  for  cone-socket  points. 


Nos.  257,  258,  and  259  should  be  placed  in  the  rubber  handles  No.  10 
or  10a,  Fig.  264,  according  as  the  shank  of  the  plugger  point  is  small 
or  large. 


THE   USES  OF  THE  SEVERAL  PLUGOEBS. 


287 


The  Uses  of  the  Several  Pluggees. 

Nos.  1,  8,  115,  116,  117,118,  and  207,  Fig  265,  are  for  cohesive 
gold,  and  may  be  made  to  answer  the  needs  of  this  work  in  conection 
with  matrix  fillings. 

No.  60  Parmly  Brown  plugger  point,  for  cohesive  gold,  is  of  uni- 
versal application,  and  is  best  used  in  the  electric  or  the  engine  mallet. 

Nos.  174  and  175,  Fig.  265,  are  assistant  pluggers,  used  to  hold  down 


Fig.  265. 


ills 


18     115  116   117  lis      174    175     207    208      218    250    257  258  259 
Condensed  set  of  pluggers. 

when  malleting ;  and  may  be  used  for  packing  cushions  in  the  cervico- 
occlusal  column  of  molar  and  bicuspid  matrix  fillings. 

Nos.  248  and  250,  Fig.  265,  are  for  soft  gold,  and  used  for  placing 
and  compressing  the  cushions  into  the  subdivisions  E  and  r.  Fig.  263, 
of  the  smaller  class  of  approximal  incisor  cavities. 

Nos.  257,  258,  and  259,  Fig.  265,  are  for  compressing  the  cushions 
into  the  subdivisions  e  and  r.  Fig.  263,  of  the  larger  class  of  approximal 
incisor  cavities.  The  square  corners  at  the  toe  of  these  forms  should  be 
rounded  off. 

Nos.  10,  18,  208,  248,  and  250,  Fig.  265,  are  for  settling  and  mal- 
leting soft-gold  cushions  in  the  cervico-occlusal  column  of  molars  and 
bicuspids,  see  Figs.  223,  226,  and  227,  and  for  carrying  down  and  mal- 
leting the  subdivision  g.  Fig.  263,  and  fillings  of  this  class. 

A  Matrix  Auxiliary. 

[Dr.  Alfred  P.  Lee,  of  Philadelphia,  has  devised  a  simple  and  practi- 
cal method  of  overcoming  the  difficulty  often  experienced  in  adapting 
the  matrix  to  an  approximo-occlusal  cavity  when  the  cervical  portion 
of  the  missing  wall  presents  a  concave  surface,  due  to  the  tendency  of 
the  roots  to  bifurcate. 

By  the  use  of  sheet  copper,  not  more  than  j-^^-^  of  an  inch  in  thick- 
ness, in  conjunction  with  the  Ivory  or  similar  matrix,  an  appliance  is 
made  which  when  removed  after  the  filling  has  been  inserted  will  be 


288 


USE  OF  THE  MATRIX  IX  FIIJAXd    OPERATIONS. 


found  to  Ikivc  kept  the  lilling  tlic  desired  shape,  leaving  no  overluinging 
portions  at  the  cervix  to  trim  away. 

A  pieee  of  th(»roiighly  anneah'd  eopper  phite,  hirgo  enough  to  cover 
the  ai)proxinial  portion  of  the  cavity  and  extend,  say  one-eighth  of  an 
inch  beyond  the  buccal  and  lingual  margins,  is  pressed  with  cotton  or 
bibulous  paper  pellets  to  conform  to  the  concave  root  ])eriphery  at 
the  cervix.  The  copper  is  then  carefully  removed  and,  if  the  cavity 
be  for  amalgam,  the  depression  in  the  copper 
representing  the  cervjcal  concavity  is  filled 
with  hard  wax  until  a  convexity  is  obtained ; 


Transverse  section  of  tooth  at     Both  matrices  in  position  on     Shows  copper  plate  with  cervi- 


a  point  near  cervical  border 
of  cavity.  Outer  line  show- 
ing copper  matrix  in  posi- 
tion. Dotted  line  represents 
degree  of  contour  supplied 
with  hard  wax  or  solder. 


tooth  crown. 


cal  depression  filled  with  soft 
solder  and  applied  to  cavity 
before  adjustment  of  outer 
matrix. 


the  copper  plate  is  then  placed  in  position,  and  around  it  a  steel  matrix 
is  adjusted,  and  when  fully  tightened  the  free  edge  of  the  copper  is 
burnished  against  the  steel. 

When  gold  is  to  be  inserted  it  is  necessary  to  use  something  more 
stable  than  the  hard  wax,  therefore  the  concave  surface  at  the  cervical 
margin  of  the  copper  plate  is  touched  with  zinc  chlorid,  and  over  the 
alcohol  or  Bunsen  flame  soft  solder  is  flowed  into  the  depression.  Any 
surplus  may  be  trimmed  off  with  a  disk. — Editor.] 


CHAPTER    XIII. 

PLA.STIC    FILLING    MATERIALS— THEIR  PROPERTIES,  USES, 
AND  MANIPULATION. 

By  Heney  H.  Burchaed,  M.  D.,  D.  D.  S. 


The  materials  included  in  the  heading  of  this  chapter  are — (1) 
Amalgam ;  (2)  Gutta-percha  and  its  preparations ;  (3)  The  basic  zinc 
cements. 

History. — The  introduction  of  the  first  member  of  the  group  was 
not  prompted  by  any  specific  merit  that  it  had  been  demonstrated  to 
possess,  but  was  due  solely  to  its  properties  of  easy  introduction,  com- 
paratively perfect  sealing  and  prompt  hardening,  qualities  which  appar- 
ently recommended  its  wide  and  general  use  to  those  not  possessing  the 
requisite  degree  of  skill  for  the  successful  manipulation  of  gold  foil. 

Applied  upon  a  basis  of  glaring  empiricism,  with  an  absence  of 
technical  skill,  the  material  received  the  prompt  and  sustained  con- 
demnation which  its  abuse  had  warranted.  The  steps  and  phases  of 
this  opposition  of  the  trained  and  skilled  against  untrained  and  un- 
skilled operators  may  be  read  in  the  dental  journals  of  from  1846  to 
1878  and  even  after.     It  was  commonly  known  as  the  "  amalgam  war." 

The  first  dental  amalgam  was  that  of  Taveau,  called  "  Silver  Paste." 
It  was  made  of  filings  of  coin  silver  (silver  9,  copper  1),  combined 
with  sufficient  mercury  to  make  a  plastic  mass.  It  was  presumably  this 
alloy  which  was  introduced  into  America  by  two  charlatans  named 
Crawcour,  under  the  glittering  title  of  "  Royal  Mineral  Succedaneum," 
The  discovery  of  the  nature  of  the  paste  followed  soon  after  its  intro- 
duction, which  was  clearly  prompted  by  the  motives  above  stated. 
Thereupon  followed  a  persistent  and  virulent  attack  upon  the  material 
and  all  who  used  it.  Upon  less  than  the  merest  shreds  of  evidence 
alleged  cases  of  salivation  and  mercurial  necrosis  were  recorded  as  due 
to  the  use  of  amalgam. 

That  amalgam  was  still  employed  by  the  practitioners  of  France  is 
evidenced  by  the  presentation  in  1849  of  a  formula  for  an  amalgam 
alloy  of  pure  tin  and  cadmium  by  Dr.  Thomas  Evans,  an  American 
dentist  practising  in  Paris.  An  amalgam  made  from  this  alloy  was 
found  to  shrink,  and  also  to  stain  the  dentin  of  teeth  into  which  it  had 
been  introduced,  owing  to  the  formation  of  cadmium  sulfid.     It  is  note- 

19  289 


200  PLASTIC  I'll. Lisa    MATERIALS. 

worthy  tliMt  Dr.  Kvans  liiinsc'll"  was  tlif  first  to  discover  and  make 
puhlic  tlic  deficiencies  of  his  amalgam. 

In  America  amalgam  remained  nnder  a  ban  nntil  T)r.  EHsha  Towns- 
end  of  Philadelphia,  a  practitioner  of  snch  great  skill  as  to  he  safe  from 
any  im[)ntation  of  lack  of  manipulative  ability,  introduced  in  1855  an 
alloy  of  44^  silver,  55^  tin.  The  amalgam  of  this  alloy  received  an 
endorsement  and  application  based  more  upon  the  eminence  of  its 
author  than  upon  the  results  of  actual  clinical  tests,  and  a  reaction 
occurred  which  brought  amalgam  again    under  general  coiidc  nination. 

What  was  known  as  the  "  new-departure  corps"  had  its  birth  shortly 
after  this  time.  This  was  composed  of  a  limited  number  of  practi- 
tioners and  metallurgists,  who  were  impressed  by  the  fact  that  gold  as  a 
filling  material  was  not  the  panacea  of  dental  caries,  and  that  by  inves- 
tigation alone  could  the  proper  place  of  amalgam  l)e  found  in  the  dental 
armamentarium.  It  is  due  to  this  group  of  investigators  to  state  that 
the  history  of  the  rational  employment  of  plastics  is  the  history  of  the 
"  new-departure  corps."  It  was  undoubtedly  due  to  it  that  plastics 
have  come  to  be  regarded  as  substances  having  definite  physical  and 
chemical  properties  which  fit  them  for  application  as  restorative  and 
therapeutic  agents  for  the  relief  of  clearly  defined  physical  and  patho- 
logical states.  As  the  properties  of  these  agents  become  better  under- 
stood, their  employment  more  closely  follows  what  is  known  as  rational 
therapeutics. 

The  use  of  any  or  of  all  of  these  several  materials  is  founded  so 
entirely  upon  their  individual  properties  that  a  discussion  of  these 
properties  must  precede  and  govern  that  of  their  methods  of  manipula- 
tion. 

Nature  and  Properties  of  Amalgam. 

An  amalgam  is  a  combination  of  one  or  move  metals  with  mereuri/  ;  it. 
is  therefore  any  alloy  into  which  mercury  enters  as  a  constituent.  The 
word  amalgam  (Fr.  anudgame)  is  derived  from  Gr.  aiia,  together,  yafxiw, 
I  marry  ;  or  from  S.na  and  /m/.ayna,  from  iialdaaco,  I  soften — because 
of  the  softness  and  fusibility  which  mercury  confers  upon  alloys. 

It  is  to  be  understood  that  amalgams  are  classified  as  alloys,  and  may 
be  therefore  members  of  any  of  Matthiessen's  groups  as  follows :  A  chemi- 
cal compound  in  which  the  affinities  are  exactly  satisfied  ;  one  in  which 
there  is  unstable  chemical  equilibrium  ;  a  sub-chemical  compound,  or 
a  mechanical  mixture — although  this  latter  is  rare,  as  mercurv  exhibits 
some  degree  of  affinity  for  all  metais. 

There  are  two  possible  ways  in  which  mercury  brings  about  the 
soluti<in  of  other  metals  :  First,  by  a  chemical  affinity  for  the  metals  ; 
second,  by  lowering  the   melting-point  of  the  solid  metal,   forming  an 


■^r*^^— 


NATURE  AND  PROPERTIES   OF  AMALGAM.  291 

alloy  whose  melting-point  is  higher  than  that  of  a  mean  of  its  constitu- 
ents. The  former  is  the  explanation  more  in  accord  with  the  observed 
phenomena  relative  to  the  combination. 

Physical  Properties  of  Amalgams. — As  a  class  amalgams  have  defi- 
nite physical  properties.  First,  that  of  hardening  from  a  previous 
plastic  condition ;  and  nearly  all  of  them  for  some  time  subsequent  to 
apparent  hardening  undergo  change  of  volume  and  of  form.  The 
change  of  volume  may  be  either  contraction  or  expansion. 

Contraction  and  Expansion. — In  contraction  the  mass  tends  to 
assume  the  form  shown  in  Fig.   266. 

It  has  been  shown  by  Dr.  Black  ^  that  Fig.  266. 

the  extent  of  this  contraction  is  due  to      « "^ 
several  factors  : 

1.  To  the  composition  of  the  pri- 
mary  alloy.  All  other  things  being 
equal,  an  alloy  of  65  per  cent,  silver, 
35  per  cent,  tin,  represents  about  the 
fixed  point  where  there  is  a  minimum  _.  ^       ^        ,   ■  , 

^  Diagram  of  amalgam  shrinkage. 

of  shrinkage.     As  a  class,  alloys  con- 
taining less  than  65  per  cent,  silver  make  amalgams  which  contract ; 
those    containing    more   than    65    per    cent,    silver   make    expanding 
amalgams. 

2.  To  the  amount  of  mercury  used  in  amalgamation.  There  appears  to 
be  a  definite  percentage  of  mercury  which  produces  the  greatest  strength 
of  an  amalgam  mass ;  moreover,  the  percentage  which  produces  the 
maximum  strength  increases  the  shrinkage  of  the  shrinking  alloys  and 
increases  the  expansion  of  the  expanding  alloys.  Surplus  mercury  in 
the  amalgam  mass  can  reduce  neither  the  expansion  nor  contraction 
of  the  amalgam  mass.  While  an  excess  or  deficiency  of  mercury  in- 
creases the  shrinkage  or  expansion  of  an  amalgam  (according  as  the 
percentage  of  silver  is  65  —  or  65  +),  these  volume  changes  cannot  be 
overcome  by  the  percentage  of  mercury.  An  excess  or  deficiency  of 
mercury  weakens  an  amalgam.  It  would  appear  that  the  conditions 
which  bring  about  the  most  perfect  union  of  the  metals  produce  the 
greatest  changes  of  bulk  in  those  alloys  in  which  changes  of  bulk  occur. 
An  alloy  the  amalgam  of  which  neither  shrinks  nor  expands  cannot  be 
made  to  do  so  by  changes  in  the  amount  of  mercury  employed. 

3.  A  strong  controlling  factor  has  been  found  to  be  the  evenness 
of  distribution  of  mercury  and  alloy  throughout  the  amalgam  mass. 
An  increase  of  the  ratio  of  silver  above  70  per  cent,  is  followed  by  an 
enormous  expansion  of  the  hardening  mass.  It  had  always  been  noted 
that  the  amalgam  made  of  a  coin-silver  alloy  bulged  from  the  walls  of 

^  Dental  Cosmos,  1895,  vol.  xxvii.  p.  637. 


292  I'l.ASTH'  I'll. use,    MATERIALS. 

a  cax  ity  iiiclosiiiti-  it.  Tliis  alloy  (-(Mitaiiis,  as  stated,  !)()  pel-  cent,  of  sil- 
ver. 'J'lie  a])))earaiiee  <»i"  an  expanded  anialuani  is  siniilai-  to  that  of  ice 
at  the  month  of  an  iron  tnhe  in  which  the  water  has  heen  fro/en. 

Co})} >er  amalgam  is  the  only  alloy  test<'d  by  Dr.  l^lack  which  nnder- 
went  no  change  of  form  in  hai'dening. 

"  Flow  "  OF  Amalcjam. — A  projuTty  attrihnted  to  certain  amalgam-s, 
that  of  spheroiding,  has  been  shown  by  Dr.  Black  to  be  without  exist- 
ence. The  bulging  of  amalgams  from  the  orifices  of  cavities  was  held 
to  be  due  to  tlu'  tendency  of  the  mass  to  assume  a  spheroidal  form,  hence 
the  term  spheroiding.  Tests  showed  the  appearance  to  be  delusive,  the 
phenomenon  being  due  to  expansion  and  not  to  a  s})heroidal  tendency. 
In  addition  to  the  properties  of  contraction  and  expansion  the  same 
investigator  has  discovered  the  property,  hitherto  unsuspected  in  amal- 
gams, that  of  flow.  The  j)roperty  of  flow — /.  e.  change  of  mass  form,  from 
molecular  motion  under  stress— had  been  observed  in  the  majority  of 
metals,  but  as  found  in  amalgams  it  has  a  unique  expression.  Instead 
of  being  limited  to  a  definite  degree,  proixM-tioned  by  the  stress  applied, 
it  has  been  found  that  amalgams  yield  repeatedly  to  the  same  amount  of 
stress  when  a])plie(l  at  intervals,  as  in  mastication,  or  yield  contimiously 
when  the  stress  is  constant.  The  process  appears  to  be  without  limita- 
tions. It  is  at  zero  in  copper  amalgams  ;  next  less  in  amount  with  alloys 
containing  55-60  per  cent,  of  silver  with  5  per  cent,  copper  and  the 
remainder  tin.  It  will  be  readily  seen  that  this  property  exercises  a 
great  influence  upon  the  integrity  and  adaptation  of  an  amalgam  filling. 

The  notes  quoted  from  Dr.  Black  were  compiled  from  studies  made 
of  amalgams  whose  exact  chemical  composition  had  not  been  actually 
tested  by  the  investigator.  Later  experiments '  made  with  alloys  pre- 
pared with  the  utmost  care  and  exactitude  by  the  investigator  himself, 
gave  widely  different  results  (particularly  as  to  the  effect  of  adding  a 
third  or  fourth  metal  to  the  basal  alloy)  in  the  direction  of  both  flow 
and  shrinkage.  The  first  series  of  experiments  which  appeared  to  show 
an  enormous  increase  of  shrinkage  and  flow  together  with  a  lessening  of 
edge  strength,  by  the  addition  of  a  third  or  fourth  metal  (except  copper, 
which  the  latest  experiments  still  show  to  lessen  flow  and  increase 
rigidity)  were  not  confirmed  when  Dr.  Black  experimented  w'ith  alloys 
made  by  himself,  and  an  additional  and  unsuspected  factor  was  taken 
into  consideration,  viz.  the  influence  of  heat  upon  the  alloy. 

It  has  been  noted  by  Dr.  J.  Foster  Flagg  ^  that  alloys  which  were 
freshly  cut  possessed  working  properties  different  from  the  same  alloys 
when  "  old  cut,"  or  when  aged.  Dr.  Black's  observations  appeared 
to  confirm  this,  and  his  later  experiments  were  directed  toward  deter- 
mining the  cause  underlying  the  change.     Motion,  which  was  said  to 

'  Dental  Cosmos,  December,  1896.  ■■*  Pla^itics  and  Plastic  Fillings. 


NATURE  AND  PROPEBTIES  OF  AMALGAM. 


293 


bring  about  the  change,  was  found  .to  have  no  influence.  After  exhaus- 
tive and  conclusive  experiments  it  was  ascertained  that  the  change  was 
due  to  a  molecular  alteration  of  the  cut  alloy,  through  a  process  of  an- 
nealing or  "  tempering  " — i.  e.  heat  was  the  agent  producing  the  change. 
The  degrees  of  heat  applied  ranged  from  130°  to  212°  F. 

It  was  found  that  the  amount  of  time  during  which  an  alloy  was 
subjected  to  the  action  of  heat  governed  the  extent  of  tempering ;  for 
example,  alloy  subjected  to  a  temperature  of  130°  for  a  given  period, 
had  the  amount  of  amalgam  expansion  reduced  a  given  amount ;  if 
the  heat  were  maintained  for  a  longer  period  the  expansion  was  corre- 
spondingly decreased.  Each  formula  has  its  zero  point  beyond  which 
tempering  has  no  effect. 

In  general  terms,  it  was  found  that  alloys  in  amalgams  which 
expanded  in  hardening  had  the  extent  of  expansion  reduced  by  anneal- 
ing ;  those  which  contracted  had  the  contraction  increased. 

Alloys  which  were  without  alteration  of  volume  unannealed,  shrank 
when  annealed. 

The  following  tables  will  show  the  extent  of  change  produced  by 
annealing.  It  will  be  noted  that  the  alloy  of  72.5  silver,  27.5  tin,  ex- 
hibits the  minimum  contraction  after  annealing.  It  will  also  be  observed 
that  less  mercury  is  required  to  effect  amalgamation  in  the  annealed 
alloy .^  Amalgams  made  from  annealed  alloys  have  both  their  flow  and 
crushing  stress  slightly  increased. 


I.  Exhibit  of  Unmodified  Silver- Tin  Alloys: 


FOBMnT.s".. 

How  prepared. 

Per  cent,  of 
mercury. 

Shrinkage. 

Expansion. 

Flow. 

Crushing 

stress. 

Silver. 

Tin. 

40 

60 

Fresh-cut. 

45.78 

6 

7 

40.15 

178 

40 

60 

Annealed. 

34.14 

9 

3 

44.60 

186 

45 

55 

Fresh-cut. 

49.52 

4 

8 

25.46 

188 

45 

55 

Annealed. 

32.13 

11 

1 

28.57 

222 

50 

50 

Fresh-cut. 

51.18 

2 

2 

22.16 

232 

60 

50 

Annealed. 

37.58 

17 

1 

21.03 

245 

55 

45 

Fresh-cut. 

51.62 

2 

2 

19.66 

245 

55 

45 

Annealed. 

40.11 

18 

0 

17.53 

276 

60 

40 

Fresh-cut. 

52.00 

1 

0 

9.06 

239 

60 

40 

Annealed. 

39.80 

17 

0 

14.10 

297 

65 

35 

Fresh-cut. 

52.00 

0 

1 

3.67 

290 

65 

35 

Annealed. 

33.00 

10 

0 

5.00 

335 

70 

30 

Fresh-cut. 

55.00 

0 

14 

3.45 

316 

70 

30 

Annealed. 

40.00 

7 

0 

4.67 

375 

72.5 

27.5 

Fresh-cut. 

55.00 

0 

42 

3.92 

275 

72.5 

27.5 

Annealed. 

45.00 

3 

0 

3.76 

362 

75 

25 

Fresh -cut. 

55.00 

0 

60 

5.64 

258 

75 

25 

Annealed. 

50.00 

0 

6 

5.40 

300 

^For  a  full  exhibit  of  this  stupendous  work  of  Dr.   Black's,  the  reader  is  referred 
to  his  contributions  in  the  Dental  Cosmos  for  1895  and  1896. 
2  Black,  Dental  Cosmos,  1896,  p.  982. 


2D4 


PLASTIC  FILIJMi   MATERIALS. 


II.   lu-hihit  of  Modified  SUrcr-Tin  Alloys} 


Formula.  ' 

": 

How  pre- 
pared. 
Tin. 

Per  cent, 
ofmercury. 

Crushing 
stress. 

Modifjing 
meUl. 

Silver. 

Shrinkage. 

Expansion. 

Flow. 

65 

35 

Fresh-cut. 

52.33 

0 

1 

3.67 

290 

65 

35 

Annealed. 

33.00 

10 

0 

5.00 

335 

66.75 

33.25 

Fresh-cut. 

51.52 

0 

4 

3.35 

329 

66.75 

33.25 

Annealed. 

33.53 

7 

0 

5.06 

380 

Gold  5. 

61.75 

33.25 

Fresh -cut. 

47.56 

0 

1 

4.62 

330 

Gold  0. 

61.75 

33.25 

Annealed. 

30.35 

7 

0 

6.07 

395 

Platinum  ^^. 

61.75 

33.25 

Fresh-cut. 

51.87 

0 

9 

9.68 

273 

Platinum  o. 

61.75 

33.25 

Annealed. 

37.33 

7 

0 

8.20 

352 

(opper  5. 

61.75 

33.25 

Fresh-cut. 

53.65 

0 

23 

2.38 

343 

Copper  5. 

61.75 

33.25 

Annealed. 

35.60 

5 

0 

3.50 

416 

Zinc  5. 

61.75 

33.25  Fresh -cut. 

56.65 

0 

68 

1.83 

290 

Zinc  5. 

61.75 

33.25 

Annealed. 

40.65 

0 

9 

2.07 

345 

Bismuth  5. 

61.75 

33.25 

Fresh-cut. 

46.26 

0 

0 

4.78 

288 

Bismuth  "). 

61.75 

33.25 

Annealed. 

23.67 

6 

0 

5.58 

308 

Cadmium  5. 

61.75 

33.25 

Fresh-cut. 

57.57 

0 

100 

6.40 

225 

Cadmium  5. 

61.75 

33.25 

.\nnealed. 

47.25 

0 

5 

3.54 

290 

Lead  5. 

61.75 

33.25 

Fresh-cut. 

44.17 

0 

1 

4.88 

290 

Lead  5. 

61.75 

33.25 

.\nnealed. 

32.76 

10 

0 

7.18 

276 

Aluminum  5. 

61.75 

33.25 

Fresh-cut. 

65.00 

0 

445 

Aluminum  1. 

64.5 

34.5 

Fresh-cut. 

46.98 

0 

166 

12.60 

198 

Aluminum  1. 

64.5 

34.5 

Annealed. 

38.26 

0 

48 

17.90 

213 

Edge  Strength. — What  is  termed  the  edge  .strength  of  an  amal- 
gam is  the  degree  of  resistance  an  edge  or  angle  of  an  amalgam  mass 
oflfers  to  force  which  tends  to  fracture  it. 

Amalgam."^  have  heretofore  been  regarded  as  rigid  crystalline  masses, 
utterly  devoid  of  malleability.  The  discovery  of  the  existence  of  flow 
at  once  modifies  all  previous  conceptions  and  data  regarding  edge 
strength,  for  it  is  evident  that  a  corner  or  angle  might  not  fracture  and 
yet  might  flow  under  the  stress  of  the  impact  of  mastication,  whereupon 
edge  strength  might  be  said  to  be  great,  and  in  reality  be  but  slight. 
In  view  of  the  existence  of  the  property  of  flow,  edge  strength  must  be 
measured  as  rigidity,  the  antithesis  of  flow,  and  a  high  crushing  stress. 

It  has  been  shown  that  contraction  or  expansion,  and  flow,  are  the 
influences  which  would  disturb  the  maintenance  of  size  and  forai  of 
an  amalgam  filling  ;  therefore,  a  minimum  of  shrinkage  and  flow  are 
the  primary  considerations  in  a  .'satisfactory  dental  amalgam, 

CoiX)R. — One  of  the  serious  drawbacks  to  the  wide  enij)loyment  of 
amalgam  has  been  its  objectionable  color,  both  in  its  original  state  and 
furthermore  when  it  has  suffered  discoloration  through  the  formation  of 
oxids  or  sulflds  upon  its  surface.  The  silvery  white  of  amalgam  in  its 
most  acceptal)le  condition  is  not  so  harmonious  a  color  as  the  vellow  of 
gold,  wliich  fact  has  led  first  to  the  restriction  of  the  u.se  of  amalgams 
to  such  spaces  as  are  not  readily  visible,  where  its  original  and  subse- 
quently its  altered  color  could  not  be  a  .strong  objection  ;  and,  next, 
'  Black,   hentd.  Cosmos,  1896,  p.  987. 


NATURE  AND  PROPERTIES  OF  AMALGAM. 


295 


has  prompted  a  modification  of  the  silver-tin  formulae  with  the  object 
of  maintaining  their  original  color. 

The  discolorations  are  not  alone  upon  the  external  surfaces  of  fill- 
ings, but  frequently  (and  most  frequently  in  improperly  prepared  and 
filled  cavities)  the  discoloration  affects  the  dentinal  walls  bounding  the 
cavity  (see  Fig.  167). 

Fig.  267. 


staining  of  tooth  structure  with  amalgam  (Bodecker) :  e,  enamel ;  D,  d,  dentin ;  B,  border  of  cav- 
ity; s,  solidified  dentin  along  the  border  of  the  cavity;  r,  reticulum  brought  forth  by  the 
amalgam.  (X  500.) 

As  shown  in  the  illustration  the  discoloration  may  be  deep.  This 
danger  is  increased  by  leakage,  when  putrefaction  of  the  protoplasmic 
contents  of  the  dentinal  tubuli  or  decomposing  albuminous  substances 
generate    H2S,  and  metallic  sulfids  are  formed  in  marked  quantities. 


206  PLASTIC  FILLING  MATERIALS. 

This  danger  of  dentinal  discoloration  is  gnardod  againirt  by  interposing 
a  barrier  between  the  cavity  walls  and  the  amalgam  prior  to  the  inser- 
tion of  the  latter.  The  inflncnoe  of  individual  metals  upon  color  will 
be  discussed  later. 

Thermal  and  Chemical  Relations. — As  a  conductor  of  thermal  in- 
fluence, amalgam  is  midway  between  gold  and  the  basic  zinc  cements. 

As  to  the  actual  effects  upon  the  vital  tissues  of  dentin,  it  has 
never  been  demonstrated  that  amalgam  exercises  any  specific  influence, 
except  that  cadmium  appears  to  cause,  through  the  cadmium  sulfid 
formed,  a  degenerative  influence  (Flagg),  and  copper  has  antiseptic 
properties  (Miller,  Fletcher). 

Chemically  the  dental  amalgams  arc,  to  all  intents  and  purposes, 
insoluble  in  the  fluids  of  the  mouth,  the  common  solvent  found  in  the 
oral  cavity,  lactic  acid,  affecting  them  but  little. 

Classification  of  Amalg-ams. — Amalgams  are  divided  into  binary, 
ternary,  quaternary,  and  so  on,  according  to  the  number  of  constituent 
metals.  The  only  binary  amalgams  employed  in  dentistry  are  those  of 
copper  and  of  palladium. 

Binary  Amalgams. — Copper  amalgam  is  made  by  adding  freshly 
precipitated  and  washed  metallic  copper  to  an  excess  of  mercury  ;  when 
solution  is  complete  the  surplus  mercury  is  expressed  through  chamois. 
The  plastic  residuum  is  then  packed  into  moulds  to  make  small  tablets 
of  the  usual  form  in  which  it  is  dispensed. 

A  better  method,  which  yields  a  product  of  greater  purity,  is  to  pre- 
cipitate the  copper  directly  into  the  mercury  by  electrolytic  process. 
This  may  be  done  conveniently  by  pouring  a  tjuantity  of  mercury  into 
a  suitable  glass  vessel — a  small  battery  jar,  for  example — and  suspend- 
ing a  thick  plate  of  copper,  by  means  of  a  wooden  support,  some  dis- 
tance above  the  surface  of  the  mercury.  A  saturated  solution  of 
cupric  sulfate  is  then  poured  into  the  jar  until  the  copper  plate  is  com- 
pletely submerged.  The  cathode  pole  of  a  battery  or  other  source  of 
electrical  current  is  then  connected  with  the  layer  of  mercury,  and  the 
anode  with  the  copper  plate.  All  that  portion  of  the  cathode  electrode 
in  contact  with  the  cupric  sulfate  solution  should  be  insulated  with  gutta- 
percha, and  only  the  point  which  is  in  contact  with  the  mercury  left 
exposed.  The  passage  of  the  current  causes  solution  of  the  copper 
from  the  anode  and  deposits  it  in  the  mercury  continuously  as  long  as 
the  foregoing  conditions  are  maintained.  The  precipitation  should  be 
continued  until  the  mercury  is  saturated,  which  will  be  evidenced  by 
the  appearance  of  the  characteristic  red  color  of  the  excess  of  copper  at 
the  cathode  pole.  When  the  saturation  point  has  been  fidly  reached 
the  mass  should  be  washed,  first  in  dilute  hydrochloric  acid  and  then  in 
water,  dried  and  compressed  as  is  usual  with  this  amalgam  when  pre- 


NATURE  AND  PROPERTIES  OF  AMALGAM.  297 

pared  by  the  ordinary  processes.  This  method  was  suggested  to  the 
writer  by  Dr.  E.  C.  Kirk. 

In  its  typical  form  and  condition,  copper  amalgam,  when  made 
plastic  by  heat,  may  be  packed  into  matrices,  such  as  cavities  in 
teeth,  where  it  sets  quickly,  undergoes  no  change  of  volume  or  form, 
and  is  devoid  of  flow.  Therefore  a  cavity  which  has  been  sealed  by 
it  remains  sealed.  Upon  its  outer  surface  a  coating  of  black  sulfid 
quickly  forms,  which  remains  but  does  not  penetrate  the  tooth  struc- 
ture. The  dentinal  walls  are  commonly  stained  green  through  the 
absorption  of  the  metallic  salts. 

In  improperly  prepared  specimens  there  is  not  a  perfect  chemical 
union  between  the  metallic  mercury  and  the  copper.  The  presence  in  a 
filling  mass  of  oxids  of  either  of  these  metals  establishes  local  electrolytic 
conditions  which  prevent  the  formation  of  the  black  sulfid  coating  and 
bring  about  the  gradual  dissolution  of  the  amalgam  mass.  To  recapitu- 
late :  Copper  amalgam  is  physically  unchangeable  as  a  filling  material ; 
it  brings  about  very  oiFensive  discoloration  both  of  the  dentin  and  of 
its  own  surface  ;  it  is  antiseptic. 

The  second  binary  amalgam  is  that  of  palladium.  Palladium  is 
precipitated  from  a  solution  of  its  chlorid  by  iron  or  zinc,  washed  in 
nitric  acid,  and  dried.  To  the  precipitated  metal,  mercury  is  added, 
the  combination  being  attended  by  the  evolution  of  much  heat  (i.  e.  is 
an  active  chemical  union).  If  an  excess  of  mercury  has  not  been  used 
the  amalgam  sets  quickly,  does  not  alter  in  form,^  and  becomes  black 
upon  the  surface,'^  but  does  not  discolor  the  dentin.  The  addition  of 
an  excess  of  mercury  retards  the  setting,  and  produces  an  inferior  filling. 

Ternary  Amalgams. — The  base  of  all  ternary  amalgams  is  the 
alloy  of  silver  and  tin.  The  first  of  these  was  the  alloy  of  Townsend, 
44^  per  cent,  silver,  55^  per  cent.  tin.  From  this  point  the  investi- 
gations and  experiments  radiated — it  being  found  after  many  years  of 
clinical  testing  that  those  alloys  containing  more  than  50  per  cent,  of 
silver  gave  the  best  results. 

The  formula  given  by  Dr.  J.  Foster  Flagg  as  affording  the  most 
stable  alloy  for  amalgam — 60  silver,  35  tin,  and  5  copper — was  found 
by  Dr.  Black  to  be  that  giving  the  highest  degrees  of  resistance  to 
change  of  form,  to  flow,  and  to  crushing.  In  view  of  Dr.  Black's 
researches  into  the  effects  of  annealing  alloys  it  is  evident  that  the 
ternary  amalgam  of  the  future  will  have  a  composition  closely  approxi- 
mating 72.5  per  cent,  silver,  27.5  per  cent.  tin. 

The  binary  alloys  of  tin  and  silver  form  the  basis  of  all  of  the 
quaternary  amalgams  used  in  dentistry. 

^  Tomes,  Trans.  Odontological  Society  of  Great  Britain,  1872. 
^  Bogue,  Dental  Cosmos,  1884. 


298  PLASTIC  FILLING   MATERIALS. 

Quaternary  Amalgams. — The  nu'tal  aiKlitioiial  t<»  the  l)asal  alloy 
is  added  for  the  purpose  of  modifying  the  cohjr  or  iiu'reasin<>:  the  edge 
strength  of  the  amalgam.  The  addition  of  eopper  o  jx-r  cent,  to  an 
alloy  containing  over  60  per  eent.  silver  increases  the  crushing  stress 
and  lessens  both  flow  and  contraction.  The  alloy  is  white  when  fresh, 
but  in  the  presence  of  sulfur  compounds  discolors. 

The  addition  of  gold  (o  ])er  cent.),  as  clinical  records  testify,  aids  in 
maintaining  the  color  of  the  tilling.  It  lessens  shrinkage  slightly  (com- 
])are  this  and  following  statements  with  tal)le  No.  II.),  and  appears  to 
have  little  or  no  influence  upon  flow  and  crushing  stress.  The  addition 
of  platinum  causes  dark  fillings  and  notably  increases  the  flow;  the 
setting  is  slowed. 

The  addition  of  zinc  increases  rigidity  ;  the  amalgams  expand  for 
long  ]ieriods  after  apparent  hardening ;  the  crushing  stress  is  moderately 
high — a  direct  contradiction  of  statements  of  several  previous  ob- 
servers.' 

Additions  of  bismuth,  cadmium,  lead  and  aluminum  were  made  to 
the  basal  alloy,  but  all  of  them  exhibited  properties  which  exclude 
them  from  introduction  into  dental  amalgam. 

Dr.  Black  ^  states  that  "  alloys  containing  5  per  cent,  of  aluminum 
have  their  setting  attended  by  the  evolution  of  nuich  heat ;  an  enormous 
expansion  of  the  mass  occurs  ;  the  instruments  used  in  packing  are  oxi- 
dized, and  a  distinct  crackling  of  gas-disengagement  is  heard."  "  The 
formation  of  aluminum  amalgam  is  characterized  by  an  exhibition  of 
the  affinity  of  aluminum  for  oxygen.  Aluminuin  oxid  is  doul)tless 
formed,  which  increases  the  volimie  of  the  amalgam  mass." 

"Washing  of  Amalgams. — Alloys  which  have  been  cut  for  some 
time,  and  mercury  the  purity  of  which  is  questionable,  are  found  to  be 
coated  with  oxids  of  the  metals — in  the  case  of  mercury,  with  the  oxids 
of  contaminating  metals.  The  advisability  of  washing  the  amalgam 
mass  in  some  solvent  which  will  remove  the  oxids  is  a  mooted  question. 
It  has  been  stated  that  the  washing  of  an  amalgam  mass  increases  its 
shrinkage  (Flagg).  On  the  other  hand  it  has  been  observed  that 
washed  amalgams  retain  their  color  better.  It  is  difficult  to  see  how 
the  washing  could  aifect  the  integrity  of  the  set  mass  unless  oxidizing 
substances  were  left  in  it ;  and  this  is  clearly  contraindicated  by  the 
maintenance  of  color  in  washed  amalgam.  The  writer  prefers  wash- 
ing the  plastic  mass  in  chloroform  j)rior  to  expressing  the  surplus  of 
mercury. 

'  It  is  to  be  recalled  in  this  connection  that  Dr.  Black's  measurements  are  made  with 
instruments  of  unequalled  accuiacy,  those  of  previous  observers  with  comparatively  crude 
instruments. 

*  Private  communication. 


USE  OF  AMALGAM.  299 


Use  op  Amalgam. 


It  is  to  be  understood  that  amalgam  is  to  be  employed  only  in  those 
conditions  and  situations  which  clearly  indicate  it  as  the  proper  mate- 
rial. As  a  general  rule,  it  is  excluded  from  the  ten  anterior  teeth  of 
each  jaw,  although  this  rule  is  open  to  exceptions.  Its  anterior  limit 
of  application  is  usually  regarded  as  the  distal  surface  of  the  first  bicus- 
pid. Its  more  general  employment  has  been  greatly  reduced  in  many 
places  since  the  introduction  of  what  are  known  as  combination  fillings 
(see  Chapter  XIV.),  and  by  improvement  in  the  forms  and  character  of 
artificial  crowns. 

The  first  class  of  cavities  to  which  amalgam  is  applied  are  those 
which  extend  beneath  the  gum  margin  ;  the  second,  buccal  cavities ;  the 
third,  compound  cavities ;  the  fourth,  approximal  cavities  ;  the  fifth, 
cavities  upon  the  masticating  faces  of  the  teeth.  These  are  the  classes 
in  which  gold  is  most  difficult  of  introduction  and  of  proper  shaping 
and  finishing,  in  the  order  named.  Amalgam  should  rarely  or  never  be 
packed  against  dentinal  or  enamel  walls  without  the  interposition  of  a 
layer  which  will  prevent  either  the  discoloration  of  the  dentin  or  the 
bluish  appearance  noted  when  amalgam  underlies  enamel. 

The  shaping  of  cavities  for  the  reception  of  amalgam  fillings  (see 
Chapter  VII.)  should  be  done  with  such  care  as  will  give  assurance 
of  the  permanent  retention  of  the  filling  and  the  perfect  sterilization  of 
the  dentin  before  and  during  its  introduction. 

The  separation  of  the  teeth,  removal  of  gum  overhanging  cavity 
margins,  and  breaking  down  of  frail  enamel  walls  by  means  of  chisels, 
precede  the  filling. 

The  rubber  dam  is  to  be  adjusted  where  and  when  possible,  with  such 
care  that  an  exclusion  of  the  fluids  of  the  mouth  is  assured  durino-  the 
shaping,  sterilizing,  and  filling  of  the  cavity.  As  Dr.  Black  has  shown,^ 
much  of  the  permanency  of  form  of  an  amalgam  mass  depends  upon 
the  even  distribution  of  the  constituents  ;  it  is  evident  that  every  aid  to 
this  end  should  be  utilized,  an  important  one  being  that  the  mass  should 
be  packed  into  a  cavity  having  but  one  orifice,  that  for  the  introduction 
of  the  filling. 

With  the  data  relative  to  dental  amalgams  which  have  been  given, 
it  is  evident  that  a  dental  amalgam  mass  is  by  no  means  simple,  but  is 
a  very  complex  body.  If  sufficient  mercury  has  been  used  to  eff'ect 
solution  of  the  alloy  particles  the  mass  will  consist,  first,  of  a  quantity 
of  a  chemical  amalgam — /.  e.  one  in  which  the  metals  are  united  in 
atomic  ratios — this  being  surrounded  by  one   or  more   other  distinct 

^  Dental  Cosmo.%  1895,  vol.  xxxvii.  p.  553. 


300 


PLASTIC  FILLING   MATERIALS. 


amalgams,  each  liaving  its  own  time  of  scttino:  and  rate  of  contraction. 
If  only  enough  nierenry  has  been  used  to  make  a  creaky  mass  the  sur- 
faces of  each  aUoy  particle  are  covered  hy  an  amalgam  of  indefinite 
composition  which  acts  as  a  cement  binding  the  jiarticles  together.  In 
this  line  the  same  experimenter  has  shown  that  mixing  the  alloy  and 
mercury  in  a  mortar  by  means  of  a  pestle,  wringing  the  surplus  mer- 
curial solvent  from  the  mass  by  means  of  heavy  pliers,  and  ]>acking  the 
filling  with  steel  burnishers  are  all  influences  which  lessen  the  strength 
of  the  completed  filling. 

The  conditions  are  now  a  prepared  and  sterilized  cavity  ;  any  miss- 
ing wall  re(piired  to  give  four  sides  has  been  replaced  by  a  properly 
adjusted  matrix  (sec  Fig.  242,  Chapter  XII.). 

Fkj.  208. 


Dr.  Herbst's  matrix. 


Matrices. — Matrices   may  be  readily  and  quickly  formed  by  cut- 
ting strips  from   a  sheet  of  very   thin   steel  which  has  been  annealed 


Fig.  269. 


Fig.  270. 


Herbst  pliers. 


and    polished.     By  means  of  contouring    jiliers    the    matrix    is  given 
the   correct   contour,    then    wedged    or   tied    into    place.      They    must 


USE  OF  AMALGAM. 


301 


be  so  adjusted  that  they  are  immovably  held  during  the  filling  ope- 
ration. 

A  rapid  method  of  forming  a  matrix  is  that  of  Dr.  Wilhelm  Herbst : 
A  strip  of  German  silver  No.  33,  wide  enough  to  extend  from  the 
cervical  margin  of  a  cavity  to  its  mouth,  and  long  enough  to  more  than 
embrace  the  tooth,  is  passed  around  the  tooth  (see  Fig.  268) ;  the  strip 
is  caught  near  its  extremities  by  a  pair  of  Herbst  pliers  (Figs.  269, 
270)  and  drawn  taut ;  the  pliers  pinch  the  metal  into  close  adaptation 
to  the  tooth  walls.  Held  by  the  pliers  the  matrix  is  withdrawn,  the 
line  of  junction  touched  with  zinc  chlorid  solution,  and  soldered  over 
an  alcohol  or  Bunsen  flame  with  soft  solder.  The  matrix  is  replaced 
upon  the  tooth,  the  rubber  dam  applied,  and  the  matrix  pressed 
against  the  cervical  margin  of  the  cavity  by  means  of  a  wooden 
wedge. 

The  matrices  of  Guilford  and'  those  of  Brophy  (Figs.  240,  241, 
Chapter  XII.)  are  operated  upon  a  common  principle ;  the  band  which 
most  nearly  fits  the  periphery  of  the  tooth  is  adapted,  then  drawn 
into  close  apposition  with  the  tooth  by  means  of  the  screw  appli- 
ances. 

The  matrix  of  Woodward  is  one  of  the  most  convenient.  Its  mode 
of  application  is  shown  in  Fig.  242,  Chapter  XII. 

The  Miller  matrix  (Fig.  271)  is  useful  and  adapted  for  the  class 
of  cavities   shown  in  Fig.  272,  as  held  in  contact  with  cervical  mar- 

FiG.  271 


gins  through  the  action  of  the  duplex  spring  leaflets.  Fig.  272. 

When  necessary  a  wooden  wedge  is  forced  between 
the  leaflets. 

(For  other  forms  and  applications  of  matrices  see 
Chapter  XII.) 

Mixing  the  Amalg-am. — It  is  usually  recom-  MiUer  matrix  adjusted. 
mended  that  the  proportion  of  mercury  and  alloy  be  determined  by 
weight.  An  amount  of  alloy  is  first  weighed,  then  weighed  additions 
of  mercury  are  added  to  it  sufficient  to  make  a  plastic  mass,  when  the 
two  are  to  be  mixed  together;  the  relative  amounts  of  mercury  and 
alloy  are  to  be  gauged  and  recorded  for  each  formula  of  alloy.  With 
the  "  submarine  "  alloy  of  Flagg— 60  silver,  35  tin,  and  5  copper— the 


302 


PLASTIC  FILLING  MATERIALS. 


ratio  is  equal  parts  by  wx-i^ht  of  tilings  and  nu  r- 
cury.  When  a  mortar  is  used  for  making  tlic  auud- 
uani,  one  of  glass  and  having  a  glass  pestle  (see 
Fiirs.  273,  274)  is  to  be  preferred.  Mixing  in  the 
palm  of  the  hand  is  a  dirty  process,  the  hand  and 
Hiigers  becoming  nuicii  discolored  by  the  metallic 
oxids. 

Fig.  273. 


Fi.;.  1271. 


Glass  mortar. 


Glass  pestle. 


A  rubber  mortar  (Fig.  275)  to  be  received  in  the  palm  of  the  hand 
has  been  devised  by  Dr.   Genese.     In  view  of  deductions  from  Dr. 


Dr.  Genese's  rubber  mortar. 


Black's  experiments  this  latter  method  of  mixing  is  regarded  as  usually 
the  preferable  one. 

The  filings  are  placed  in  the  receptacle,  the  mercury  is  added,  and 
the  mass  is  triturated — if  in  a  mortar,  by  the  pestle,  if  in  the  rubber 
basin,  by  the  forefinger  guarded  by  a  rubber  finger-stall.     When  the 


ZrSE  OF  AMALGAM. 


303 


amalgamation  appears  to  be  complete  the  mass  is  transferred  to  the 
hand  and  kneaded,  then  pressed  into  a  ball.  It  is  next  enclosed  in 
stout  muslin,  or  China  silk  as  recommended  by  Dr.  C.  E.  Kells,  Jr., 
and  the  surplus  mercury  expressed  by  wringing ;  when  no  more  mer- 
cury appears  through  the  muslin,  the  button  is  removed  :  it  should  break 
with  a  clean,  white  fracture  surface. 

Another  method  of  mixing  the  filings  and  mercury  is  that  of  Fletcher. 
Filings  and  mercury  are  placed  in  a  long  glass  tube  which  is  shaken  vio- 
lently until  amalgamation  is  complete. 

The  Packing-  Operation. — Several  devices  have  been  invented  for 
the  purpose  of  carrying  the  amalgam  to  the  tooth  cavity,  one  of  the 

Fig.  276. 


most  simple  being  shown  in  Fig.  283,  and  another  in  Fig.  284.     An- 
other excellent  instrument  is  shown  in  Fig.  285,  one  end  having  ser- 


FiG.  277. 


rated   points   which   engage  the   soft   amalgam,  the   other   a   plugger 
head. 

Numerous  methods  have  been  advanced  and  advocated  for  the  pack- 
ing operation.  The  one  commonly  followed  is  that  of  burnishing  the 
amalgam.  This  has  been  shown  by  Dr.  Black  to  weaken  the  mass.  A 
small  piece,  rarely  more  than  a  cube  of  |^  in.  side,  is  carried  to  the  deep- 
est and  most  inaccessible  recess  of  the  cavity  and  pressed  against  its 
walls  by  tapping,  burnishing,  or  uniform  pressure.  Dr.  Flagg's  method 
is  by  tapping.  Each  successive  piece  of  amalgam  is  tapped  upon  by  the 
packing  instruments  until  it  combines  with  its  predecessor  and  is  per- 
fectly adapted  to  the  cavity  walls.  The  set  of  instruments  shown  in 
Fig.  279  are  those  by  which  this  process  is  accomplished — Nos.  30-34 
being  packing  instruments,  while  the  others  are  shapers. 


304 


PLASTIC  FILLING  MATERIALS. 


A  convt'iiii'iit  and  utlcetive  sot  of  instrumcuts  lor  accoiuplisliing  the 
packing  are  shown  in  Figs.  280-282. 


Fig.  '27!t. 


30      31       32       33        34       3.")        3fi        37  38         39 

Dr.  J.  Foster  Flagg's  amalgam  and  zinc  filling  iiistruini-nts. 


Dr.  W.  G.  A.  Bonwill  has  advised  a  method  wliich  accomplishes  the 
removal  of  surplus  mercury  and  the  even  distribution  of  the  mass, 


Fig.  280. 


Woodson's  double-end  amalgam  instruments. 


during  the  progress  of  the  filling.  Small  squares  of  folded  bibulous 
paper  are  caught  in  the  jaws  of  pliers  and  laid  ujion  the  amalgam, 
when  the  exertion  of  pressure  by  means  of  amalgam  pluggers  or 
pliers  forces  out  the  surplus  solvent  and  it  is  wiped  away  with  the 
paper.  The  same  end  is  also  accomplished  by  the  use  of  bulbous 
points  of  soft  rubber. 

When  through  either  method  the  cavity  is  more  than  half  full,  the 
remainder  of  the  amalgam  mass  is  wrung  out  to  express  more  mercury, 
and  the  packing  is  resumed  imtil  the  cavity  is  more  than  full. 

At  the  later  stages  of  the  filling  the  process  of  wafering  is  usually 


USE  OF  AMALGAM. 


305 


followed.  By  means  of  chamois  and  heavy  pliers  (Figs.  283,  284)  the 
amalgam  mass  remaining  is  compressed  into 
a  wafer,  driving  the  surplus  mercury  through 
the  pores  of  the  chamois.  The  amalgam  is 
put  in  a  piece  of  chamois,  and  the  chamois 
sack  A  is  entered  between  the  beaks  b  and 
c  (the  latter  a  roller) ;  closing  the  handles 
of  the  instrument  progressively  squeezes  out 
the  mercury  till  any  desired  degree  of  dryness 
is  attained.  When  the  amalgam  is  squeezed 
to  the  requirements  of  the  operator,  the  han- 
dles are  released,  and  the  spring  opens  the  ap- 
pliance. The  action  is  analogous  to  the  finger 
and  thumb  movement  in  common  use,  but  is 
much  more  powerful,  and  therefore  more  cer- 
tain and  more  uniform.  Small  sections  of  the 
wafer  are  laid  upon  the  half-completed  filling 
and  tapped  into  a  union  with  it.  The  cavity 
is  more  than  filled,  and  at  the  completion  of 
the  packing  the  amalgam  should  cut  as  though 
nearly  set. 

Another  and  excellent  method  where  applicable  is  to  shape  small 
pieces  of  half-vulcanized  rubber  and  cement  them  upon  broken  excava- 

FiG.  284. 


Mercury  expresser. 


Flagg's  wafering  pliers. 

tors,  and  use  them  as  pluggers  during  the  later  stages  of  the  filling. 
The  fluid  cementing  amalgam  will  have  its  surplus  mercury  expressed 
about  the  sides  of  the  plugger. 

Still  another  method  is  to  fill  the  cavity  more  than  half  full,  then 
cut  away  the  softened  portion,  and  complete  the  filling  with  drier  amal- 
gam. Fillings  the  initial  portions  of  which  have  been  introduced  com- 
paratively dry  are  more  homogeneous  and  are  less  likely  to  discolor 
and  crevice  than  when  more  fluid  amalgam  has  been  used  to  begin  the 

20 


306  PLASTIC  FII.IJSi;    MATERIALS. 

filliiijX.  An  oxamiiiMtioii  ot"  an  anial<;ani  tillini;-  iinnicdiatcly  al'tcr  com- 
pletion will  show  the  marginal  jtortions  to  contain  the  softer  amalgam, 
tlic  hanlcr  hcint^  in  the  more  central   jiarts. 

The  too  common  practice  of  j)la<'inii-  in  the  prepared  cavitv  sutlicient 
amalgam  in  one  mass  to  nearly  or  <juite  halt"  till  it,  is  I'anlty.  ]iy  no 
means  can  this  method  si'cnre  the  accnracy  of"  adaptation  ot"  tilling 
material  to  cavity  walls  which  is  demanded  of  a  correct  filling. 

At  the  completion  of  the  packing  operation,  unless  the  filling  has 
been  finished  by  watering,  the  surface  will  be  found  still  soft.  It  has 
been  recommended '  that  small  pieces  of  annealed  No.  1  gold  foil  be 
burnished  over  the  surface  of  the  amalgam,  until  no  more  gold  can  be 
amalgamated  by  this  means,  when  the  filling  will  be  found  quite  hard. 
The  indefinite  cementing  amalgam  has  combined  with  the  gold,  for 
which  mercury  has  a  strong  affinity,  and  formed  a  distinct  amalgam 
upon  the  surface  of  the  filling  proper.  As  amalgams  of  gold  are  com- 
])aratively  soft,  it  is  advisable  to  first  fill  the  cavity  more  than  fidl,  apply 
the  gold  foil,  then  scrape  the  filling  dowai  to  the  cavity  margins.  Dr. 
Rhein's  procedure  is  to  fill  the  cavity  with  plastic  amalgam  and  rub  on 
the  pieces  of  gold  until  no  more  gold  is  amalgamated.  This  gold  amal- 
gam is  permitted  to  remain.  The  surplus  of  mercury  may  also  be  con- 
veniently removed  by  absorbing  it  from  the  surface  of  the  filling  by 
pieces  of  sponge  or  crystal  mat  gold. 

An  amalgam  filling  should  be  hard  enough  to  resist  cutting  before 
the  rubber  dam  is  removed. 

In  those  situations  where  the  rubber  dam  cannot  be  successfully 
employed,  it  is  the  accepted  practice  to  prepare  the  cavity,  sterilize  it, 
when  access  is  difficult  sealing  a  (germicide  in  the  cavitv  for  a  dav:  next 
adjust  a  napkin,  and  having  mixed  a  submarine  amalgam  (one  contain- 
ing copper  and  a  high  percentage  of  silver),  the  cavity  is  dried  as  well 
as  possible  ;  a  piece  of  the  amalgam  is  then  carried  to  the  deepest  recess 
of  the  cavity  and  ciuickly  and  forcibly  compressed  with  a  mass  of 
bibulous  paper.  Another  ])iece  of  amalgam  is  added  and  compressed, 
driving  the  surplus  mercury  from  the  amalgam.  While  the  napkin  is 
in  position,  a  mass  of  temporary  stopping  (which  see)  is  softened  and 
placed  in  the  remainder  of  the  cavity.  A  knife  blade  passed  over  the 
edges  of  the  amalgam  will  remove  overhanging  portions.  At  a  subse- 
quent visit,  the  rul)ber  dam  is  adjusted,  the  temporary  stopping  is 
removed,  and  the  filling  completed  with  amalgam. 

If  the  operator  prefer,  the  rubber  dam  may  be  adjusted  at  once  and 
the  filling  completed  at  one  sitting  ;  the  former  method  is,  however,  pre- 
ferable, as  the  cervical  portion  of  the  filling  may  l)e  perfectly  finished, 
and  not  be  in  danger  of  displacement,  while  the  second  section  is  packed. 
^  Uttolengui's  Methods  of  Filling  'Teeth,  "  Method  of  M.  L.  Rhein." 


USE  OF  AMALGAM.  307 

In  cavities  extending  beneath  the  gum,  and  opening  broadly  upon  a 
surface  of  a  tooth  where  discoloration  would  be  highly  objectionable, 
the  cervical  half  of  the  filling  is  made  of  a  submarine  amalgam  and  is 
completed  with  an  amalgam  containing  gold,  which  will  retain  a  better 
color.  Should  the  external  face  of  the  filling  be  readily  visible  and  not 
subjected  to  the  stress  of  mastication,  its  outer  surface  is  made  of  a 
wafer  of  an  amalgam  containing  zinc,  known  as  a  facing  amalgam. 
Copper  amalgam  is  used,  when  used  at  all  (and  that  is  but  seldom), 
upon  the  distal  and  buccal  walls  of  third  molars,  in  cavities  extending 
under  the  gum  line,  which  are  difficult  of  access  and  to  sterilize,  and 
which  cannot  be  properly  dried. 

A  cavity  is  prepared  which  need  be  but  slightly  undercut.  A  pellet 
of  the  copper  amalgam  is  placed  in  an  iron  spoon  (Fig.  285)  held  above 

Fig.  285. 


Heating  spoon  for  copper  amalgam. 

a  Bunsen  flame  until  globules  of  mercury  appear  upon  its  surface,  when 
it  is  quickly  crushed  in  a  mortar  and  pounded  until  made  into  a  paste. 
There  can  be  no  objection  to  washing  the  soft  mass  in  aqua  ammonia  to 
dissolve  and  remove  oxids  which  later  form  discoloring  salts,  and  thus 
permit  a  chemical  union  of  the  metals  which  would  be  prevented  by 
their  presence.  A  napkin,  or  always  when  possible  the  rubber  dam, 
is  adjusted,  and  the  filling  inserted  in  sections.  At  the  end  of  the  oper- 
ation the  filling  should  be  firmly  compressed  with  a  broad -bladed  spatula. 

In  by  far  the  greater  number  of  cases  in  which  amalgam  was  at  one 
time  used  alone,  it  is  now  the  accepted  practice  to  place  a  lining  of  a 
zinc  cement,  and  add  the  amalgam  as  a  resistant  and  insoluble  covering. 

In  cavities  which  approach  the  pulp  the  same  precautions  are  taken 
for  the  prevention  of  thermal  shock  as  with  gold. 

The  most  difficult  class  of  cases  in  which  to  obtain  satisfactory  results 
with  amalgam  are  those  opening  alone  upon  the  approximal  surfaces  of 
bicuspids  and  molars.  While  it  is  true  that  amalgam  may  be  manip- 
ulated in  spaces  impossible  with  gold  foil  even  in  soft  cylinders,  it  is 
essential  that  sufficient  room  be  obtained  for  the  perfect  introduction  of 
the  material  and  its  subsequent  trimming  and  polishing ;  for  polishing 
is  quite  as  necessary  an  operation  with  amalgam  as  with  gold.  This 
space  is  obtained  either  through  wedging  or  by  cutting  through  the 
occlusal  face  of  the  tooth  into  the  cavity. 

Space  is  to  be  obtained  and  amalgam  packed  in  such  a  manner 
that  the  amalgam  at  the  completion  of  the  operation  shall  exhibit  no 


308  PLASTIC  FILLING  MATERIALS. 

evidence  of  pastiness.  To  insure  the  removal  of  the  exeess  of  the  sol- 
vent, goKl  foil  may  he  imiMishcd  over  it  as  already  described  until  it 
re(jnires  some  etlort  to  cut  the  mass  with  a  lancet  blade.  Amalgam 
when  set  is  more  ditlicult  to  cut  and  polisii  tiian  gold  ;  the  greater  por- 
tit»n  of  the  cai-xing  is  therefore  done  at  the  same  sitting  as  the  filling, 
but  should  never  be  uudei-taken  while  the  filling  is  soft.  It  should  be 
in  such  a  condition  that  it  is  necessary  to  carve,  not  smear,  it  into  shape. 
A  suitable  cutting  instrument  of  the  form  of  Nos.  37  to  40  of  Flagg's 
set  (see  Fig.  279)  is  passed  first  across  the  cervical  border  of  the  filling, 
removing  any  excess  due  to  imperfect  contact  of  the  matrix  with  the 
cervical  margin  of  the  cavity ;  next  the  lateral  borders  are  carved,  and 
then  the  masticating  surface.  The  body  of  the  filling  is  left  full,  so  that 
after  two  days,  when  the  filling  receives  its  final  dressing  and  polishing 
with  cuttlefish  disks,  strips,  pumice,  etc.,  the  filling  will  be  reduced  to 
correct  contour.  A  polished  amalgam  filling  will  retain  an  untarnished 
surface  when  an  unpolished  one  will  discolor  very  objectionably. 

Many  of  the  cases  in  which  it  was  at  one  time    the  usual   j)rac- 
tice   to    fill    or    restore    almost   entire   tooth    crowns    with    amalgam, 
Fio.  286.  are    trimmed    down,  shaped,    and    artificial 

crowns  applied.  One  class  of  cases  is  fre- 
quently seen  in  which  the  indication  is  for 
an  enormous  amalgam  filling  rather  than  an 
artificial  crown  ;  this  is,  the  loss  of  the  dis- 
tal half  of  the  crown  of  a  molar.  As  a 
rule  the  teeth  are  pulpless,  or  it  is  necessary 
Restoration  of  lower  molar  with  ^o  devitalize  the  pulp.  The  appearance  of 
amalgam.  the  crown  after  the  removal  of  carious  den- 

tin and  cutting  away  frail  enamel  walls  is  seen  in  Fig.  286. 

A  Herbst  matrix  is  fitted,  closely  embracing  all  the  margins  of  the 
cavity.  The  rubber  dam  is  adjusted.  It  is  of  course  understood  that 
the  root  canals  have  been  properly  sterilized  and  filled.  The  posterior 
canal  is  drilled  out  for  about  \  in.  and  screw-tapped.  A  thin  solution 
of  zinc  phosphate  is  mixed  and  the  tip  of  a  screw  to  fit  the  tapped 
root  has  its  ])oint  di])ped  into  the  cement,  and  then  (piickly  scrcAved 
into  place.  The  amalgam  is  packed  in  larger  masses  than  usual,  using 
bibulous  paper  to  compress  it  about  the  screw  and  into  such  scant 
undercuts  as  may  be  secured  in  the  anterior  portion  of  the  tooth.  The 
filling  is  comj)leted  with  amalgam  M'afers. 

Such  a  filling  should  be  well  set  before  the  rubber  dam  is  removed. 
The  upper  surface  is  carved  into  cusps  and  sulci  to  occlude  properly 
with  the  antagonizing  teeth.  The  matrix  should  remain  for  twenty- 
four  hours,  when  it  may  be  split  and  removed.  If  the  matrix  has  been 
exactly  adjusted  there  should  be  no  trimming  of  the  margins  required, 


USE  OF  AMALGAM. 


309 


no  carving  of  contour,  and  no  smoothing,  the  amalgam  being  ready  for 
polishing  strips.  The  occlusal  surface  is  smoothed  and  polished  with 
moosehide  points  and  pumice,  using  a  stiif  brush  to  polish  the  sulci. 

Finishing. — The  process  of  finishing  hard  amalgam  fillings  is  simi- 
lar to  that  of  finishing  gold.  For  example :  a  compound  cavity  occu- 
pying the  approximal  and  occlusal  faces  of  a  molar.  A  fine  saw  is 
placed  in  a  frame  as  in  Fig.  287,  but  set  to  draw-cut  with  its  teeth 

Fig.  287. 


The  Kaeber  saw  frame. 


pointing  toward  the  frame.  The  blade  is  passed  above  the  cervical 
margin  of  the  filling,  engaging  any  projecting  amalgam,  which  is  then 
sawn  off.  It  is  just  as  essential  with  an  amalgam  as  with  a  gold  filling 
that  the  cervical  edge  should  be  exactly  flush. 

The  lateral  margins  of  the  filling  are  next  carved  smooth ;  strips  of 
emery  cloth  are  passed  into  the  interdental  space  and  the  filling  smoothed 
and  rounded,  completing  this  portion  of  the  operation  with  emery  strips 
of  the  finest  grit. 

Linen  tapes  or  metal  polishing  strips  are  next  charged  with  pumice 
and  passed  over  the  surfaces  until  they  are  smooth  and  the  margins  are 
perfect.  The  occlusal  portion  is  polished  by  means  of  rubber  or  moose- 
hide  points  and  pumice. 

Should  it  be  a  plain  approximal  filling,  not  a  "  contour,"  the  saw  is 
used  to  cut  aw^ay  surplus  amalgam,  and  the  polishing  accomplished  by 
means  of  disks  and  powders. 

Fillings  upon  the  buccal  surfaces  of  teeth  are  smoothed  by  means 
of  disks  and  polished  with  rubber  cups  or  disks  and  pumice. 

Gutta-percha. 

Origin. — The  gutta-percha  of  commerce  is  the  coagulated  juice  of 
the  Isonandra  gutta,  a  tree  of  the  order  of  Sapotacece.  The  juice  is 
found  in  all  trees  of  this  order,  but  some  specimens  are  of  much  higher 
value  than  others.  That  from  Borneo  is  regarded  by  manufacturers  as 
being  inferior  ;  it  is  the  variety  from  which  the  name  is  derived — Malay, 
gatah  or  gittah,  gum,  and  pertja,  a  tree.  The  gutta  Tuban  from  Singa- 
pore is  regarded  as  a  superior  variety. 


310  PLASTIC  FILIJya   MATERIALS. 

Tlio  mode  of"  scoiii'iiiu-  \\\v  juice  is  hy  ta|)|)iiiti-  the  caiiihiiiiu  lavor  of 
the  tree  and  eatcliintr  tlic  juice  as  it  exudes.  From  tliis  stage  to  its 
formation  into  slieets  it  nndertroes  seveial  j)rt)eesses  (see  works  on  gutta- 
]HM-cha);  it  is  |)ossihle  that  in  some  of  these  o})erations  it  may  have  its 
texture  injured  1)V  overheating. 

"The  j>uriried  gutta-jx'rcha  probably  consists  of  a  liy(b'ocarbon  fj>nre 
gutta)  having  tlie  formuhi  Ci^H,,; ;  ali)ane,  C,yH,gO;  fluavile,  ('^oHrt^Oj ; 
and  a  variabk'  comj)ound  named  guttane.  Pure  gutta  possesses  all  the 
good  qualities  of  gutta-percha  in  a  much  enhanced  degree,  becoming 
soft  and  plastic  on  heating  and  hard  and  tenacious  on  cooling  without 
l)eing  in  the  least  brittle.  Tlie  resins  appear  to  be  simply  accessory 
components  -which  have  a  decidedly  detrimental  effect  when  they  pre- 
ponderate. AVater,  Avood,  fibers,  bark,  sand,  etc.,  occur  as  mechanical 
impurities  of  gutta-percha."     (Obach.) 

History. — Gutta-percha  was  introduced  into  dental  practice  as  a  fill- 
ing material  about  the  year  1847.  Soon  after  this  a  secret  preparation 
was  introduced  by  a  Dr.  Hill,  which  received  his  name.  Numerous 
alleged  analyses  of  Hill's  stopping  have  been  given,  all  of  wliieh  are 
untrustworthy.  It  was  found  to  subserve  so  useful  a  ])urpose  that  it 
rcccivetl  the  tribute  of  wide  imitation  ;  in  fact,  the  white  gutta-})ercha 
preparations  of  the  present  day  had  their  foundation  in  this  imitation. 
There  is  no  entirely  trustworthy  evidence  that  the  original  was  superior 
to  the  best  of  contemporary  preparations. 

As  at  present  employed  as  a  filling  material  gutta-percha  is  in  two 
forms,  the  first  the  w'ell-known  pink  gutta-percha  ba.se  plate,  which  is 
colored  by  the  insoluble  sulfid  of  mercury,  the  second  the  white  prep- 
arations, made  firmer  in  texture  by  additions  of  the  soluble  zinc  oxid. 
The  .specimens  of  crude  gum  differ  as  to  the  amount  of  heat  re(piired 
to  soften  them  to  an  (>qual  degree.  Dr.  Flagg '  states  that  the  speci- 
mens requiring  the  greatest  degrees  of  heat  for  softening,  prior  to  the 
addition  of  the  zinc  oxid,  afford  the  best  dental  gutta-perchas.  The 
method  of  making  the  gutta-])ercha  of  dentistry  is  by  softening  a  mass 
of  the  brownish-vellow  gum  on  a  slab  which  has  been  heated  over  boil- 
ing  water,  and  driving  zinc  oxid  into  the  softened  mass  by  a  process 
of  kneading,  using  a  Avedge-shaped  steel  instrument  as  the  kncader.  It 
requires  infinite  patience  and  much  time  to  distribute  the  powder  evenly 
throughout  the  mass.  Overheating  the  material  at  any  stage  of  its 
manufacture  or  manipulation  is  ruinous  to  its  texture. 

Classes. — Gutta-perehas  are  divided  into  three  classes  according  to 

the  temperature  of  softening  :  Low  heat,  softening  below  200°  F.     3Ie- 

dium  heat,  becomes  plastic  at  200°  to  210°  F.    Jflf/h  heat,  210°  to  218°  F. 

The  low-heat  specimens  contain  1  })art  by  weight  of  gutta-percha  to  4 

^  Plastics  and  Plastic  Filling. 


GUTTA-PERCHA.  311 

of  zinc  oxid ;  in  medium-heat  the  ratio  is  1  to  6  or  7 ;  and  in  the  high- 
heat  specimens  the  gutta-percha  is  almost  saturated  with  zinc  oxid. 

Physical  Properties. — Gutta-percha  is  an  almost  perfect  non-con- 
ductor both  of  heat  and  electricity.  It  is  less  hard  and  rigid  than  any 
other  filling  material.  It  contracts  in  hardening,  i.  e.  cooling.  Softened 
masses  of  it  are  coherent  when  dry,  but  not  when  wet.  Its  color  may 
be  made  to  resemble  that  of  the  teeth.  To  vital  tissues  it  is  the  most 
bland,  unirritating  filling  material  known. 

After  it  has  served  as  a  filling  for  a  greater  or  less  period  it  is  found 
to  have  increased  in  hardness  and  difficulty  of  softening,  and  its  surface, 
and  perhaps  its  substance,  has  become  porous  in  variable  degree.  The 
increased  hardness  is  observed  in  such  situations  as  those  in  which 
putrefactive  decomposition  occurs  ;  that  is,  in  places  where  there  is  an 
evolution  of  hydrogen  sulfid ;  the  gutta-percha  apparently  undergoes  a 
species  of  vulcanization.  It  becomes  somewhat  porous  in  those  situa- 
tions where  the  formation  of  a  solvent  is  active  (lactic  acid),  which 
abstracts  the  soluble  zinc  oxid  from  the  mass.  The  pink  variety  con- 
taining the  insoluble  mercury  sulfid  does  not  become  porous,  but  wears 
with  a  comparatively  smooth  surface  when  subjected  to  attrition. 

Examining  in  detail  these  several  physical  properties  it  will  be  noted 
that  gutta-percha  has  but  one  property  in  common  with  gold — its  insol- 
ubility. Its  rational  employment  is  therefore  in  such  situations  and 
conditions  as  those  in  which  the  use  of  gold  is  contraindicated. 

Indications  for  its  Employment. — First,  in  its  several  forms  it  is 
employed  as  a  temporary  filling  material  for  both  the  temporary  and 
permanent  teeth.  Owing  to  its  non-conductivity  it  is  employed  near 
the  pulp ;  its  insolubility  recommends  its  use  at  the  cervical  margins  of 
cavities,  particularly  in  the  buccal  cavities  of  molars  which  do  not 
extend  to  the  masticating  surface,  where  the  non-resistance  of  the 
material  would  cause  its  rapid  wasting. 

This  is  the  most  common  of  the  situations  in  which  gutta-percha  is 
applied  :  very  deep  cavities  upon  the  buccal  surfaces  of  molars,  extend- 
ing beneath  the  gum,  and  having  ragged  enamel  margins,  the  orifice 
of  the  cavity  being  much  smaller  than  its  body.  Owing  to  its  non- 
irritating  quality,  the  condition  of  the  gum  in  contact  with  a  gutta- 
percha filling  remains  normal. 

It  is  used  in  approximal  cavities  of  the  anterior  teeth  which  have  a 
similar  form  to  those  just  described ;  also  in  labial  cavities,  particularly 
when  these  teeth  are  in  any  degree  loose.  For  example  :  in  a  cavity 
opening  alone  upon  the  distal  wall  of  a  canine  tooth  the  carious  process 
has  almost  invaded  the  pulp,  the  enamel  walls  unsupported  by  dentin 
still  retain  their  form  and  have  a  good  texture. 

Pink  base  plate  is  invaluable  for  the  temporary  filling  of  spaces  after 


312 


PLASTIC  FILLING  MATERIALS. 


wedging  and  also  the  cavities  to  be  subsequently  lllkd  with  nutul.  A 
mass  of  the  material  may  he  packed  into  such  spaces  and  be  permitted 
to  remain  for  months  if  <lesircd,  the  gum  in  contact  with  it  after  its 
prolonged  presence  exhibiting  no  indications  of  irritation.  Masses  of 
gutta-percha  may  be  packed  in  interdental  spaces  where  there  is  not 
sufficient  space  for  the  introduction  of  contour  fillings,  with  the  ]iurpose 
of  having  the  teeth  gradually  separated  by  the  impact  of  mastication; 
the  gutta-percha  acts  as  a  persistent  and  very  gradual  wedge. 

When  it  has  been  determined  that  an  excavated  cavity  is  unfit  for 
the  reception  of  a  permanent  filling,  gutta-percha  is  the  filling  material 
par  excellence. 

Although  it  is  stated  that  gutta-percha  shrinks  markedly  in  harden - 

Fig,  288. 


Flagg's  gutta-percha  softener  and  tool-heater. 


ing,  cavities  in  which  it  has  been  properly  placed  exhibit  no  evidences 
of  softening  after  the  material  has  been  worn  for  months,  or  it  may  be 


GUTTA-PERCHA. 


313 


Fig.  289. 


for  years.     Particularly  is  this  true  when  the  pink  variety  has  been 
employed  and  the  method  of  introduction  is  correct. 

Mode  of  Softening-. — Gutta-percha  should  never 
be  heated  beyond  a  point  which  permits  of  accurate 
adaptation  to  undercuts  and  frail  walls.  The  soften- 
ing should  be  gradual.  Any  heat  in  excess  of  this  is 
not  only  harmful  but  ruinous. 

For  its  proper  softening  some  device  is  necessary 
which  shall  permit  of  this  type  and  degree  of  heating 
(see  Figs.  288-290,  299). 

Fig.  288  illustrates  the  heater  of  Dr.  Flagg.  There 
are  three  metallic  shelves,  the  highest  of  which  receives 
the  least  amount  of  heat,  and  is  designed  for  softening 
low-heat  gutta-percha.  The  second  shelf  is  for  the 
softening  of  high-heat  specimens.  The  lowest  shelf 
and  rack  support  the  packing  instruments,  which  are 
kept  at  a  higher  temperature  than  the  filling  material. 

Fig.  289  illustrates  a  device  of  Dr.  L.  A.  Faught 
for  the  packing  of  gutta-percha.  The  heating  wires 
connect  at  the  bases  of  the  instrument  points,  which 
are  of  aluminum,  and  sufficient  heat  is  conveyed  to  the 
gutta-percha  to  maintain  it  in  a  plastic  state  during  the 
packing  operation. 

Instruments. — As  a  rule  the  instruments  used  in 
packing  gutta-percha  are  too  large  and  the  material 
itself  is  used  in  too  large  pieces.  If  the  cavity  is  of 
considerable  extent,  and  usually  it  is,  the  filling  should 
be  introduced  in  four  or  more  pieces.  It  is  preferable 
to  warm  all  the  packing  instruments  so  that  the  gutta- 
percha will  remain  plastic  until  perfectly  adapted. 

Manipulation. — The  rubber  dam  having  been  ad- 
justed, the  cavity  excavated  and  sterilized,  the  frail 
enamel    edges  broken  away,  without  yig.  290. 

any  particular  object  of  margin  form- 
ing, but  to  gain  space,  the  cavity  is 
dried  for  the  reception  of  the  gutta- 
percha. The  field  of  operation  should 
be  dry,  in  order  that  each  additional 
piece  of  gutta-percha  shall  adhere  to 
its  predecessor,  which  it  would  not  do 
if  wet.  A  softened  pellet  is  taken  upon  the  point  of  a 
probe  and  placed  in  the  most  inaccessible  portion  of 
the  cavity  and  tapped  into  accurate  contact  with  the  tooth  walls  (by 


Order     of     placing 
gutta-percha  peUets. 


Dr.  Faught's  electric 
heater. 


314 


PLASTIC  FILLING   MATERIALS. 


means  of  the  corkscrew  j)lii<;<»;cr  No.  3'2  or  No.  .')•')),  as  shown  in 
No.  1  of  Fig.  290.  A  second  jidlet  is  added  (No.  2)  and  similarly 
nianijjidated.  The  Xos.  3,  4  ])ellets  are  packed  in  the  order  sliown  in 
t\\v  liiiurc.  In  adding  the  last  piece  broad-faced  instrnnients  are  used, 
adapting  the  gutta-percha  accurately  t(»  the  niariiins  of  the  cavity.  The 
softened  gutta-percha  may  be  made  to  adhere  better  to  the  walls  of  the 
cavity  if  these  be  first  coated  with  one  of  the  lining  varnishes. 

Another  method  of  manipulation  is  to  line  the  walls  of  the  cavity 
with  ])ellets  until  a  cylindrical  cavity  remains.  A  cylinder  of  gntta- 
j)erc-ha  of  that  size  is  nearly  softened  and  pressed  firmly  into  the  cavity 
by  means  of  a  broad  spatula. 

Should  the  cavity  be  very  deep,  the  pulp  almost  exjiosed,  the  por- 
tion of  dentin  overlying  the  pulp  is  to  be  covered  by  a  thin  judlet  of  low- 
heat  gutta-percha  softened  sufficiently  to  permit  of  adaptation.  A  disk 
of  pink  gutta-percha  base  plate  answers  admirably  for  this  j)urpose. 

The  use  of  one  of  the  lining  varnishes,  noted  at  page  257,  especially 
the  cellidose  solution  known  as  kristaline,  previous  to  placing  the  pellets, 
will  insure  their  adhesion  to  the  cavity  walls  and  prevent  rocking  or 
tip])ing  of  the  mass  of  gutta-percha  during  the  operation  of  its  insertion. 
In  order  to  secure  the  best  results  the  kristaline  solution  should  be  thin 
when  applied,  and  the  solvent  conij)letely  evaporated  by  blasts  of  warm 
air  before  any  attempt  is  made  to  introduce  the  gutta-percha,  for  unless 
the  varnish  lining  is  fully  hardened  the  pellets  will  not  strongly  adhere 
to  the  surface  so  treated. 

Dr.  How's  Improved  Gutta-percha  Filling's. — Dr.  AV.  Storcr  How  ' 
has  published  a  method  of  packing  gutta-percha  which  is  as  excellent 
as  rational,  when  the  directions  given  are  closely  followed  : 

"Many  approximal  cavities  like   C,  Figs.   291,   292,   may  well  be 


Fig.  291. 


Fig.  292. 


Fig.  293. 


A— 


-A" 


Approximal  cavities. 

filled  with  gutta-percha,  and  such  as  C,  Fig.  292,  where  a  gold  filling 
would  show  through  the  thin  enamel  front,  can  better  be  filled  with 
suitable  gutta-percha.  The  section,  Fig.  293,  shows  the  angles  A,  A', 
which  should  be  given  the  enamel-edges  when  practicable,  and  in  any 
case  the  enamel-margin  should  have  a  squarely  defined  angle  at  its 
surface  border. 

"  Cervico-labial   or   buccal  cavities,  as   shown    in    Figs.  294-298, 

1  Denial  Cosmos,  1892,  vol.  xxxiv.  p.  281. 


O  UTTA-PERCHA.  31 5 

admit  of   permanent  gutta-percha    fillings.       Of    course  due  attention 
Fig.  294.  Fig.  295.  Fig.  296.  Fig.  297.  Fig.  298. 


Cervico-labial  and  buccal  cavities 


must  be  given  to  the  retention  of  the  fillings  by  enlarging  the  interior 
Walls  of  the  cavities  when  they  have  not  already  such  expansions. 
After  suitably  preparing  the  cavity,  it  should  be  made  as  dry  as  possible 
and  so  kept.  The  problem  of  conveniently  and  properly  softening 
pellets  of  gutta-percha  has  been  solved  by  the  production  of  the  ther- 
moscopic  heater  shown  in  Fig.  299,  which  approximates  the  exact  size 

Fig.  299. 


Thermoscopic  heater  for  gutta-percha. 

of  the  device.  The  heater  is  in  this  instance  made  of  steatite,  because 
of  its  heat-retaining  property  and  the  desirable  physical  qualities  of  its 
surface.  The  handle  is  of  wood,  at  the  opposite  end  from  which,  in 
the  centre  of  the  circular  recess,  is  a  small  disk  (^A)  of  metal,  fusible  at 
about  212°  F.  On  the  heater  near  the  metal  a  suitable  number  of 
gutta-percha  pellets,  as  1,  1,  are  placed,  and  the  heater  held  over  the 
flame  of  the  annealing  lamp  or  burner  (as  in  the  illustration)  until  the 
fusible  metal  melts,  when  the  heater  is  placed  on  a  piece  of  cardboard 
(or  an  empty  foil-book),  and  the  gutta-percha  will  be  found  to  be  prop- 
erly softened.  The  steatite  plaque  retains  the  heat  long  enough  for  an 
ordinary  operation,  but  if  the  metal  meantime  loses  its  fluidity  and  so 


316  PLASTIC  FILUXG   MATERIALS. 

indicat*;s  i\  loworintj  of  tlic  standnnl  licnt,  it  iniiy  be  <|iiicklv  restored 
by  a  moinont'.s  holdiiit;  of  tlie  lieater  over  the  flame,  wliieli  will  :iL:ain 
fuse  the  metal. 

*'  M'heii  the  flame  is  ajutlied  directly  under  the  metal,  as  in  the  ilhis- 
tration,  the  material  placed  at  1  will,  when  the  metal  is  seen  to  he  fused, 
bo  at  the  heat  of  near  208°  F.,  while  the  ])ellcts  at  2  will  be  heated  to 
about  200°,  those  at  8  and  4  to  near  194°  and  180°  respectively.  Of 
course  the  location  of  the  heat-source  will  j)n)(luee  correspondiufi;  varia- 
tions in  the  relative  temperatures  of  the  materials  as  severally  situated  ; 
but  with  a  visibly  detinite  standard  such  as  the  metal  A,  having  a  known 
fusing-point,  the  desired  degree  of  heat  may  repeatedly  be  produced  at 
any  place  on  the  receiving  surface  of  the  heater.  A  few  seconds'  contin- 
uance of  the  heater  over  the  flame,  after  the  metal  has  melted,  will  raise 
the  surface  heat  to  212°  or  215°,  as  the  case  may  be  ;  but  as  a  suitable 
indicator  for  a  high-heat  stopping,  a  button  (J5)  of  metal  fusing  at  230° 
is  provided  as  a  substitute  for  A,  which  is  first  melted  and  poured  out 
on  a  piece  of  clean  paper,  the  heater  cavity  being  undercut  so  that 
when  cold  the  metal  cannot  be  shaken  out.  The  boiling  of  a  few 
drops  of  water  in  the  heater  cavity  will  likewise  serve  to  indicate 
the  pro])er  temperature,  but  the  fusible  metal  is  in  every  way  j)ref- 
erable.  The  best  plan  is  to  hold  the  heater  over  the  flame  until  the 
Fio  SOO  metal    melts,  set    down    the    heater,    blow    hot   air 

into  th(>  previously  prepared  and  dry  cavity  until 
the  tooth  is  sensibly  warm,  hold  the  heater  again 
over  the  flame  to  melt  the  metal,  and  then  with  a 
suitable  broad  and  cold  instrument  pick  from  the 
heater  a  pellet  or  group  of  pellets  sufiicient  to  a  little 
more  than  fill  the  cavity,  and  by  a  quick,  firm,  rock- 
Trimming  margins  of  iug  pressure  force  the  mass  into  the  cavity  as  if  it 
gutta-percha  filling.      ^^^^^,^    ^^^^^-^^    ^^    ^^j,^    ^^    imprcssion  of  thc  Same. 

Then  dip  the  instrument  into  ice-water,  wipe  dry,  and  hold  it  firmly 
against  the  filling  for  one  or  more  minutes,  after  which  with  a  keen- 
edged  thin  blade  pare  off  the  surplus,  cutting  from  the  centre  obliquely 
toward  the  margin,  as  in  Fig.  300,  taking  great  care  that  the  filling  // 
shall  be  flush  with  the  cavity  margin  at  every  point,  as  at  A,  A',  Figs. 
301  and  302. 

"  Access  to  approximal  cavities,  as  C,  C,  Figs.  291  and  292,  will 
seldom  permit  the  instantaneous  mass-method  just  described,  but  in 
many  such  cases  a  w^arm,  broad,  flat  blade,  as  stiff  as  the  space  will 
admit,  can  by  repeated  quick  pressures  be  made  to  squeeze  the  soft  mass 
into  the  cavity  of  the  warmed  tooth,  and  be  instantly  followed  by  a  very 
thin  strip  of  metal  held  tightly  in  both  hands  and  wrapped  with  hard 
pressure  over  the  filling  around  that  side  of  the  tooth,  to  both  condense 


GUTTA-PERCHA. 


317 


and  contour  the  plastic  and  produce  the  closest  adaptation  of  the 
material  to  all  parts  of  the  cavity  walls. 

"  There  is  good  reason  for  the  belief  that  the  common  mode  of  suc- 
cessively introducing  small  pieces  of  imperfectly  softened  gutta-percha 
into  a  comparatively  cold  cavity,  and  employing  instrument  points  more 
or  less  heated  for  packing  the  cooled  plastic  against  one  side  of  the 
cavity  after  the  other,  must  in  the  nature  of  the  case  result  in  a  leaky 
filling,  such  as  gutta-percha  is  commonly  said  to  make,  whereas  the 
defect  is  due  not  to  the  material,  but  to  its  inconsiderate  manipulator. 

"  In  order  to  definitely  determine  whether  or  not  suitably  softened 
gutta-percha  inserted  by  the  mass-method  will  make  a  moisture-tight 
filling,  some  procelain  teeth  of  natural  size  and  forms  were  made,  hav- 


FiG.  301. 


Fig.  304. 


Fig.  305.         Fig.  306. 


ing  cut  in  them,  prior  to  baking,  cavities  of  the  class  shown  in  Figs. 
291-298.  These  cavities  have  been  filled  with  gutta-percha,  leaving 
a  surplus  over  the  margins,  as  at  a'  a',  Fig.  303,  and  when  quite  cool 
paring  them  flush  as  at  A,  A',  Figs.  301,  and  302,  and  after  several  days' 
immersion  in  dilute  aniline  ink,  the  fillings  have  been  removed  without 
a  trace  of  color  showing  on  the  walls  of  either  the  fillings  or  the  cavi- 
ties. The  only  exceptions  have  been  where  the  margins  were  rounded, 
as  at  a,  a',  Fig.  303,  and  the  fillings  not  cut  below  them  as  shown,  but 
left  feather-edged,  as  at  d,  d' ,  Fig.  305.  In  these  few  instances  discolor- 
ations  were  found  under  the  laps,  but  in  no  case  extending  farther  than 
to  A',  A',  Fig.  306.  The  tests  prove  that  under  conditions  as  nearly 
practically  parallel  as  extra-oral  tests  can  well  be,  gutta-percha  fillings 
properly  made  will  exclude  external  moisture.  Obviously,  it  is  better 
to  pare  the  filling  below  the  enamel-slopes,  as  in  Figs.  304  and  306, 
than  to  leave  it  overlapping,  as  in  Figs.  303  and  305.  For  a  final  finish 
use  a  rapidly  revolved,  lightly  touching,  cuttlefish-paper  disk,  followed 
by  a  wisp  of  bibulous  paper  or  piece  of  tape  wet  with  chloro-percha, 
applied  for  but  an  instant,  to  glaze  the  surface  of  the  filling. 

"  In  the  case  of  a  very  thin  enamel  front  like  that  of  Fig.  292,  that 
part  of  the  cavity  C  may  be  varnished  with  thin  chloro-percha  and  dried 
with  hot  air  just  prior  to  filling  it  as  before  said.  It  might  first  be 
thinly  coated  with  a  tinted  oxyphosphate  or  oxychlorid  of  zinc,  which 


318  PLASTIC  FILLING  MATERIALS. 

should  be  given  ample  time  to  liardcn  before  placing  the  giitta-porelia. 
Indeed,  it  is  a  fundamental  feature  of  good  gutta-percha 
Morlv  that  while  one  cann(»t  operate  too  ra])idly  when 
the  plastic  i.s  at  its  proper  temperature,  the  preparatory 
and  completing  processes  should  be  given  as  much  time, 
care,  and  close  scrutiny  as  more  elaborate  and  often  less 
enduring  gold  operations.  There  is  furthermore  room 
for  the  exercise  of  the  artistic  faculty  in  having  at  hand  chloro-percha, 
or  cellulose  varnish  of  varied  colors,  with  which,  by  means  of  a  small 
brush,  a  gutta-percha  filling  as  B,  Fig.  294,  and  one  in  the  like  cavity 
C,  may  be  given  an  inconspicuous  shade,  and  the  painting  be  renewed 
from  time  to  time,  if  that  be  necessary  by  reason  of  wear.  Fig.  307  is 
a  sectional  view  of  fillings  like  B,  C,  Fig.  294." 

Finishing-  Gutta-percha  Fillings. —  If  a  gutta-percha  filling  has 
been  packed  with  the  proper  amount  of  care  and  skill,  it  should  require 
but  little  trimming.  It  should  be  undisturbed  until  cold.  Its  harden- 
ino;  mav  be  hastened  and  intensified  bv  holdiny-  ice-water  in  contact 
with  it  for  a  few  moments. 

The  portions  overlying  the  margins  are  to  be  trimmed  with  extremely 
sharp  lancets  or  by  warm  blades.  Every  cut  should  remove  a  little  of 
the  surplus  material,  never  a  mass  of  it,  and  should  be  made  toward  the 
cavity  margins,  never  away  from  them.  The  filling  should  have  been 
made  so  that  no  fulness  is  present  to  require  reducing. 

It  is  a  general  practice  to  give  a  smooth  face  to  a  gutta-percha  filling 
by  wiping  it  with  a  tape  slightly  moistened,  not  wet,  with  chloroform. 
The  surflice  produced  by  this  means,  although  smooth,  does  not  retain  its 
integrity  so  well  as  when  the  surface  is  formed  by  cutting. 

The  use  of  gutta-percha  as  a  canal  filling  is  discussed  in  Chap.  XVII. 

Basic  Zinc  Cements. 

Zinc  Oxychlorid. — The  basic  zinc  cements  employed  in  dentistry  are 
the  oxychlorid  and  the  phosphate ;  the  oxysnlfate  should  also  be  included. 

The  oxychlorid  is  formed  ])y  the  combination  of  calcined  and  pul- 
verized zinc  oxid  with  a  solution  of  zinc  chlorid  : 

ZnO  +  ZnCl^  +  H.,0  =  2ZnClHO. 

This  compound  was  introduced  as  a  dental  filling  material  about  1850, 
its  hardness,  whiteness,  and  apparent  insolubility  recommending  it  for 
that  purpose.  It  required  no  lengthy  ])eriod  of  time  to  demonstrate 
that  as  a  filling  material  per  se  it  was  unfit  for  use.  It  disintegrated 
rapidly  and  was  not  free  from  shrinkage. 

Propekties. — Freshly  mixed,  this  material  is  irritating  to  vital 
tissues  with  which  it  is  brought  in  contact ;  applied  close  to  or  upon  an 
exposed  pulp  it  may  be  productive  of  a  transient  or  a  persistent  irritation, 


BASIC  ZINC  CEMENTS.  319 

or  even  inflammation.  The  extent  of  the  irritation  is  largely  governed 
by  the  fluidity  of  the  cement  paste,  i.  e.  the  amount  of  ziuc  chlorid  present. 

It  sets  in  fifteen  minutes  sufficiently  to  permit  the  packing  upon  it 
of  an  amalgam,  and  in  half  an  hour  a  gold  filling.  After  setting  it  is 
whiter  though  less  hard  than  the  zinc  phosphate ;  it  shrinks,  particularly 
when  used  in  large  masses.  It  is  a  poor  thermal  conductor,  and,  like 
all  bodies  containing  zinc  oxid,  is  soluble  in  lactic  acid — the  usual  sol- 
vent in  the  oral  cavity.  These  several  features  are  at  present  regarded 
as  limiting  the  application  of  oxychlorid  to — first,  a  lining  material  for 
carious  cavities  over  which  the  insoluble  filling  proper  is  to  be  placed ; 
second,  as  a  root-filling  material  (its  use  in  this  connection  is  discussed 
in  Chapter  XVII.).  It  is  to  be  noted  that  the  cement  retains  after 
setting  an  antiseptic  power  for  a  greater  or  less  period. 

Use. — Zinc  oxychlorid  is  usually  employed  as  a  lining  material  in 
teeth  having  what  is  known  as  poor  structure — those  in  which  caries 
proceeds  to  great  depths  without  external  evidence  of  the  extent  of 
invasion.  After  these  cavities  have  been  partially  excavated  it  is  found 
that  further  excavation  and  the  removal  of  the  deepest  layers  of  the 
leathery  dentin  which  appear  to  have  retained  sensitivity  would  prob- 
ably uncover  the  pulp ;  it  may  be  that  the  pulp  has  given  subjective 
evidence  of  a  mild  attack  of  active  hyperemia. 

In  such  cases  the  deepest  layer  of  the  partially  disorganized  dentin 
is  permitted  to  remain  and  is  subjected  to  the  prolonged — fifteen  minutes 
or  longer — contact  of  hydrogen  peroxid  in  the  25  per  cent,  ethereal 
solution  (caustic  pyrozone),  5  per  cent,  aqueous  solution  of  formalin, 
or  preferably  a  saturated  solution  of  thymol  in  alcohol.  The  cavity 
walls  are  well  dried  with  bibulous  paper  and  the  warm-air  blast. 
Upon  a  mixing  slab  (see  Fig.  308),  a  drop  or  two  of  the  zinc  chlorid 
is  placed,  and  beside  it  a  quantity  of  the  zinc  oxid  powder.  The 
powder  is  gradually  incorporated  with  the  fluid  by  means  of  a  spatula 
until  a  creamy  paste  is  made.  A  number  of  balls  of  bibulous  paper 
are  to  be  at  hand.  A  portion  of  the  paste  is  taken  upon  the  end  of 
an  instrument  and  placed  in  the  cavity,  where  it  is  quickly  pressed  into 
a  layer  against  the  cavity  walls  by  means  of  the  balls  of  bibulous  paper. 
The  walls  are  to  be  covered  to  a  uniform  depth  of  about  one-sixteenth 
of  an  inch.  The  prompt  application  of  the  bibulous  paper  usually  pre- 
vents any  irritation  due  to  the  contact  of  the  oxychlorid  with  the  dentin 
overlying  the  pulp.  Should  the  cavity  be  very  deep  it  is  advisable  to 
protect  the  pulp  by  interposing  a  film  of  ethereal  varnish  between  the 
oxychlorid  and  the  dentin  over  the  pulp. 

At  the  completion  of  the  lining  operation,  the  margins  of  the  cavities 
are  to  be  cleansed  of  the  oxychlorid  and  the  filling  completed  with  the 
material  indicated. 


320  PLASTIC  FILLING  MATERIALS. 

Zinc  oxyclilorid  as  an  obtiuuling  atjent  in  tlic  trcatiiiont  of  liyjH'r- 
scnsitive  dentin  is  of  considerable  valno,  and  its  nse  f»>i'  that  jjiirpose  is 
described  in  Chapter  VI. 

The  nse  of  zinc  oxychlorid  as  a  canal  tilling,  and  the  mode  of  nsing 
it,  are  discussed  in  Chapter  XVII. 

T\\t}  poirdcr  of  this  cement  is  made  of  zinc  oxid  cah-ined  and  ])o\v- 
dered,  to  wiiicli  have  been  added  substances  (borax,  silica,  etc.)  Nvhich 
aifect  its  properties  but  little  if  at  all. 

T\w  Jiuid  is  made  by  dissolving  ])ure  zinc  or  its  oxid  in  hydrochloric 
acid  to  the  point  of  saturation  ;  or,  by  making  a  solution  of  zinc  chlorid 
4  parts,  water  3  parts,  and  filtering  the  solution. 

The  use  and  eifects  of  zinc  oxychlorid  as  a  pulp  capping  are  dis- 
cussed in  Chapter  XVI. 

Zinc  Phosphate. — These  cements  are  nominally  a  combination  of 
calcined  zinc  oxid  with  a  syrupy  solution  of  orthophosphoric  acid  : 

3ZnO  +  2H3PO,  =  Zn3(PO,)2  +  3H.O, 

although  their  actual  composition  is  more  variable  than  that  of  any  other 
tilling  material.  Both  base  and  solvent  commonly  contain  impurities — 
those  of  the  base  owing  to  lack  of  discrimination,  or  worse,  in  the  source 
of  the  oxid.  Many  of  the  impurities  of  the  ])h()sphoric  acid  are  due 
primarily  to  the  well-known  inconstancy  of  the  acid  itself,  and  others  to 
the  mode  of  its  manufacture. 

IMany  of  the  specimens  of  powder  are  prepared  from  commercial 
metallic  zinc,  and  therefore  contain  the  impurities  of  that  metal. 
Among  the  latter  is  arsenic,  so  that  the  presence  of  arsenic  compounds 
in  inferior  cement  powders  is  by  no  means  impossible,  which  may  pos- 
sibly explain  in  some  cases  the  death  of  non-exposed  pulps  in  teeth 
which  have  been  filled  with  zinc  phosphate ;  but  as  recent  chemical  in- 
vestigation has  shown  that  the  arsenic  when  present  in  cement  powders 
is  in  the  form  of  an  insoluble  zinc  arsenite,  the  danger  of  arsenical  irrita- 
tion of  the  pulp  from  that  source  would  seem  to  be  a  remote  one. 

A  common  source  of  the  glacial  phosphoric  (metaphosphoric)  acid  of 
commerce  is  from  sodium  phosphate,  variable  quantities  of  which  are 
retained  in  the  acid  solution  as  acid  sodium  phosphate  (dihydrogen 
sodium  phosphate).  This  substance  is  soluble  in  water,  and  must  there- 
fore greatly  increase  the  solubility  of  any  cement  containing  it. 

To  properly  make  pure  specimens  of  zinc  oxid  and  phosjihoric  acid 
is  a  comparatively  expensive  operation — which  will  serve  to  explain  the 
seemingly  high  cost  of  fine  specimens  of  cement,  and  incidentally  serve 
as  a  warning  against  the  indiscriminate  use  of  cheap  cements. 

Making  the  Powder. — A  quantity  of  pure  zinc  oxid  is  luted  in  a 


BASTC  ZINC  CEMENTS.  321 

sand  crucible  and  kept  at  the  highest  forge-heat  for  hours.  When  cool 
the  crucible  is  broken  away  and  the  vitreous  mass  of  yellowish  zinc  oxid 
is  reduced  to  a  powder  which  will  pass  through  a  fine  bolting  cloth. 
This  powder  is  placed  in  tightly  stoppered  bottles,  for  if  exposed  to  the 
air  it  absorbs  carbon  dioxid  and  a  portion  of  it  is  converted  into  the 
hydrated  carbonate  of  zinc.  This  change  may  be  noted  in  old  powders 
by  the  efferve'scence  due  to  the  disengagement  of  carbonic  oxid  when 
phosphoric  acid  is  added  to  them.  Numerous  substances  have  been 
added  to  the  basal  powder  with  the  object  of  lessening  the  disintegra- 
tion, i.  e.  chemical  solution,  when  used  as  a  dental  cement.  Usually 
these  additions  are  the  oxids  of  other  metals.  The  oxid  of  magnesium 
added  to  the  powders  causes  the  cement  to  set  more  rapidly  ;  the  oxid  of 
aluminum  increases  the  rapidity  of  setting  and  makes  a  finer-grained 
cement,  the  central  texture  of  which  is,  however,  inferior.  Cements  of 
zinc  oxid  and  phosphoric  acid  alone  are  apparently  less  soluble  in  lactic 
acid  than  when  the  oxids  of  aluminum  and  magnesium  are  added. 

Various  other  substances  have  been  added  which  do  not  enter  into 
chemical  combination  with  the  phosphoric  acid,  in  the  hope  of  confer- 
ring greater  durability  on  the  cement,  but  as  yet  but  few  of  them  have 
been  shown  to  possess  any  value. 

The  Fluid. — Phosphoric  acid  in  its  pure  state  is  formed  by  hydrating 
phosphorus  pentoxid : 

PA  +  3H20  =  2H3PO,. 

Much  of  the  phosphoric  acid  used  for  cements  is  made  by  hydrating 
the  glacial  (metaphosphoric)  acid,  HPO3.  The  acid  dissolves  readily 
in  water,  being  deliquescent  when  pure.  Difficulty  of  solution  is 
therefore  an  indication  of  impurity  of  the  glacial  acid.  It  requires  a 
definite  degree  of  heat  to  bring  about  the  chemical  hydration  of  the 
acid.  At  a  temperature  of  210°  F.  the  union  occurs,  which  is  attended 
by  the  evolution  of  heat,  the  glacial  acid  being  transformed  into  ortho- 
phosphoric  acid.  These  acids  are  all  hygroscopic.  They  will  even  ab- 
stract water  from  sulfuric  acid. 

Impurities. — The  commercial  glacial  acid  is  commonly,  or  as  a  rule, 
impure,  containing  variable  amounts  of  sodium  and  magnesium  phos- 
phates. These  salts,  particularly  the  dihydrogen  (acid)  sodium  phos- 
phate, are  permanently  soluble  in  the  phosphoric  acid,  and  therefore 
give  no  evidence  of  their  presence  by  the  formation  of  precipitates. 
They  are  also  soluble  in  water,  w^hich  fact  has  a  direct  bearing  upon  the 
durability  of  cements  made  with  the  impure  acid. 

It  has  been  stated  by  writers  that  the  acids  of  cement  were  occasion- 
ally the  meta-  and  pyrophosphoric.  A  test  of  some  of  them  said  to  be 
21 


n22  PLASTIC  FfLLLWG  MATERIALS. 

of  these  varieties  sliowcd  none  of  them  to  ^ive  tlie  reaction  of  the  pvro- 
acid  ;  a  few  givinji^  traees  of  the  nieta-  acid. 

Preeij)itates  whieh  form  in  cement  fluids  are  prohahly  metallic  ])hos- 
phates.  The  instability  of  cement  fluids  is  notorious.  Asi<le  from  the 
known  or  probable  contaminations  which  they  may  contain  this  insta- 
bility is  to  be  regarded  as  a  distinctive  feature  of  ])hosplioric  acid. 

The  Cement. — To  make  the  cemoif,  successive  portions  of  the  oxid 
are  mechanically  incorporated  with  the  iluid  until  a  stilT  paste  results. 
In  five  minutes  a  l)all  made  of  the  paste  j^lazcs,  and  rebounds  when 
dropped  upon  a  hard  surface.  It  breaks  with  a  granular  surface  ;  in 
fifteen  minutes  it  is  cut  with  some  difliculty.  If  the  cement  fluid  con- 
tain the  acid  sodium  phosphate,  an  acid  reaction  may  remain  for  hours 
or  days.  The  atmospheric  conditions  markedly  modify  tlu'  properties. 
In  warm,  or  hot  and  moist  weather,  the  setting  is  more  rapid  and  it 
may  be  sudden.  In  cold  weather  it  is  delayed.  The  greater  the  dilu- 
tion (the  thinner  the  fluid),  the  more  rapid  the  setting. 

In  its  freshly  mixed  state  zinc  phosphate  is  adhesive,  losing  this 
pro})erty  in  a  great  degree  when  set,  if  surrounded  by  moisture.  It  has 
a  higher  rate  of  heat  conductivity  than  zinc  oxychlorid. 

Uses. — Its  legitimate  field  of  usefulness  is  in  situations  and  under 
conditions  where  its  advantageous  properties  may  be  utilized  and  its 
disadvantages  minimized.  One  of  the  priucij)al  f  u-ts  to  be  borne  in 
mind  is  the  solubility  of  the  cement  in  lactic  acid,  which  is  present 
almost  always  about  the  necks  of  the  teeth,  in  approximal  spaces,  and 
along  gingival  margins.  Its  clinical  use  is  therefore  attended  by  the 
greatest  measure  of  success  when  placed  at  a  distance  from  such  situa- 
tions— as,  for  example,  in  cavities  opening  upon  the  masticating  sur- 
faces of  teeth,  where  its  great  hardness  is  an  element  of  advantage. 
Good  specimens  have  been  known  to  last  for  periods  varying  from 
three  to  eight  years.  Dr.  Henry  Weston  has  cited  cases  where  an  un- 
usually good  zinc  phosphate  filling  has  lasted  for  ten  years. 

As  a  filling  material  per  se,  zinc  phosphate  has  but  limited  employ- 
ment except  for  the  teeth  of  children,  and  as  a  temporary  filling  in  the 
teeth  of  adults.  Times  and  occasions  will  suggest  themselves  to  every 
operator  where  gold,  amalgam,  and  gutta-percha  are  contraindicated  as 
filling  materials  ;  in  such  cases  zinc  phosphate  performs  a  useful  ser- 
vice. Its  great  field  of  usefulness — where,  indeed,  there  is  no  substi- 
tute for  it — is  in  the  filling  of  the  greater  portion  of  extensive  cavities, 
which  are  then  filled  and  sealed  with  gold  or  amalgam,  by  an  inlay,  or  it 
may  be  by  a  partial  crow'n.  It  is  invaluable,  and  in  most  cases  indispen- 
sable, as  the  retaining  medium  of  fixed  bridge  work  and  of  many  forms 
of  artificial  crowns. 

Prior  to  placing  the  zinc  phosphate  filling  in  a  cavity,  it  is  a  wise 


BASIC  ZINC  CEMENTS. 


323 


Fig.  309. 


Fig.  311. 


precaution  to  line  the  latter  with  one  of  the  quick-drying  ethereal  var- 
nishes, to  protect  the  dentinal  walls  from  contact  with  acid  sodium 
phosphate  which  may  be  present  in  the  cement.  In  some  cases  the 
placing  of  the  cement  in  proximity  to  a  non-exposed  pulp  is  productive 
of  marked  suifering.  Should  the  cavity 
be  very  deep  it  is  the  usual  practice  to 
place  a  softened  disk  of  gutta-percha 
over  the  wall  nearest  the  pulp.  The 
rubber  dam  should  always  be  adjusted 
before  the  insertion  of  a  phosphate  fill- 
ing, to  insure  dryness. not  only  during 
the  insertion,  but  during  the  period  of 
hardening,  at  least  fifteen  minutes. 

Mixing  of  Cement. — This  is  an 
operation  of  equal,  if  not  greater,  im- 
portance than  any  other  in  the  manipu- 
lation of  zinc  phosphate.  Dr.  Henrj'^ 
Weston  has  demonstrated  how,  almost 
entirely,  the  mixing  of  cement  gov- 
erns its  stability.  Specimens  of  the 
same  powder  and  fluid  mixed  after  dif- 
ferent methods  gave  entirely  diiFerent 
results,  not  only  in  the  appearance  but 
also  in  the  hardness,  texture,  and  solu- 
bility. The  method  of  mixing  set  forth 
is  that  of  the  same  experimenter.  As- 
suming for  illustration  that  an  approx- 
imal  cavity  is  to  receive  a  contour  filling, 

or  a  large  occlusal  cavity  is  to  be  filled, 

p 
Fig.  308.  fs»:5^ 


Dropper. 


Fig.  310. 


Glass  mixing  tablet,  with  rubber  feet. 

or  an  extensive  cavity  is  to  be  three- 
fourths  filled  with  cement : 

A  drop,  or,  where  a  large  mass  of 
cement  is  required,  two  drops  of  fluid  are  placed  upon  a  scrupulously 
clean  glass  (Fig.  308)  by  means  of  the  dropper  shown  in  Fig.  309,  and 


Scoop. 


Spatula. 


324  PLASTIC  FILLING  MATERIALS. 

a  mass  of  powder,  in  groat  a|)|>aR'iit  cxfoss  of  that  rciiuircd,  is  heaped 
at  a  distance  from  it,  taken  from  the  hottlo  hy  the  scoop  (Fig.  .'ilO).  A 
portion  of  the  powder  is  drawn  into  the  fluid  l>y  means  of  a  stout  spatula 
(Fig.  .'^11),  and  stirred  with  a  rotary  movement  until  a  thin  jxiste  is 
made;  another  portion  of  powder  is  then  added  and  is  sh)wly  and  thor- 
oughly incorporated;  mon*  jiowder  is  added  until  the  nuiss  is  as  thick  as 
putty  and  ditficult  to  smear  with  the  heavy  spatula;  the  mass  is  scraped 
together,  taken  from  the  spatula,  and  rolled  between  the  forefinger  and 
thumb,  wliieh  liavo  been  well  scrubbed.  The  mass  is  now  kneaded, 
then  rolled  into  an  oblong  pellet. 

If  for  an  occlusal  cavity  a  piece  al)out  one-fourth  the  size  of  the  cavity 
is  set  in  the  deepest  portion  and  ta})ped  into  perfect  apposition  with  the 
cavity  walls  by  means  of  a  burnisher.  Other  pellets  are  added,  and  the 
process  is  repeated  until  the  cavity  is  exactly  full,  the  l)urnisher  form- 
ing the*  surface  of  the  filling  and  outlining  clearly  every  margin  of  the 
cavity.  The  filling  should  remain  under  rubber  dam  for  at  least  fifteen 
minutes — longer  when  possible.  A  coating  of  ethereal  varnish,  a  solu- 
tion of  gutta-percha  in  chloroform,  or  melted  paraffin  as  suggested  by 
Dr.  Bonwill,  is  applied  to  the  snrfiice  and  the  grinding  of  the  filling 
deferred  for  a  day  or  two.  Should  the  cavity  be  upon  an  approximal 
side  of  a  tooth,  a  matrix  is  to  be  employed  ;  the  most  satisfactory  and 
quickly  adapted  instrument  for  this  purpose  is  one  of  the  composition 
silver  strips  used  for  carrying  polishing  j)owders  (Fig.  312).     A  strip 

Fig.  ;;12. 


I''  !   -liiirj   ^1  ii|i 


as  wide  as  the  length  of  the  tooth  is  to  have  one  end  rolled  upon  itself 
until  it  forms  a  cylinder  more  than  one-sixteenth  of  an  inch  thick  (Fig. 
313,  -.1).    The  strip  is  passed  into  the  next  interdental  space  and  drawn 


Fig.  313. 


through  until  the  cylinder  {A)  rests  firmly  upon  the  teeth;  the  free  end 
is  now  passed  through  the  space  into  which  the  cavity  opens ;  where  it 


BASIC  ZINC  CEMENTS. 


325 


rests  upon  the  lingual  surface  of  the  tooth  it  is  burnished  into  contact 
with  the  edges  of  the  cavity,  forming  walls  to  the  latter  (313,  B).  The 
cement  is  introduced  as  in  the  preceding  case,  and  when  the  cavity  is 
full  the  free  end  of  tke  strip  is  drawn  upon,  compressing  and  round- 
ing the  filling.  Should  the  cement  be  an  adhesive  specimen  or  mixed 
thinner  than  described,  the  surface  of  the  flexible  mat-  Fig.  314. 
rix  is  to  be  faintly  oiled  by  means  of  olive  oil. 

At  the  completion  of  the  operation  the  cement  should 
be  exactly  flush  with  the  margins  except  at  the  labial 
aspect,  and  the  surface  of  the  cement  should  have  such 
smoothness  that  polishing  is  not  necessary.  Cement 
fillings  are  polished  dry  with  the  finest  of  cuttlefish 
disks. 

The  process  of  filling  the  body  of  any  cavity  is  the 
same,  except  when  the  enamel  walls  are  thin  and  frail. 
In  the  latter  case,  where  space  permits,  it  is  preferable 
to  line  the  walls  with  the  oxychlorid  of  zinc,  over  which 
the  phosphate  is  placed.  Before  inserting  a  veneer  fill- 
ing of  gold  or  amalgam,  each  cavity  margin  must  be 
scraped  free  from  cement. 

When  orthodontia  appliances  such  as  rings  or  caps, 
or  prosthetic  appliances,  crowns  and  bridges,  are  to  be 
set  it  is  preferable  to  use  a  cement  prepared  for  that 
purpose,  although  it  is  the  general  practice  to  use  the 
cement  to  which  the  operator  is  accustomed,  mixing  it 
thinner  than  for  filling  purposes.  Wherever  possible, 
it  is  advisable  to  operate  under  rubber  dam,  even  while 
setting  orthodontia  appliances. 

The  tooth  is  cleansed  with  chloroform — as,  for  ex- 
ample, when  a  ring  or  cap  is  set — to  remove  fatty  mat- 
ters, and  a  layer  of  shellac  varnish  applied,  which  is 
then  dried  by  the  air  blast  (chip  blower).  Cement 
paste  is  formed,  of  such  consistence  that  it  will  flow 
readily  and  yet  not  be  watery ;  the  inside  of  the  band 
or  cap  is  filled  with  cement  by  means  of  an  appropriate 
spatula  (Fig.  31 4) ;  a  layer  of  cement  is  placed  on  the 
tooth  where  it  is  to  be  embraced  by  the  band,  which  is 
then  pressed  into  position  and  is  to  remain  without 
disturbance  until  it  is  hard.  The  application  of  bands 
or  ligatures  should  be  deferred  until  the  following  day. 
As  soon  as  the  cement  is  hard  the  surplus  is  cut  away 
and  the  dam  removed.  Pointed  spatula. 


326  PLASTIC  FILLING  MATERIALS. 

Temporary  Stopping. 

Preparations  of  tliis  name  are  eonipouiuls  of  irutta-jirrdin  witli 
various  substances  added  to  lessen  the  tenijierature  of  softenin*;. 

As  procured  from  the  manufacturer  they  are  of  two  varieties,  the 
adhesive  and  the  non-adhesive — or,  to  be  more  precise,  the  h>ss  adhesive. 
The  former  preparations,  the  adhesive,  are  usually  made  of  gutta-percha 
(generally  the  pink  base  plate).  Burgundy  pitch,  white  wax,  and  chalk 
or  zinc  oxid.  In  the  non-adhesive  varieties  the  I5urgundy  })itch  is  omitted. 
The  latter  varieties  are  usually  made  of  a  pink  color,  to  furnish  a  safe- 
guard against  mistaking  a  tilling  of  temporary  sto]>ping  for  one  of  gutta- 
percha. 

As  the  name  implies,  they  are  designed  for  temixtrary  use,  retaining 
dressings  in  teeth,  to  maintain  space  between  teeth  which  have  been 
wedged  apart,  until  the  attendant  pericementitis  subsides  ;  to  press  away 
gum  tissue  overhanging  the  margins  of  a  cavity  ;  to  fill  excavated  cav- 
ities for  a  few  days. 

Unlike  gutta-percha,  most  of  these  preparations  cannot  be  ])crmitted 
to  remain  for  a  prolonged  period  ;  they  usually  become  otfensive,  par- 
ticularly so  when  the  hygiene  of  the  mouth  dt)es  not  receive  proper 
attention.  To  maintain  s})ace  and  press  away  gum  tissue  they  are  used 
as  gutta-percha  ;  their  lower  heat  of  softening  permits  tiieir  application 
close  to  the  pulp  of  a  tooth  without  the  painful  response  associated  with 
placing  hot  gutta-percha  in  the  same  position.  X  prominent  use  of  the 
material  is  the  sealing  of  arsenical  applications  in  teeth. 

As  with  any  other  material,  it  is  necessary,  in  order  to  have  the 
minimum  of  pain,  to  make  the  ap})lication  and  manipulate  the  stopj)ing 
so  that  no  pressure  shall  be  exerted  upon  the  pulp.  Temporary  stop- 
ping is  inferior  to  zinc  phos])hate  for  this  purj)oHe,  as  the  latter  may  be 
flowed  into  a  cavity  and  over  an  arsenical  ai>i)lication  without  causing 
the  slightest  pressure. 

Should  the  cavity  of  decay  extend  to  or  beyond  the  gum,  a  small 
conical  piece  of  the  temporary  st()])ping  shoidd  be  softened  and  packed 
carefully  against  the  cervical  margin  and  gum,  to  act  as  a  guard  to  the 
latter  against  contact  with  the  virulent  irritant  arsenic  trioxid.  The 
arsenical  paste  on  a  minute  pledget  of  cotton  is  laid  upon  the  exposed 
pulp — if  the  latter  be  hypersensitive,  beside  it — and  the  remainder  of 
the  cavity  and  interdental  space  are  filled  with  one  very  soft  piece  of 
temporary  stop])ing. 

Temporary  stopjiing,  in  cones,  has  been  used  as  a  canal  filling  (see 
Cliapter  XVII.)  and  as  a  filling  for  the  bulbous  portion  of  pulp 
chambers. 

Another  important  use  of  the  material  is  the  sealing  of  the  occlusal 
cavities  of  teeth  which  are  under  treatment  for  septic  pericementitis. 


OXYSULFATE  OF  ZINC.  327 

Plugs  of  softened  temporary  stopping  have  been  used  for  the  arrest 
of  alveolar  hemorrhage  ;  also  for  the  temporary  setting  of  artificial 
crowns. 

Lining  Varnishes. 

These  are  solutions  of  various  gums  and  resins  in  alcohol,  chloro- 
form, and  ether,  which  are  employed  to  furnish  a  non-conducting  and 
impermeable  film  to  cover  the  dentinal  walls  of  excavated  cavities. 

The  first,  sandarac  varnish,  is  a  thin  solution  of  sandarac  in  alcohol. 

The  second,  a  solution  of  virgin  rubber  in  chloroform. 

The  third  a  solution  of  hard  Canada  balsam,  copal,  or  daniar  in 
ether. 

Another  is  the  preparation  known  as  Jcristaline,  a  solution  of  trinitro- 
cellulose  in  anhydrous  amyl  acetate. 

Before  lining  a  cavity  with  zinc  oxychlorid,  a  film  of  one  of  these 
varnishes,  the  quick-drying  ones  preferred,  is  applied,  and  when  this  is 
dry  the  cement  may  be  inserted  wdthout  causing  pain.  Varnishes  have 
been  used  to  furnish  an  adhesive  surface  upon  which  to  pack  gutta- 
percha fillings.  It  is  always  advisable  to  varnish  the  walls  of  a  cavity 
which  is  to  receive  a  filling  of  zinc  phosphate,  to  prevent  the  action  of 
any  free  acid  or  acid  salt  upon  the  dentinal  walls. 

Some  of  these  varnishes  are  admirable  non-conductors,  and  serve 
in  that  capacity  under  gold  or  amalgam  fillings  in  a  most  satisfactory 
manner. 

They  may  be  used  to  prevent  the  tooth  discoloration  due  to  the  pres- 
ence of  amalgam,  particularly  of  copper  amalgam. 

Zinc  Oxysulfate. 

What  is  known  as  the  zinc  oxysulfate  in  dental  parlance  is  merely 
a  thin  zinc  oxychlorid  containing  zinc  sulfate.  A  true  zinc  oxy- 
sulfate is  made  by  mixing  a  saturated  solution  of  zinc  sulfate  with 
uncalcined  zinc  oxid.  It  forms  a  white  paste  which  sets  quickly  and 
attains  about  the  hardness  of  an  inferior  plaster-of-Paris. 

It  is  bland  and  unirritating  to  exposed  pulps ;  is  a  non-conductor ; 
is  faintly  and  persistently  astringent.^ 

Its  principal  use  is  as  a  pulp  capping  or  protective.  A  thin  paste  is 
made,  in  which  a  disk  of  paper  is  dipped,  then  quickly  and  accurately 
laid  upon  the  area  of  exposure.  When  hard  (in  a  few  seconds)  a  drop 
of  fresh  thin  paste  is  flowed  over  the  capping.  The  cavity  may  then  be 
lined  with  zinc  phosphate. 

As  a  pulp  protector  from  thermal  shock  it  is  applied  in  a  thin  layer, 
and  over  it  a  lining  of  zinc  phosphate  is  packed. 

'  J.  Foster  Flagg:. 


CHAPTEH    XIV. 
COMBINATION!   FILLINGS. 
By  Dwight  M.  Clapp,  D.  M.  D. 


The  use  of  more  than  one  material  for  filling  a  single  cavity  was 
suggested  by  the  observation  of  the  condition  of  fillings  composed  of 
but  one  material  and  noting  the  effects  of  time  and  use  thereon. 

If  a  large  number  of  amalgam  fillings  in  occlusal  cavities  are  exam- 
ined, many  will  be  found  to  have  imperfect  edges.  One  cause  of  this 
imperfection  is,  undoubtedly,  the  brittle  character  of  amalgam,  in  con- 
sequence of  which  the  edges  have  become  broken.  In  other  words, 
amalgam  as  a  filling  material  lacks  edge  strength.  Its  dark,  sometimes 
almost  black,  color  also  renders  it  very  objectionable,  especially  if  used 
in  conspicuous  positions. 

If  the  same  number  of  gold  fillings  in  occlusal  cavities  are  examined, 
the  edges  will  be  found  in  better  condition  than  was  the  case  with  the 
amalgam.  One  reason  for  this  is,  undoubtedly,  because  gold  is  not 
brittle,  but  possesses  sufficient  edge  strength  to  withstand  the  force 
of  mastication.  Its  color  is  also  less  unsightly  than  that  of  amalgam. 
For  occlusal  cavities,  therefore,  gold  is  regarded  as  the  better  filling 
material. 

If  a  series  of  occluso-approximal  cavities  filled  with  gold  be  studied, 
it  will  be  found  that  the  teeth  are  in  much  better  condition  on  the  oc- 
clusal surface  than  at  the  cervical  borders  of  the  fillings.  Compare  gold 
fillings  with  a  series  of  amalgam  fillings  in  this  same  class  of  cavities, 
and  the  condition  of  the  teeth  will  be  reversed  :  at  least  a  much  larger 
percentage  of  the  teeth  will  be  found  in  good  condition  around  the  ap- 
proximal  portion  of  the  fillings  than  was  the  case  with  the  gold.  Hence, 
the  deduction  is  inevitable  that,  of  these  two  materials,  amalgam  is  the 
better  to  fill  the  cervical  portion  of  approximal  cavities. 

!  The  term  "  combination  ' '  is  adopted  for  the  various  fillings  here  described,  in  which 
more  than  one  material  is  used,  because  it  seems  to  be  the  most  comprehensive.  The 
putting  together  of  different  materials  in  filling  teeth  makes  in  no  sense  a  chemical  combi- 
nation, in  which  "any  part  of  the  compound  is  the  same  as  any  other  part  of  it." 
Strictly  speaking,  the  fillings  are  more  "mixtures"  than  "  combinations."  According  to 
the  best  authorities,  however,  the  meaning  given  to  combination  makes  its  use  here  quite 
admissible. 

329 


^-^0  COMBINATION  FILLINGS. 

Zinr  phosphate  ot'inout  has  many  a(hiiirahh'  (|iialiti('s  aiul  is  one  of 
tlie  uu)st  vahial)k'  filling  materials  known.  It  is  easily  worked,  its  color 
is  good,  its  adhesiveness  serves  to  Mnd  tooth  and  tilling  together  as  the 
stonemason's  cement  unites  the  blocks  of  graniti'  that  he  piles  one  on 
the  other  into  one  solid  piece  of  masonry.  As  a  tooth-saver  it  has  no 
equal ;  but  its  one  great  defect,  its  solubility  in  the  fluids  of  the  mouth, 
restricts,  in  a  great  degree,  its  usefulness  when  exposed  to  these  fluids. 

From  this  it  will  be  easily  understood  why  it  is  often  desirable  to 
combine  in  one  filling  two  or  more  different  materials  ;  and  it  may  be 
said  w  ith  truth  that  the  operator  who  selects  his  filling  materials  with 
the  best  judgment,  and  combines  and  uses  them  with  the  most  skill, 
will  save  the  greatest  number  of  teeth.  There  would  be  just  as  much 
common  sense  and  scientitic  reason  for  an  electrician  to  make  a  dynamo 
entirely  of  copper,  or  a  watchmaker  to  use  nothing  but  gold  in  making 
a  watch,  as  for  a  dentist  to  fill  many  of  the  cavities  that  come  to  him 
with  but  one  material. 

It  is  an  error  to  think  that  combination  fillings  are  resorted  to 
because  more  easily  made  than  fillings  of  but  one  material,  or  that  it 
indicates  a  lack  of  skill  on  the  part  of  the  operator  who  makes  and 
recommends  them.  On  the  contrary,  it  is  often  much  more  difficult  to 
make  a  suitable  combination  filling  than  one  of  any  single  material ;  and 
the  student  will  find  that  combination  work  will  give  ample  opportunity 
for  the  employment  of  all  the  skill  and  ingenuity  he  may  possess. 

Every  operation  must  be  made  with  the  greatest  amount  of  care  and 
attention  to  minute  details,  or  the  object  sought  will  be  uuattained,  and 
the  result  be  an  inferior  piece  of  work  which  will  sooner  or  later  cause 
grief  to  the  patient  and  chagrin  to  the  operator. 

It  is  impossible  to  describe  all  the  combination  fillings  that  have 
been  found  advantageous  and  useful,  therefore  only  some  of  the  most 
important  will  be  considered  in  detail.  The  list  is  limited  only  by  the 
perverse  manner  in  which  teeth  decay,  and  by  the  ingenuity  of  the  ope- 
rator to  devise  scientific  and  practical  combinations  to  meet  the  cases 
presenting. 

It  is  to  be  understood  in  every  instance  in  this  chapter  that  the  teeth 
are  in  proper  condition  to  be  filled  without  further  treatment.  If  pulp- 
less,  the  roots  are  supposed  to  have  been  put  in  a  healthy  condition  and 
filled.  In  cases  of  exposed,  or  nearly  exposed,  pulps,  they  are  supposed 
to  have  been  properly  protected,  and  the  teeth  ready  in  every  respect 
for  the  mechanical  operation  of  inserting  the  fillings. 

Cement  (Zinc  Phosphate)  and  Amalgam. 

In  Simple  Cavities. — This  combination  is  of  the  greatest  service  in 
saving  badly  decayed  teeth  that  otherwise  might  have  to  be  cut  off  and 


CEMENT  AND  AMALGAM. 


001 
00 1 


Fig.  315. 


crowned,  or  perhaps  lost  altogether.  The  simplest  cases  where  it  may 
judiciously  be  employed  are  occlusal  cavities.  Many  such  cases  are 
seen  where  there  is  little  left  but  the  enamel,  which,  however,  is  thick 
around  the  orifice  of  the  cavity,  and,  if  properly  supported,  will  have 
sufficient  strength  to  withstand  the  ordinary  strain  of  mastication. 
Great  care  should  be  taken  to  remove  the  decay  from  every  part  of  the 
cavity,  being  sure  that  none  is  left  under  the  cusps  or  any  part  of  the 
overhanging  enamel. 

The  edges  of  the  cavity  must  be  carefully  trimmed,  so  that  the  filling 
can  be  finished  flush  with  the  external  surface,  in  order  not  to  leave  any 
overhanging  portion  of  amalgam  to  be  broken  off,  as  it  certainly  will  be 
if  so  left,  to  the  great  injury  of  the  filling. 

There  are  but  few  cases,  even  in  occlusal  cavities,  where  the  rubber 
dam  should  not  be  used,  at  least  for  the  final  excava- 
tion and  for  putting  in  the  filling ;  for  it  is  almost  im- 
possible to  be  sure  that  all  decay  has  been  removed 
from  a  cavity  unless  it  is  dry,  No  filliug  should  be 
allowed  to  get  wet  before  it  is  all  in  place  if  it  can 
possibly  be  avoided.  It  is  much  better  to  err  by 
using  the  rubber  dam  too  often  than  not  often  enough. 
Fig.  315  shows  a  cavity  such  as  described. 

The  cavity  being  ready,  sufficient  amalgam  to  fill 
one-third  of  it  is  prepared.  Before  introducing  the  amalgam,  however, 
the  cavity  is  filled  two-thirds  or  three-fourths  with  rather  soft  cement, 
into  which  pieces  of  the  prepared  amalgam  are  crowded,  forcing  the 
cement  into  every  portion  of  the  cavity.  The  cement 
which  has  oozed  out  around  the  edges  is  then  removed 
with  an  excavator,  and  the  operation  will  have  the  ap- 
pearance shown  in  Fig.  316.  The  filling  is  then  com- 
pleted in  the  same  manner  as  an  ordinary  filling  of 
amalgam  in  an  occlusal  cavity. 

The  advantages  of  this  kind  of  filling  are  many  :  The 
bulk  of  it  is  of  cement,  which  does  not  change  its  shape 
perceptibly  and  is  the  best  of  materials  when  not  ex- 
posed to  the  fluids  of  the  mouth.  The  cement  firmly 
unites  the  tooth  to  the  filling,  thus  making  a  support  to 
the  frail  walls  as  well  as  a  stopping  to  the  cavity.  The 
amount  of  metal  is  reduced  to  just  enough  for  a  cover- 
ing of  sufficient  strength  to  guard  the  cement,  and  the  tooth  will  not  be 
discolored  by  the  amalgam,  as  is  often  the  case  in  teeth  of  not  very 
dense  structure,  and  especially  in  the  mouths  of  young  patients,  when 
not  thus  protected. 

The  combination  of  cement  and  amalgam,  as  described  above  for 


Large  occlusal 
cavity. 


Fig.  316. 


Section  showing 
amalgam  and 
cement.  (Sur- 
plus cement 
must  now  be 
removed;  then 
finish  with 
1.) 


332  COMBINATION  FILLINGS. 

occlusal  cavities,  may  l>o  used  in  the  same  manner  in  simple  approxinial 
cavities  in  the  molars  and  bicuspids,  and  even  in  tiie  six  front  teeth, 
when  the  cavities  are  so  situated  that  the  amalg:am  does  not  show. 
When  used  in  the  front  teeth  the  cement  should  be  allowed  to  remain 
very  near  to  the  edges  of  the  cavity.  The  amalgam  need  not  be 
more    in    amount    at    this    point    than    the   thickness    of  an    ordinary 

Fig.  .S17. 


Cement  and  amalgam  filling  in  an  incisor.    The  surplus  cement  has  been  removed  and  the  fill- 
ing is  now  ready  for  the  finishing  portions  of  amalgam  :  a,  enamel ;  b,  cement ;  c,  amalgam. 

visiting  card  (see  Fig.  317).  For  the  front  teeth  very  light  colored 
amalgam  should  be  selected,  as  color  is  of  more  importance  than 
strength. 

In  the  temporary  molars  this  combination  can  be  used,  frequently, 
with  the  greatest  satisfaction,  especially  in  those  shallow  approximal 
cavities  where  but  little  undercut  can  be  obtained  without  exposing  the 
pulp.  The  cement  should  be  used  quite  thin,  and  the  amalgam  worked 
into  it  with  a  burnisher,  or  rounded  instrument,  forcing  the  cement  to 
a  feather  edge  at  the  margins  of  the  cavity.  In  cases  of  this  kind  resto- 
ration of  contour  should  not  be  attempted,  as  the  force  of  mastication 
might  serve  to  fracture  the  cement  and  dislodge  the  filling.  In  this 
manner  many  troublesome  and  difficult  cavities  can  be  successfully 
treated,  and  teeth  made  to  last  their  allotted  time  that  would  otherwise 
be  prematurely  lost. 

In  Compound  Cavities. — A  more  extended  description  will  be 
necessary  for  the  treatment  of  compound  cavities  in  the  bicuspids  and 
molars,  especially  where  it  is  desirable  to  restore  contour.  In  these 
cases  a  matrix  is  often  a  necessity.  There  are  niaiiy  matrices  that  may 
be  used  successfully,  but,  as  they  are  described  in  otiier  parts  of  this 
work,  only  one  need  be  mentioned  here.  This  is  selected  on  account  of 
being  almost  universal  in  its  application.  It  can  be  made  from  any 
metal  not  acted  on  by  the  mercury  contained  in  amalgam,  (jerman 
silver  is  inexpensive  and  seems  to  meet  every  requirement,  and  is, 
therefore,  recommended.  For  ordinary  use  it  should  be  from  No.  35  to 
No.  38  gauge.  If  stiff  it  should  be  annealed,  so  as  to  be  readily  bent  to 
the  form  of  the  tooth.     It  can  l)e  easily  polished  so  as  to  reflect  light 


CEMENT  AND  AMALGAM. 


333 


into  the  cavity,  by  drawing  a  narrow  strip  of  it  between  two  pieces  of 
stationer's  rubber  (ink  erasers).  Place  one  piece  of  the  rubber  on  a 
table,  then  the  strip  of  metal  held  with  pliers  in  one  hand  is  placed  on 
the  cake  of  rubber,  while  with  the  other  hand  another  piece  of  rubber 
is  held  firmly  down  on  the  metal,  which  is  drawn  between  the  two  until 
sufficiently  bright. 

For  ordinary  cases,  a  piece  is  cut  from  the  German  silver,  as  shown 
in  Fig.  318,  A,  wide  enough  to  extend  from  the  top  of  the  tooth  to  a 
little  beyond  the  cervical  wall  of  the  cavity,  and  long  enough  to  a  little 
more  than  cover  the  cavity  laterally  when  tied  in  place.  Sometimes  it 
is  necessary  to  make  the  matrix  with  a  lip  to  extend  under  the  gum,  as 
shown  in  Fig.  318,  B,  or  in  some  other  irregular  form,  so  that  it  can  be 


Fig.  318. 


A,  Matrix  and  ligature ;  B,  lipped  matrix. 

made  to  properly  fit  the  cavity.  Special  cases  may  require  a  very  wide 
or  a  very  narrow  one.  The  operator's  ingenuity  must  devise  the  right 
shape. 

For  tying  the  matrix  to  the  tooth,  coarse,  well- waxed  floss  silk  is  the 
best.  It  is  passed  through  the  holes  punched  in  the  metal,  as  shown 
in  Fig.  318,  A  and  B.  When  these  holes  are  made,  the  edges  must  be 
finished  smooth,  or  the  silk  will  be  cut  when  drawn  tightly  around  the 

tooth.     The  operator  must  use  tact  as  to 
Fig.  319.  how  and  where   to    make    his    knots    in 

tying  on  the  matrix.  Usually,  a  good 
way  is  to  place  one  end  of  the  ligature,  a, 
between  the  teeth,  then  to  make  a  sur- 
geon's knot,  as  shown  in  Fig.  319.  The 
other  end  of  the  ligature,  h,  is  then  forced 
between  the  teeth,  and  the  knot  tightened. 
This  will  bring  the  knot  between  the 
teeth  and  opposite  the  matrix  and  will  hold  the  latter  until  it  can  be 
shaped  and  bent  into  place  with  a  burnisher  or  other  suitable  instru- 
ment. The  knot  is  again  tightened,  and  the  two  ends  of  the  ligature 
carried  to  the  back  of  the  matrix  and  a  similar  knot  tied  there.  The 
second  knot,  when  drawn  tightly  against  the  back  of  the  matrix,  forces 
it  closely  up  to  the  cervical  border  of  the  cavity,  and  makes  a  firm 
resistance  when  the  filling  is  being  condensed.     The  silk  is  then  wound 


Manner  of  ligating  the  matrix. 


334  coMniNA Tioy  II I. r ixns. 

round  and  nmnd  tlic  tooth  and  matrix  until  it  nearly  coviM's  both,  or  at 
least  sntticicntly  to  insure  its  remaininsj  in  j)lac('  diirini;  the  o]>eration. 
A  knot  may  he  tied  each  time  the  silk  is  wound  around  the  tooth,  or 
not,  as  aj)|)ears  to  he  necessary.  Sometimes,  when  the  sides  of  the 
tooth  are  slo))inij,  the  lijj^ature  has  a  tendency  to  sli]i  off.  This  can 
usuallv  he  ovei'come  hv  turninii;  hack,  with  tweezers,  the  two  u|)]K'r 
corners,  as  shown  in  Fijj^.  324.  To  saturate  the  lisj^ature  with  saudarac 
or  other  sticky  varnish  will  sometimes  he  sufficient  to  j)revent  the  same 
tendency. 

Fig.  320  illustrates  a  simple  and  ch-licate,  hut  very  powerful,  little 
Pjj.  ;^oo  i^l'P  matrix  which  is  of  great  efficiency 

^ ^  ^ — ^   ^ — ^     ^ — v,,^       in   the  treatment  of  occluso-approximal 

-.p^    ^-  ■     I,       ^^^       cavities.  They  were  conceived  originally 

K^J  ^      1  (^     J    y^^^J      f^r  tlic  plastics,  in  which  case  they  are 

left  iu  place  over  night  (tiie  plastics  thus 
settins^  under  pressure),  slipping  out  easily  the  next  day  away  from  the 
then  hardened  and  perfectly  contoured  surface  of  the  filling. 

"  Thev  are  most  easily  made,  even  for  each  case  (though  in  practice 
this  is  not  necessary,  as  they  may  he  employed  over  and  over  again), 
as  follows:  Suitable-shaped  pieces,  of  a  size  to  a  little  more  than  over- 
lap the  cavity  margins,  are  cut  from  thin  .  .  .  steel,  .  .  .  all  corners 
and  burred  edges  smoothly  finished  ;  a  tiny  hole  is  punched  close  to 
the  middle  of  both  the  buccal  and  lingual  edges,  and  it  is  then  laid 
upon  a  piece  of  lead  and  swaged  (not  merely  bent,  be  it  remarked)  into 
perfect  concavity,  greater  or  less  as  the  individual  case  shall  require, 
bv  tapping  with  a  hammer  a  convex  rod  of  hardened  steel  laid  upon  it; 
mv  own  instrument  being  a  round-headed  picture  nail,  case-hardened, 
])olishcd,  and  with  twisted  wire  attached  at  right  angles  to  a  handle. 
Any  amount  or  shape  of  concavity  required  for  each  case  can  thus  be 
produced  in  a  monient,  cither  newly  from  blanks  kept  ready  or  changes 
made  in  those  used  for  other  cases  to  fit  the  one  in  hand,  about  a 
dozen  of  different  sizes  and' degrees  of  convexity  being  sufficient  to 
select  from,  with  little  or  no  changes  for  all  ordinary  cases.  The 
tapping  having  re-stiffened  the  steel  somewhat,  taken  in  connection 
with  the  impingement  of  the  convex  face  against  the  apj)roximal 
surface  of  the  adjoining  tooth,  gives  firmness  and  strength  to  these 
delicate  little  strips  and  a  perfect  hugging  fit  to  the  surfaces  of  the 
tooth  being  filled,  especially  at  its  cervical  margin,  that  is  most 
satisfactory."  ' 

When  the  cavity  involves  a  large  portion  of  the  crown,  or  the  mesial 
and  distal  surfaces,  the  matrix  should  be  long  enough  to  almost  encircle 

'  Denial  Cosmos,  .June    1898,  vol.  xl.  Xo.  6,  p.  452. 


CEMENT  AND  AMALGAM. 


335 


Fig.  321. 


Fig,  .S22. 


Matrix  with  marginal  slits. 


the  too^h,  the  ends  nearly  joining  against  the  sound  remaining  wall  (see 
Fig.  321).  In  such  cases  it  may  be  desirable  to  slit  it  one  or  more 
times,  in  order  that  it  may  be  made  to  take  the  form  of 
the  tooth  more  easily  (Fig.  322). 

After  the  tying  is  completed,  a  suitably  shaped  bur- 
nisher is  used  to  form  the  matrix,  by  pressing  it  outward, 
to  a  proper  contour. 

One  of  the  desirable  features  of  the  matrix  here  de- 
scribed is  the  ease  with  which  it  is  made  to  give  just  the 
right  shape  and  contour  to  the  filling.  When  used  for 
gold  fillings  it  yields  enough  so  that  with  a  little  care  in 
packing  the  gold  can  be  forced  beyond  the  margin  of  the  cavity  suf- 
ficiently to  insure  a  flush  filling  when  burnished,  after  removing  the 
matrix. 

A  matrix  put  on  as  described  will  have  sufficient  resistance  for  a  gold 
filling ;  for  amalgam,  cement,  or  gutta-percha  it 
may  not  be  necessary  to  tie  it  quite  so  securely. 

For  compound  fillings  of  cement  and  amalgam 
two  methods,  A  and  B,  are  here  given. 

A.  Those  cavities  which,  although  large  and 
involving  much  of  the  tooth,  may  have  but  small  or  comparatively  small 
openings,  especially  if  a  matrix  be  used — and  there  are  but  few  cases 
where  the  matrix  is  not  advisable.  If,  after  putting  on  the  matrix,  in 
this  class  of  cavities,  cement  is  introduced,  and  pieces  of  amalgam 
thrust  into  it,  the  cement  will  most  likely  be  carried  to  the  margin  of 
the  cavity  at  the  cervical  wall,  and  it  will  be  found,  after  removing  the 
matrix  and  finishing  the  filling,  that  a  part  of  the  external  portion  is 
of  cement,  and  not  being  protected  by  the  amalgam,  would  be  washed  out. 
To  avoid  this,  a  portion  of  the  filling  is  made  before  the 
matrix  is  put  on.  Cement  is  put  in,  followed  immediately 
by  the  amalgam  as  described  for  "  occlusal  cavities " 
with  the  added  complication  of  the  missing  approximal 
wall.  After  sufficient  amalgam  has  been  put  into  the 
cement  the  portion  of  the  latter  which  may  have  oozed 
out  must  be  carefully  cut  away,  so  as  to  expose  the  entire 
outer  edge  of  the  cavity,  including  the  cervical  wall  (see 
Fig.  323). 

After  this  has  been  done,  the  matrix  may  be  tied  on  and  the  filling 
completed  as  though  it  were  but  a  simple  cavity.  Sometimes  it  is  well 
to  leave  the  matrix  in  place  until  the  amalgam  is  fully  set.  If  this  be 
done,  care  must  be  taken  that  no  sharp  edge  or  corner  of  it  be  left  to 
wound  the  tongue  or  cheek. 


Fig.  323. 


Cement  lining  and 
amalgam. 


336 


COMBINATION  FILLINGS. 


Fu;.  -.VIA. 


Fig.  .'VJo. 


B.  Cavities  with  Idnji-  opcninc/s.  Tlic  nihbcr  tliini  ami  matrix 
having  been  adjusted,  enoup;h  amalgam  is  paeked 
afjdind  the  mairix  to  iurm  a  shell  of  suttieient 
strength  to  make  the  ai)|)ro.\imal  wall  ot"  the 
filling  (see  Fig.  324). 

This  will  leave  a  large  portion  of  the  cavity 
unfilled  as  shown  in  the  figure  ;  in  this  space  is 
placed  cement,  which  is  gently  worked  into  the 
o, Matrix :  h.amnifram  packed     soft    amalgam,   but    with   care   not   to   carry    it 

against  the  matrix;  c,  por-       ,,  i     .       ^i  ^    •  T>    c  i.\  ^    1 

tion  of  cavity  to  he  nearly     through  to  the  matrix.      Before  the  cement  be- 
fiiied  with  cement  and  (in-     oomcs   hard  more   amalgam  is   put  in,  the  sur- 

ished  with  amalgam.  ,  .  ii,i  ^     ^       n    •   ^      ^ 

plus  cement  is  removed,  and  the  whole  finished 
to  look  like  an  entire  amalgam  filling,  while  in  reality  it  is  only  a  shell 
of  amalgam,  perfectly  fitting  the  outside  of  the  cavity,  cemented  into 
place.  If  the  walls  of  the  tooth  are  frail,  the  cement  will  serve  to 
greatly  strengthen  them.  If,  as  some  claim,  large  metal  fillings  alter 
sufficiently  under  changes  of  temperature  to  fracture  frail  walls,  the 
danger  is  bv  this  method  reduced  to  a  minimum,  as  the  amount  of  metal 
is  only  just  sufficient  to  give  requisite  strength. 

There  is  another  class  of  cavities  which  may  be  described  in  this 
connection,  presenting  great  difficulties  in  themselves, 
yet,  with  this  simple  matrix,  they  are  often  easily 
filled.  It  is  those  cases  where  decay  has  reached  the 
alveolar  border  approximally,  and  extended  on  either 
the  buccal  or  lingual  portion  of  the  tooth,  or  both,  in 
such  a  manner  that  the  dam  cannot  be  made  to  stay 
beyond  the  cervical  border  of  the  cavity.  If  a  liga- 
ture is  used,  it  will  draw  into  the  lateral  grooves  of 
decay  and  be  of  no  use  (Fig.  325). 

The  mode  of  treatment  is  as  already  described, 
with  the  exception  that  the  matrix  is  adjusted  before  the  rubber  is  put  on. 
After  the  matrix  is  in  place,  it  is  but  the  work  of  a  moment  to  put  a 
Palmer  clamp  on  to  the  tooth,  and  slip  the  rubber 
dam  over  clamp,  matrix,  and  tooth.  If  the  matrix 
has  been  carefully  fitted  there  will  be  no  trouble  in 
keeping  the  cavity  dry  long  enough  for  any  ordinary 
operation. 

There    are    certain    buccal    cavities,    also,    below 

which  it  is  difficult  to  retain  the   rubber  dam.     A 

very    narrow    matrix,    adjusted    with    ligature    and 

MHtri.x     and     clamp     ^lamp  (Fig.  326),  ovcr  which  the  rubber  is  placed, 

adjusted,  ready  for     ^yiH  often  greatly  simplify  the  operation.     Modifica- 

app^ica  ion  o        e     ^.^^^  ^^    ^^^.^   method  may  also    be   applied  to  the 


a,  Alveolar  line  be- 
yond which  the  lijra- 
tnre  cannot  be  made 
to  stay. 


Via.  326. 


CEMENT  AND   GOLD.  337 

bicuspids,  and  sometimes  even  to  marginal  cavities  in  the  incisors  and 
canines,  with  good  results. 

Cement  and  Gold. 

This  combination  may  be  used,  with  but  slight  modification,  in  the 
same  manner  and  in  the  same  class  of  cases  that  have  been  mentioned 
for  the  use  of  amalgam  and  cement,  cases  under  B  excejated.  The 
cement  is  placed  in  the  cavity,  and,  while  soft,  pieces  of  some  of  the 
so-called  "  plastic "  golds  are  put  into  it,  in  the  same  manner  as  has 
been  described  for  cement  and  amalgam  ;  the  surplus  cement  is  carefully 
cut  away,  and,  after  waiting  for  that  in  the  cavity  to  become 
so  hard  as  not  to  break  or  crumble  under  pressure,  the  pieces  of  gold 
placed  in  the  soft  cement  are  thoroughly  condensed.  For  this  pur- 
pose, de  Trey's  "  Solila  "  Gold,  Steurer's  Plastic  Gold,  White's  Crystal 
Mat  Gold,  and  Watts'  Crystal  Gold  are  recommended.  The  filling 
can  then  be  completed  with  the  same  or  any  kind  of  cohesive  gold. 
Care  must  be  taken  to  place  a  sufficient  amount  of  the  plastic 
gold  into  the  cement  to  make,  when  condensed,  a  solid  foundation 
upon  which  to  build  the  rest  of  the  filling.  If  too  little  gold  has 
been  used,  it  will  "  chop  up "  and  not  make  a  secure  union  with  the 
cement. 

In  some  large  cavities  it  may  be  found  more  convenient,  after  having 
filled  the  approximal  portion  with  the  cement  and  gold,  to  make  a  second 
mix  of  cement  for  the  rest  of  the  cavity,  into  which  the  gold  is  put  as 
before. 

In  some  special  cases  it  may  be  well  to  use  foil  in  this  manner,  but, 
as  a  rule,  the  j)lastic  golds  will  be  found  preferable. 

Too  much  stress  cannot  be  laid  on  the  desirability  of  this  method 
for  frail  teeth,  remembering  always  that  the  cement  is  the  strengthening 
and  supporting  medium.  The  mason  would  not  build  a  bridge  pier  of 
granite  alone,  or  a  house  of  bricks  without  mortar.  However  nicely 
the  blocks  of  granite  or  the  bricks  might  fit  each  other,  it  is  the  cement 
and  the  mortar  that  hold  them  together  as  in  one  piece. 

Especial  attention  is  called  to  this  combination  of  gold  and  cement 
for  the  six  front  teeth.  In  the  teeth  of  young  patients  and  teeth 
of  low-grade  structure  there  are  often  found  large  cavities  which, 
if  filled  with  gold  alone,  will  in  a  few  years,  sometimes  months,  show 
discoloration  around  the  fillings.  Filled  as  above  described,  every 
vestige  of  decay  having  first  been  removed,  a  combination  results  which 
is  the  ideal  preservative  filling  as  fiir  as  present  knowledge  and  facilities 
go.  Pulpless  front  teeth  that  are  much  decayed  can  be  improved  in 
appearance  and  greatly  strengthened  by  this  method.     Fig.  327  shows 


338 


COMBINATION  FILLINGS. 


Fici.  327.     Yui.  328. 


a  cavity  in  a  central  incisor  that  can  he  fiUcd  to  a<lvaiita<:;c  with  cement 
and  gohl.  Fig.  328  .shows  a  cavity  in  a  central 
inci.sor  with  the  pnlp  removed  and  hut  litth?  of 
tiic  crown  remain ing  hnt  the  enameh  The  greater 
part  of  the  cavity  has  been  filled  with  cement  into 
which  pla.'^tic  gold  has  been  put  and  condensed. 
The  tilling  can  be  com[)leted  with  any  cohesive 
gold. 

In  componnd  cavities  in  molars  and  bicuspids, 

o.  a,  Frail  enamel  walls:      '1^^'^  the  cement  and  gold  have  been  pnt  in,  as 
6.  p.i.i  surface  nuuie  by      described  for   cement  and   amalgam    A,  and    the 

plastic  Rold    condensed  .  ,.  i  ,-,    /-   •/  i  i  i 

into  cement.  matrix  adjusted,  soft  joif  can  he  nsed  to  great  a(i- 

vantage  at  the  cervical  portion  of  the  cavities,  as 
elsewhere  described  for  using  soft  and  cohesive  golds. 

Amalgam  and  Gold. 

Gold  may  be  used  in  combination  with  amalgam — A,  by  allowing 
the  amalgam  to  become  hard  before  adding  the  gold  ;  B,  by  adding 
the  gold  while  the  amalgam  is  soft  and  finishing  the  filling  at  one  sitting. 

A.  Allowing  the  amalg-am  to  harden  and  then  adding-  gold  at  a 
subsequent  sitting  will  usually  be  done  in  compound  cavities  in  bicus- 
pids and  molars,  for  the  purpose,  jirincipally,  of  overcoming  the  dark 
appearance  of  the  amalgam.  For  instance,  a  filling  involving  the  oc-clu- 
sal  and  mesial  surfaces  of  an  upper  first  molar  will,  in  many  mouths, 
.show  more  or  less,  and,  if  of  amalgam,  be  dark  and  unsightly.  To 
avoid  this,  the  cavity  may  be  nearly  filled  with  amalgam,  leaving  a 
portion  of  the  occlusal  surface  and  along  the  buccal  Avail  (this  being  the 
part  of  the  filling  most  likely  to  show)  for  completion  with  gold  later. 

The  matrix  should  be  used  as  described  for  cement  and  amalgam 
fillings.  It  is  a  good  plan  to  leave  it  in  place,  when  convenient,  until 
the  amalgam  is  hard.  Before  adding  the  gold,  it  should  be  ascertained 
what  part  of  the  filling  will  show,  and  the  amalgam  trimmed  and  shaped 
so  that  the  gold  may  form  that  portion  of  the  filling  that  will  be  in 
sight.  Fig.  329  shows  a  compound  cavity  in  a  molar  partially  filled  with 
amalgam.  The  amalgam  has  been  left  until  hard  and  the  filling  is  now 
ready  to  be  finished  with  gold.  The  figure  also  shows  the  ceuK'nt 
lining  under  the  amalgam. 

Suitable  retaining  places  must  be  made  in  the  amalgam  to  hold  the 
gold  in  position,  as  there  is  no  union  between  the  two  in  this  case,  as 
there  is  when  gold  is  added  to  unset  amalgam.  The  gold  being  added 
makes  a  filling  much  superior  in  appearance  to  one  entirely  of  amalgam. 
The  gold  will  also  make  a  better  wearing  material  for  the  masticating 
surface,  having  better  edge  strength  than  the  amalgam,  and  therefore 


A3IALGA3I  AND   GOLD. 


339 


being  less  liable  to  be  broken  a\\  ay  from  the  walls  of  the  cavity  by  the 
force  of  mastication,  as  spoken  of  elsewhere. 

Large  amalgam  fillings,  when  it  is  not  necessary  to  have  gold  added 
on  account  of  color,  will  be  greatly  improved  if  a  channel  is  made  with 
a  small  fissure  bur  between  the  amalgam  and  the  enamel,  and  this  care- 
fully filled  with  gold  (Fig.  330). 


Fig.  329. 


Fig.  330. 


Fig.  331. 


Oceluso-approximal  cavity         Amalgam  and  cement  com-         Gold  and  amalgam  com- 


partly  filled  with  amal- 
gam ready  for  completion 
with  gold :  a,  a,  amal- 
gam ;  b,  cem^ent  lining. 


bination  with  channel  cut 
in  occlusal  margin  for  re- 
ception of  gold :  a,  amal- 
gam; 6,  gold;  c,  channel 
burred  out  ready  for  gold, 
shows  also  cement  lining. 


bination  in  incisor:  a, 
amalgam ;  6,  gold. 


All  amalgam  fillings  when  gold  is  intended  to  be  added,  should  be 
put  in  with  soft  cement,  whenever  possible,  as  described  for  "  Cement 
and  Amalgam  "  fillings.  This  will  prevent  much  of  the  discoloration 
from  the  amalgam,  as  well  as  strengthen  the  teeth.  Many  front  teeth 
can  be  saved  and  made  to  look  well  by  filling  with  cement  and  amal- 
gam, as  before  described,  and,  after  the  amalgam  becomes  hard,  cutting 
away  that  portion  which  is  in  sight,  and  filling  with  gold  (Fig.  331). 

B.  Araalgam  and  gold  fillings,  the  gold  being  added  while  the 
amalgam  is  soft.  These  fillings  will  be  indicated,  usually,  in  com- 
pound cavities  of  the  molars,  and  in  the  occluso-distal  and  sometimes 
even  the  mesial  surfaces  of  the  bicuspids.  The  amalgam  will  occupy 
not  more  than  one-quarter  or  one-third  of  the  approximal  portion  of 
the  cavity,  but  sometimes  in  distal  cavities  of  molars  it  may  be  good 
judgment  to  have  as  much  as  three-fourths  of  that  portion  of  the  fill- 
ing, amalgam. 

No  operation  requires  greater  attention  to  detail,  or  more  neatness 
of  execution,  than  where  gold  is  used  in  conjunction  with  soft  amalgam. 
If  chips  of  the  unset  amalgam  are  left  around  the  matrix,  or  in  the  folds 
of  the  rubber,  or  in  any  place  where  they  may  be  caught  up  on  the  disk 
or  finishing  strip  and  rubbed  over  the  surface  of  the  gold  while  the 
filling  is  being  finished,  they  will  give  it  a  coating  of  mercury  and  injure 
the  appearance  of  the  work.  On  the  other  hand,  if  the  method  given  is 
followed  carefully,  no  detail  left  out  of  account,  no  slovenly  manipula- 
tion allowed  to  pass  for  neatness  and  tact  in  handling  the  materials,  the 


^540  COMBTNATIOy  FILLINGS. 

tilling-  can  be  finished  as  soon  as  the  last  piece  of  gold  is  consolidated, 
without  the  least  danger  of  niorourv  coating. 

In  preparing  the  cavity  for  a  tilling  of  this  kind,  almost  no  tootli 
substance  has  to  be  cut  away  simply  to  get  access  to  the  cavity,  to  prop- 
erly start  and  pack  the  filling,  as  is  often  necessary  if  an  entire  gold 
filling  is  to  be  made.  As  a  consequence,  much  valuai)le  tooth  substance 
is  saved,  for,  so  long  as  the  decay  is  removed  and  frail  edge  walls  are 
cut  away,  the  amalgam  can  be  perfectly  packed,  no  matter  how  irregular 
the  surface  to  which  it  is  to  be  adapted.  Of  course,  the  excavation 
must  be  planned  so  that  a  filling  of  proper  contour  can  be  made,  and 
Malls  cut  back  when  bv  so  doing  future  decay  can  be  bettor  guarded 
against.  There  will  be  nianv  cases  ciu'ouritei'ed,  however,  where,  by 
this  method,  much  of  a  tooth  structure  can  be  left,  whereas  if  gold 
were  to  be  used  it  would  be  necessary  to  cut,  often  causing  severe 
pain,  in  order  that  the  ])art  might  be  properly  filled. 

For  the  jnirpose  of  describing  a  simple  combination  filling  of  this 
kind,  a  cavity  involving  the  occlusal  and  distill  surface  of  an  upper  sec- 
ond bicuspid  is  selected  as  an  example.  In  the  first  place,  sufficient 
space  must  be  secured  for  a  filling  of  the  right  e(mtour,  and  to  allow 
for  passing  in  a  very  thin  strij)  for  finishing  the  filling.  It  is  best  to 
secure  this  room  by  previous  wedging.  Space  having  been  secured,  the 
cavity  is  prepared  with  proper  undercuts,  and  the  walls  of  the  approxi- 
raal  ]iart,  to  be  filled  with  gold,  made  at  as  nearly  a  rir/hf  <n\gle  to  the 
matrix  as  possible.  This  is  in  order  to  facilitate  j)acking  the  gold,  it 
being  very  difficult  to  obtain  a  satisfactory  margin  if  the  walls  form  a 
very  acute  angle  with  the  matrix. 

A  matrix  so  adjusted  that  it  will  stand  the  pressure  of  putting  in 
the  filling  without  moving  is  an  absolute  necessity  for  this  combination. 
It  having  been  ])ut  on  as  described  under  the  head  of  "  Cement  and 
Amalgam  "  fillings  (page  333),  enough  amalgam  is  carefully  packed  at 
the  cervical  wall  to  fill  one-fourth  or  one-third  of  that  portion  of  the 
cavity.  It  should  be  thoroughly  consolidated  by  using  properly  shaped 
instruments  and  sufficient  force  to  drive  it  into  every  part  of  the  cav- 
ity. It  is  a  good  plan  to  use  small  pellets  of  bibulous  paper,  forcing 
them  against  the  amalgam  with  medium-sized  instruments.  The  free 
mercury  which  rises  to  the  surface  should  be  carefully  removed.  It  is 
well  to  put  in  considerably  more  amalgam  than  is  to  be  left,  cutting 
out  the  surplus,  which  method  leaves  a  good  surface  upon  which  to 
begin  with  the  gold.  Before  the  gold  is  added,  however,  care  should 
be  taken  to  remove  every  chij)  of  soft  amalgam  from  the  fi)lds  of  the 
dam,  or  any  that  may  be  clinging  to  the  matrix,  or  in  any  position 
where  it  might  be  brought  in  contact  with  the  gold  when  finishing  the 
filling.     These  chips  will  remain  for  a  long  time  soft  enough  to  coat 


AMALGAM  AND   GOLD. 


341 


the  gold  with  mercury  if  rubbed  against  it, 
therefore  they  must  be  disposed  of  or  an 
unsatisfactory  filling  will  be  the  result. 

The  proper  amount  of  amalgam  having 
been  packed  in  the  cavity,  medium-sized 
pieces  of  some  of  the  plastic  golds  before 
referred  to  are  immediately  added.  The 
instruments  used  first  on  the  gold  should  be  as  large  as  the 
cavity  will  accommodate,  as  they  will  break  it  up  less  and 
more  readily  carry  the  piece  where  it  is  wanted.  I  have  found 
smooth  slightly  oval-faced  instruments  very  efficient  for  start- 
ing the  gold  onto  the  amalgam,  after  which  each  piece  of  gold 
should  be  thoroughly  condensed  with  smaller  instruments 

As  soon  as  the  gold  touches  the  amalgam  it  will  absorb 
mercury,  and  sometimes  several  pieces  of  the  gold  will  be 
entirely  amalgamated.  The  surface  of  the  filling  will  be- 
come very  granular,  and  "  chop  up  "  to  a  certain  degree  as 
the  first  pieces  of  gold  are  used,  and  the  instrument  will 
cause  a  peculiar  squeaky  sound  as  it  is  pressed  against  the 
filling.  The  condensation  must  be  very  thorough  at  this 
point  of  the  work,  or  the  filling  will  be  porous  and  the  union 
between  the  amalgam  and  gold  unsatisfactory.  If  the  work 
is  thoroughly  done,  however,  the  filling  will  be  just  as  strong 
at  this  point  as  any  other.  As  piece  after  piece  of  the  plastic 
gold  is  added,  the  mercury  will  soon  cease  to  penetrate  it, 
and  the  surface  become  entirely  gold.  As  soon  as  this  stage 
is  reached,  and  no  more  mercury  is  visible,  any  kind  of  cohe- 
sive gold  can  be  used  for  the  remaining  portion  of  the  filling. 
Fig.  332  presents  some  instruments  that  have  been  found 
especially  useful  in  this  work.  The  gold  may  be  packed 
with  hand  or  mallet  pressure,  or  both. 

After  the  gold  is  all  packed  the  matrix  is  removed,  and 
the  filling  finished  with  sandpaper  disks,  strips,  burs,  and 
stones,  in  the  ordinary  manner.  For  finishing  the  amalgam 
portion  of  the  filling  only  fine  disks  or  strips  should  be  used. 
The  amalgam  being  yet  in  a  granular  condition,  and  not 
thoroughly  hard,  will  be  dragged  from  the  edges  somewhat 
and  made  slightly  imperfect  if  a  coarse  grade  of  sand  or 
emery  paper  be  used. 

The  gold  will  not  break  away  from  a  filling  made  in 
this  manner,  even  if  there  be  no  undercut  in  the  tooth  for 
holding  it ;  the  union  with  the  amalgam  will  be  quite  suf- 
ficient to  retain  it.     The  cavity  must  have  the  proper  shape. 


1 


Gold-pack- 
ing instru- 
ments. 


342  COMlilNATIOX   FIIJJNGS. 

however,  for  lioldiiii;  in  llie  lillintj:  as  a   wlinlc,  the  same  as  if  it  were 
entirely  of  t^old  di-  aiiialtiaiu. 

Cases  mav  ncciir   where   it  docs   not   matter  whether   tiie  amaltjam 

and  <joM  are  firndy  united  or  not  ;  then,  instead  of  pnttino;  the  ])Uistic 

pold  into  the  amal<ram,  soft   foil   may  he  used  airainst  it  in  the  manner 

deserihed  for  the  eond)ination  of ''soft"  and  "eohesive"  jrold.s(pagc  34o). 

Havinji^  be<'onie  familiar  with  the  simplest  form  of  fillings  of  amalgam 

and  gold,  it  will  be  well  now  to  go  a  step  farther,  and  take  up  some  of 

the  complieations  that  eonstantly  occur.     Even  the  small   amount  of 

amalgam  that  is  used  will  sometimes  discolor  a  tooth  slightly,  especially 

if  the  buccal  wall  is  thin  oi-  if  the  tooth  is  not  of  very  dense  structure. 

When  there  is  danger  of  this  discoloration  taking  place,  it  can  be  largely 

prevented  by  placing  a  medium-sized  pellet  or  fold   of 

foil,    known    as    "gilded    platinum,"    against  the  buccal 

wall  of  the  cavity  before  putting  in  the  amalgam.     This 

foil   l)eing  faced  with  j)latintuu,  wliieh  has  but  very  slight 

ailinity  for  mercury,  the  amalgam    can    be    consolidated 

against  it  with  little  danger  of  discoloration  following. 

On  the  mesial  surface  of  bicuspids  and  molars  it  will 

a.  Amalgam;  6,     not  be  cuough,  always,  to  put  the  gold  and  platinum  foil 

gold    extend-     anrjijnst  the   buccal  wall  ;  more  or  less  of  the  proximo- 

ing     on     the         "  ;  .  ,  .  . 

buccal     side     buccal  surface  of  the  filling  being  exposed  to  view — /.  e. 
nearly  to  the     ^^^^  hidden  bv  the  tooth  anterior  to  it— it  would  look  badly 

gum  margin.  -  •' 

if  made  of  amalgam  ;  consequently,  in  these  cases  the 
gold  must  be  carried  to  the  cervical  wall,  as  shown  in  Fig.  333,  the 
amalgam  occupying  a  triangular  space. 


Cement,  Amalgam,  and  Gold. 

There  are  many  teeth  with  very  large  cavities  and 'frail  walls,  that 
can  be  rendered  serviceable  for  years  and  made  to  look  surprisingly 
well  by  the  use  of  this  triple  combination.  For  instance,  a  molar  or 
bicuspid  having  lost  its  pulp  and  a  large  portion  of  its  crown,  and 
occupying  a  conspicuous  position,  presents  to  the  conscientious  dentist  a 
serious  problem.  He  knows  that  if  filled  with  amalgam  it  will  be  an 
eyesore  to  every  one  by  its  unsightliness.  If  filled  with  gold  it  would 
take  hours,  and  exhaust  both  patient  and  operator,  and  there  would  be 
every  probability  of  the  walls  soon  l)reaking  away  and  the  filling  com- 
ing out,  testifying  to  the  j)o()r  judgment  of  the  operator  in  recommend- 
ing such  a  filling  undiT  such  cireumstanees.  If  filled  with  cement  it 
will  have  to  be  refilled  often,  and  with  each  refilling  would  more  than 
likely  be  somewhat  weakened.  The  loss  of  contour  by  the  wasting  away 
of  the  cement  will  allow  the  tooth  to  change  position,  and  its  usefulness 


GUTTA-PERCHA  AND   CEMENT. 


343 


will  gradually  be  lost,  and  the  tooth  sacrificed  because  the  dentist  did 
not  bring  the  requisite  amount  of  knowledge  and  skill  to  his  aid  to 
meet  the  opportunity  oiFered.  It  is  in  saving  such  teeth  as  these  that 
the  reputation  of  the  dental  profession  for  skill  and  usefulness  is  in- 
creased, and  honor  and  gratitude  are  accorded  to  the  men  who  can 
accomplish  it. 

The  method  of  procedure  will  vary  according  to  the  size,  shape,  and 
position  of  the  cavity.  If  small,  a  little  amalgam  can  be  put  into  the 
soft  cement  before  putting  on  the  matrix,  as  described  for  "  Cement  and 
Amalgam  "  A,  the  surplus  cement  removed  from  the  entire  edge  of  the 
cavity,  the  matrix  adjusted,  more  amalgam  put  in,  and  gold  added,  as 
described  for  "  Amalgam  and  Gold." 

In  larger  cavities,  involving  more  of  the  crown,  after  having  filled 
the  approximal  portion  of  the  cavity  with  the  cement,  amalgam,  and 
gold,  cement  should  be  put  in  a  second  time,  into  which  plastic  gold  is 
carried,  and  the  filling  completed  by  building  gold  on  to  that  which  was 
added  to  the  amalgam,  and  joining  it  to  that  which  was  put  into  the 
second  mix  of  cement. 

In  still  larger  cavities,  the  matrix   can  be  put  on  first,  amalgam 

packed  against  it  to  form  the  outer 

shell  of  the  approximal  side,  as 

described     for      "  Cement     and 

Amalgam "    B ;    cement  is  then 

put  into  the  body  of  the  tooth, 

and  into  this  gold  is  pressed  {iiot 

amalgam)   and    afterward  added 

to    until    it  joins    the    amalgam, 

thus     completing     the     metallic 

shell.       From    the   specimen 

shown  in  Fig.  334  the  matrix  has  been  removed 

to  better  show  the  partially  completed  filling. 
It  will  be  seen  that  the  cement  plays  a  very  important  part  in  this 
operation.  It  will  preserve  the  color  of  the  tooth  though  it  may  have 
been  necessary  to  use  a  little  of  the  gilded  platinum,  or  to  have  the 
gold  extend  to  the  cervical  border  of  the  buccal  corner  of  the  cavity 
to  support  and  bind  firmly  together  the  tooth  and  filling,  yet  it  is  pro- 
tected from  external  influences  which  would  destroy  it.  Fig.  335  shows 
section  of  a  filling  of  cement,  amalgam,  and  gold. 


Fig.  334. 


Fig.  335. 


a,  Amalgam  and  gold  to 
form  approximal  shell 
of  filling;  6,  cement 
and  gold  to  which  is 
to  be  added  gold  to 
complete  the  filling. 


a.  Cement ;    6,  amal- 
gam ;  c,  gold. 


Qutta-Percha  and  Cement. 
This  combination  is  extensively  used  for  what  may  be  termed  tem- 
porary work,  in  the  teeth  of  young  patients,  in  teeth  of  poor  quality, 
and  in  badly  decayed  and  frail  teeth. 


344  COMBfXATrOX  FILLIXGS. 

It  is  fj^cncrally  hclicvcd  that  zinc  pliospliatc  will  iidt  last  as  wrll  at, 
or  just  under,  the  <;uiu  niariiin  in  a|)|)i-it\iinai  cavities  as  will  uutta- 
perelia  ;  altliouuli  exceptions  init;lit  l)e  taken  to  such  a  u'cncral  rule.  it 
is  the  eonmion  custom  to  coniWinc  these  materials,  j)lat-inii-  the  uutta- 
percha  at  cervical  mar*jins,  using  the  cement  tor  the  occlusal  and  con- 
tour portions  of  the  tilling. 

There  is  no  (h)ul)t  that  tillings  of  these  materials  last  much  better 
when  inserted  with  considerable  pressure,  tlierebv  condensing  well  and 
making  tliem  solid.  In  accomplishing  this,  the  matrix  is  of  great 
assistance.  It  not  only  allows  force  to  be  used  on  the  material  while 
in  a  plastic  state,  but  prevents  its  being  crowded  out  of  the  cavity  and 
up  into  the  gum,  and  leaves  the  tilling  in  such  condition  that  but  little 
shaping  and  tinishing  are  necessary. 

Anv  suitable  matrix — the  one  previously  described  in  this  chapter 
is  recommended— having  been  adjusted,  gutta-percha  sutticient  to  fill 
the  cavitv  a  little  below  the  gum  margin  is  carefully  packed  into  j)lace 
with  warm  instruments.  Suthcicnt  heat  must  be  used  to  make  it 
thoroughly  plastic,  but  great  care  must  be  taken  not  to  l)urn  or  overheat 
the  material.  If  the  gutta-percha  is  overheated  its  physical  properties 
and  durability  are  very  much  impaired. 

All  cavities  where  gutta-percha  is  used  should  be  varnished  with  a 
thin  coatintr  of  white  resin  or  Canada  balsam  dissolved  in  chloroform. 
This  will  prevent  the  dragging  away  of  the  gutta-percha  from  the  walls 
of  the  cavity  in  finishing,  and  will  make  the  filling  water-tight. 

Sufficient  gutta-percha  having  been  put  in,  the  rest  of  the  cavity  is 
filled  with  cement.  The  matrix  being  in  place  and  properly  shaped,  the 
operation  is  reduced,  practically,  to  that  of  filling  an  occlusal  cavity. 

It  is  of  great  iinjiortance  that  the  cavities  be  kej)t  dry,  consequently 
the  rubber  dam  should  be  used  wherever  it  is  jiossible  to  do  so.  The 
cement  should  be  kei)t  dry  for  at  least  fifteen  minutes  after  it  is  put  in, 
and  then  covered  with  varnish  or  vaselin  to  ])revent  the  disagreeable 
taste  due  to  its  acid  reaction,  also  to  keep  the  filling  for  a  still  longer 
time  from  the  saliva  after   the  dam  is  removed. 

liecently  there  have  been  put  on  the  market  certain  zinc  phosphate 
cements  that  are  in  the  nature  of  hydraulic  cements.  Fillings  made  of 
these  should  be  allowed  to  get  wet  as  soon  as  they  are  in  position. 

Cement  will  wear  better  if  smooth  and  well  polished.  A  fine 
glossy  surface  can  be  obtained  with  an  oiled  burnisher  when  the 
cement  is  at  just  the  right  degree  of  hardness,  i.e.  when  but  slightly 
])lastic. 

An  excellent  lubricant  for  instruments  used  to  manipulate  gutta- 
percha or  cement  is  cocoa  butter.  A  small  iM)rcelain  druggist's  jar  into 
which  it  has  been   melted  is  convenient   to  have  on  the  operating  table. 


GUTTA-PERCHA   AND   GOLD— VARIOUS  KINDS  OF  GOLD.      345 

If  a  little  of  some  of  the  essential  oils,  cinnamon  or  cassia,  is  added  to 
the  melted  cocoa  butter  it  will  be  much  more  agreeable  and  keep  much 
better.  Plastic  fillings  will  rarely  stick  to  instruments  that  have  been 
rubbed  on  cocoa  butter.  If  a  shaving  of  it  is  placed  on  a  completed 
cement  filling  it  will  instantly  melt  and  flow  over  the  entire  surface, 
preventing  the  disagreeable  taste  when  the  dam  is  removed,  and  will 
keep  it  from  contact  with  the  saliva  for  some  time. 

GrUTTA-PERCHA   AND    GoLD. 

For  many  years  it  has  been  the  habit  of  some  good  operators  to  fill 
the  interior  of  large  cavities  with  gutta-percha,  covering  it  with  gold. 
Although  this  may  not  be  objectionable  practice  in  some  cases,  it  cer- 
tainly cannot  be  recommended  for  general  use.  The  principal  objection 
to  it  is  the  danger  of  frail  walls  being  fractured  by  the  subsequent 
expansion  of  the  gutta-percha.  So  many  instances  have  been  noticed 
where  fracture  has  followed  this  combination  that  the  fact  seems  well 
demonstrated  that  this  danger  exists.  Again,  there  is  no  need  of  com- 
bining these  two  materials  when  zinc  phosphate,  which  is  so  much 
better  tlian  gutta-percha  for  this  purpose,  is  available  and  does  not  pos- 
sess the  dangerous  quality  of  expansion  attributed  to  gutta-percha. 

Gutta-percha  and  Amalgam. 

What  has  been  said  in  regard  to  gutta-percha  and  gold  will  apply 
equally  well  to  gutta-percha  and  amalgam.  Rarely,  if  ever,  can  this 
combination  be  used  to  so  good  advantage  as  can  zinc  phosphate  and 
amalgam. 

Various  Kinds  of  Gold  in  Combination. 

(A)  The  So-called  Plastic  or  Crystal  Mat  Gold,  with  Other 
Forms  of  Gold. — Within  a  few  years,  preparations  of  gold  other 
than  that  known  as  foil,  or  foil  made  into  cylinders,  ropes,  and  so 
forth,  have  been  introduced  and  have  become  of  great  value  in  the 
filling  of  teeth. 

These  golds  are  commonly  known  as  "  plastic  gold."  The  term  is, 
however,  misapplied.  The  granular  quality  of  these  gold  preparations, 
i.  e.  lack  of  fiber,  is  what  gives  them  their  peculiar  and,  for  certain 
purposes,  very  valuable  working  qualities.  To  understand  this  charac- 
teristic, take  a  piece  of  White's  "crystal  mat  gold"  and  place  it  upon 
a  piece  of  blotting  paper,  then  press  the  point  of  a  medium-sized  gold 
packer  upon  the  centre.  It  will  be  observed  that  when  the  pressure  is 
applied  the  gold  is  not  inclined  to  curl  up,  but  rests  in  its  flat  posi- 
tion, and  the  instrument  has  cut  a  clean  track  in  the  gold,  condensing 
only  that  which  is  directly  under  the  point.     The  gold  being  without 


346 


COM  EISA  Tins    11 L  LISCS. 


"  fiber,"  SI)  ti)  speak,  the  jKU-lides  not  directly  under  the  jK)int  arc  not 
drawn  down  as  tlie  pressure  is  ai)plied.  This  is  why  this  chiss  of  gold 
is  so  useful  for  starting  Hllings. 

Now  take  a  cylinder  made  of  g(»ld  foil,  place  it  on  blotting  paper  as 
before,  and  with  tiie  same  instrument  press  on  the  centre  of  it.  It  will 
be  noticed  that  the  instrument  does  not  make  a  clean  cut  through  the 
cylinder,  as  was  the  case  with  the  ])iece  of  mat  gold,  and,  instead  of 
remaining  flat  on  the  blotting  paju'r,  it  is  inclined  to  curl  up.  The 
fibrous  quality  of  the  foil  is  an  advantage  when  a  corner  is  to  be  built 
on  to  a  tooth,  or  in  any  place  where  toughness  of  the  material  assists  in 
its  manipulation. 

By  using  these  gohls  for  starting  cavities,  the  peculiar  qualities  just 
referred  to  will  be  exhibited.  For  illustration,  we  will  take  an  extreme 
case — that  of  a  shallow  circular  cavity  in  the  buccal  surface  of  a  lower 
molar.  This  cavity  is  entirely  without  angles  or  undercuts,  its  walls 
flaring  outward,  the  bottom  being  flat, 
or  as  nearly  so  as  it  can  be  made  with 
a  large  bur  (see  Fig.  .336).  A  piece  of  ""H^.  W  W 
plastic  gold  a  little  larger  than  the 
cavity  is  placed  in  position,  then  with 

Fig.  336. 


Fig.  337 


Royee  ])luK(^ing  instruments. 

a  flat,  very  slightly  serrated  instrument  (a,  Fig.  332),  it  is  carefully  and 
gently  worked  into  place  and  partially  condensed,  then  a  smaller  instru- 
ment is  used  to  condense  around  the  edge.  As  only  the  portion  of  gold 
under  the  point  is  disturbed,  this  can  be  done  quite  readily  without  dis- 
lodging the  whole  piece.  Soon  sufficient  force  can  be  used  to  thoroughly 
condense  the  whole.  Care  must  be  used  in  selecting  a  first  piece  that  it 
be  not  too  large,  but  large  enough,  so  that  it  will  not  chop  up  as  it  is 
being  manipulated.  After  getting  the  first  piece  in  place,  the  filling  can 
be  finished  with  the  same  or  any  other  preparation  of  gold.  If  of  the 
same,  it  is  well  to  use  oval  points  (Fig.  337)  and  work  the  gold  toward 
the  sides  of  the  cavity  with  a  sort  of  rotary  motion,  keeping  the  edges 
of  the  filling  higher  than  the  centre. 

This  gold  is  very  soft  and  takes  a  very  sharp  impression  of  the  sur- 


VARIOUS  KINDS  OF  GOLD  IN  COMBINATION.  347 

face  on  which  it  is  packed,  as  shown  by  the  cross  lines  on  the  filling,  a, 
Fig.  336,  which  are  reproduced  from  those  made  in  the  cavity  shown 
at  b  in  Fig.  336.  The  lines  across  the  bottom  of  the  cavity  were  made 
with  the  sharp  point  of  a  hatchet  excavator. 

This  form  of  gold  can  be  used  to  advantage,  sometimes,  at  the  cervi- 
cal wall  of  compound  cavities,  provided  a  matrix  has  been  tightly  ad- 
justed. For  starting  fillings  in  approximal  cavities  in  the  front  teeth  it 
is  sometimes  invaluable,  and  it  can  be  used  in  conjunction  with  any  other 
form  of  gold,  or  interchangeably.  If  at  any  point  in  a  filling  the  oper- 
ator sees  a  place  where  he  thinks  he  can  put  a  piece  of  plastic  gold 
better  than  any  other,  there  is  no  reason  why  he  should  not  use  it. 
Sometimes  it  is  particularly  useful  to  thrust  into  soft  foil  to  make  a  sur- 
face upon  which  to  build  cohesive  foil.  It  can  be  packed  with  either 
hand  or  mallet  force,  and  with  smooth  or  serrated  instruments. 

(B)  Non-cohesive  and  Cohesive  Gold. — Strictly  speaking,  non- 
cohesive  gold  cannot  be  made  cohesive  by  annealing,  and  can  be  used 
only  on  what  is  known  as  the  "  wedge  "  principle.  "  Soft  gold,"  as  the 
term  is  generally  understood,  is  non-cohesive  when  used  without  anneal- 
ing, but  when  annealed  it  becomes  cohesive. 

Softness  and  toughness  are  the  qualities  necessary  to  make  tight  joints 
between  fillings  and  cavity  walls,  and  good  preparations  of  non-cohesive 
and  soft  golds  have  these  qualities.  Consequently,  a  method  that  will 
admit  the  use  of  these  golds  against  cavity  walls  with  a  sufficient  amount 
of  cohesive  gold  added  to  insure  strength  and  hardness,  when  strength 
and  hardness  are  necessary,  is  desirable. 

An  exaggerated  illustration  of  stopping  a  cavity  watertight  with  soft 
or  cohesive  gold  is  that  of  stopping  a  bottle  tightly  by  using  a  velvet 
cork  or  a  piece  of  hickory.  It  cari  be  done  with  the  hickory,  but  the 
time  required  to  do  it  perfectly,  as  compared  with  doing  it  with  the 
velvet  cork,  is  not  unlike  the  diflPerence  between  making  a  filling  of  soft 
and  one  of  cohesive  gold. 

Simple  cavities,  whether  in  occlusal  or  approximal  surfaces,  can  often 
be  half  or  two-thirds  filled  with  soft  gold  in  a  very  few  minutes,  and 
the  rest  of  the  cavity  filled  with  cohesive  gold.  A  filling  made  in  this 
manner  is  as  good  as,  or  even  better  than,  one  made  entirely  of  cohesive 
foil,  and  the  time  required  to  do  it  is  much  less,  as  the  soft  gold  can,  on 
account  of  its  softness,  be  used  much  faster  than  can  the  cohesive.  In 
cavities  of  easy  access  the  soft  gold  can  be  so  manipulated  as  to  be 
against  the  walls  of  the  cavity  at  every  point.  Small  cylinders,  or  any 
other  form  of  soft  gold,  can  be  set  around  the  edges,  and  the  central 
portion  of  the  cavity  filled  with  cohesive  gold.  Care  must  be  taken  to 
carry  the  cohesive  gold  into  the  soft  with  instruments  not  too  large,  so 
that  a  mechanical  union  between  the  two  golds  is  effected,  as  but  little 


''54 S  COMBTXATinx  FTLLTXGS. 

coliosioii  cMii  Ix'  had  Ix-twccn  soil  ami  culic-ivc  <:i)l(l.  In  larjjc  cavities, 
after  tin-  liivt.  |>icc('.-  ui"  >i)\\  onl<l  have  Ix'cii  put  In  place  and  eohesive 
<n»ld  witrkcd  ill,  llic  two  Uiiids  oi"  «iuld  can  l)c  used  iiitcrcliaiiiicalil\'.  A 
piece  ot'sott  ;:,(>l(l  can  l>e  placed  against  a  portion  oltlie  wall  ot'tlic  eav- 
itv,  followed  l)V  a  piece  of  cohesive,  which  is  first  attached  to  the  cohe- 
sive ])(n'tion  of  the  (illin<:-  and  then  used  to  force  the  |)iecc  of  soft  ^lAd 
to  its  jilace.  Dexterity  and  tact  in  nsiiit;-  these  two  uolds  to<;-ether  can 
onlv  be  ol)tained  1)V  e.\|)crience,  and  cai'cfnlly  notinj^  the  characteristics 
exhibited  under  nianipiilation. 

In  coin|)onnd  cavities  soft  o;old  plays  a  most  important  part.  Fill- 
ings in  these  cavities  fail,  nsnally,  at  the  cervical  wall,  and  too  mnch 
care  cannot  be  taken  in  inaUing  them  at  this  place  as  nearly  perfect  as 
possible.  F«)r  this  purpose  it  is  now  u-encrally  conceded  that  soft  gold 
is  mnch  better  than  cohesive. 

A  snitable  matrix  will  greatly  facilitate  the  oj)eration  and  assist  in 
obtaining  tiie  pnjper  contour.  The  tliorough  packing  of  the  gold  will 
also  be  mnch  simi)lified  if  the  cavity  is  so  prepared  that  the  walls  form 
no  acnte  angles  with  the  matrix,  therefore  attention  to  this  point  is 
im})ortant. 

A  matrix  having  been  properly  adjusted — the  one  described  under 
"Amalgam  and  (Jold"  fillings  is  recommended — one-half  or  two-thirds 
of  the  approximal  j)ortion  of  the  cavity  is  filled  with  soft  gold.  For  this 
purpose  soft  cylinders,  ropes,  j)ellets,  or  mats  can  be  used,  (ireat  care 
must  be  taken  in  condensing  the  gold  that  it  does  not  tilt  under  the 
instrument.  The  pressure  should  force  the  matrix  away  from  the  tooth 
enough  to  allow  the  g«tld  to  i)e  condensed  just  a  little  over  the  edge  of 
the  cavity,  so  that  when  the  biuMiisher  is  applied  there  will  be  sufficient 
gold  to  make  a  flush  filling. 

When  all  the  soft  gold  has  been  put  in  that  the  case  will  allow,  the 
cohesive  gold  should  first  be  added  in  very  small  pieces  in  order  to 
facilitate  the  driving  of  it  into  the  soft  gold,  so  as  to  make  a  strong 
union  between  the  two.  For  this  purpose  very  small  cohesive  cylin- 
ders or  No.  o  or  No.  4  foil  will  generally  be  used,  but  sometimes  No. 
30  or  No.  GO  foil  or  some  of  the  })lastic  or  crystal  gold  can  be  used. 
The  filling  can  be  finished  with  any  cohesive  gold,  that  kind  being 
selected  which  the  operator  has  found  by  ex])erience  he  can  best  manipu- 
late under  the  existing  conditions.  He  will  also  remember,  as  the 
work  goes  on,  that  a  piece  of  soft  gold  laid  against  an  exposed  wall, 
and  backed  ui>  with  cohesive,  as  before  described,  will  do  much  toward 
securing  a  good  filling. 

(C)  Soft,  or  Cohesive  Gold,  and  Heavy  Gold. — Fillings  of  soft 
or  cohesive  gold,  or  a  combination  of  the  two,  should  sometimes  be 
finished  with   heary  gold.     Nos.  30,  40,  60,  and   sometimes   No.  120, 


GOLD  AND   TIN— TIN-GOLD.  349 

can  be  used  to  advantage.  These  heavy  golds — which  are  usually 
rolled,  not  beaten — make  a  very  dense  filling,  and,  when  great  strength 
and  hardness  are  required,  they  are  preferable  to  lighter  grades. 

AVhen  a  filling  that  is  to  be  finished  with  heavy  gold  has  been 
brought  to  the  point  where  the  thick  gold  is  to  be  added,  the  surface 
should  be  as  nearly  level  as  possible,  as  it  is  difficult  to  adapt  the  heavy 
gold  to  indentations  and  irregularities.  The  instruments  used  should 
have  the  very  finest  serrations,  if  any  at  all.  The  gold  can  be  put  on 
by  hand  or  mallet  pressure,  or  by  burnishing  with  oval  points  having 
very  slight  serrations,  or  with  an  ordinary  burnisher.  When  done  in 
this  way  the  burnisher  is  apt  to  become  gold  plated,  and  the  instrument 
will  stick  to  and  drag  away  the  gold.  When  this  happens  the  gold 
plating  may  be  removed  from  the  steel  by  rubbing  on  a  piece  of  ink 
eraser,  on  flour-of-emery  paper.  The  most  efficient  way  to  keep  gold 
from  adhering  to  burnishers  or  instruments  used  for  making  burnished 
fillings  is  to  hold  them  in  an  alcohol  or  gas  flame  until  they  are  blued, 
repeating  this  as  often  as  necessary. 

In  using  heavy  gold  great  care  is  necessary  that  no  portion  of  the 
piece  added  be  left  uncondensed.  Hard  pressure  must  be  applied  to 
every  part  of  the  gold,  or  it  will  flake  ofi"  and  destroy  the  good  appear- 
ance, if  not  the  utility,  of  the  filling. 

Gold  and  Tin. 

Compound  cavities  are  sometimes  partially  filled  with  tin  and  then 
finished  with  gold. 

At  the  present  time  it  is  a  disputed  question  whether  tin,  if  used  as 
above  suggested,  will  not  be  dissolved  out,  after  a  time,  by  the  action 
upon  it  of  the  fluids  of  the  mouth,  leaving  a  cavity. 

It  can  be  used  exactly  as  described  for  soft  and  cohesive  golds,  sub- 
stituting the  tin  for  the  soft  gold,  or  for  a  portion  of  it^ — for,  as  a  rule, 
much  less  tin  would  be  used  than  soft  gold.  When  tin  is  used  it  can  be 
made  much  more  dense  if  it  is  packed  with  instruments  as  hot  as  can 
be  used  without  causing  the  patient  pain. 

If  desired  enough  tin  can  be  used  to  cover  the  cervical  wall,  followed 
by  sufficient  soft  gold  to  complete  one-half  or  two-thirds  of  the  filling, 
the  final  finish  being  of  cohesive  gold. 

The  matrix  will  be  found  of  the  same  service  as  in  the  case  of  soft 
and  cohesive  gold. 

Tin-Gold. 
The  term  "  tin-gold  "  has  been  applied  to  the  combination  of  tin  and 
gold  when  a  sheet  of  tin  and  a  sheet  of  gold  have  been  laid  one  upon 
the  other,  and  rolled,  folded,  or  crimped  together,  being  then  used  in 


350 


( OMJUX.  I  Tluy   Fl  L 1.  L\<.'S. 


the  same  luaniicr  as  iKni-colicsivc  foil,  (IcjM'inliiij;-  on  the  "  wcduc  "  priii- 
(•ij)lc  i'or  hdldiiiii-  in  the  tilliiii;.  Xarimis  autli<»riti('s  rccimuiicrKl  diH'cr- 
ciit  i^roportions  ot"  the  tin  and  n;()ld  to  he  w^'Ih]  in  this  manner.  All  the 
way  ironi  one-qnarter  of  tin  to  three-(|narters  of  pdd,  /.  r.  the  jH'opor- 
tion  of  one-quarter  of  a  sheet  of  tin  and  three-quarters  of  a  sheet  of 
gold  to  be  folded  or  crinijied  together,  to  three-cjuarters  of  tin  and  one- 
quarter  of  gold.     A  eonvenient  way  of  preparing  "  tin-gold  "  for  use 

Fig.  338. 


Foil  crimpers. 


Fk;.  339. 


eriiiipL'd  liu-gold. 


in    mediuni-si/ed    eavities    is  to  take  one-third    of  a   sheet  of  Xo.   4 
tin   foil,  upon  whieli  one-third  of  a  slieet  of  No.  '4   non-eohesive  foil 

is  laid.  It  is  then  placed  upon 
crimpers  (Fig.  '3;]8)  and  drawn  into 
an  evenly  folded  mass  (Fig.  339). 

This  is  to  be  cut  into  lengths 
suitable  to  be  used  for  the  cavity  in 
hand.  These  j>ieces  can  be  doubled 
to  make  blocks,  or  rolled  around  a  l)roach  into  cylinders,  if  desired. 
For  larger  cavities  one-half,  two-thirds,  or  even  a  whole  sheet  each 
of  the  tin  and  gold  foils  can  be  used.  For  very  small  cavities,  one- 
quarter  sheet  of  each   nuiy  be  suiticient. 

If  it  be  a  fact,  as  often  claimed,  that  tin  has  peculiar  preservative 
qualities  as  a  filling  nuiterial,  it  will  be  best  to  so  crimp  or  fold  the 
"  tin-gold  "  that  the  tin  will  be  on  the  outside,  in  order  that  it  may  be 
placed  against  the  cavity  walls. 

To  obtain  good  results  with  this  combination,  it  must  be  used  with 
the  same  care  and  accuracy  that  are  required  for  working  gold.  It  is 
very  tough  and  soft,  and  can  be  worked  with  great  rapidity  by  an 
expert.  For  method  of  using  see  cha]>ter  on  Non-cohesive  Tiold,  and 
work  "tin-gold"  as  there  descrilx-d  for  non-cohesive  gold. 

After  a  filling  of  "  tin-gold"  has  been  in  for  some  time  it  will  often 
be  found  to  have  changed  in  character,  and  instead  of  being  a  mass  of 
malleable  metal,  as  it  was  when  put  in,  to  have  become  hard  and  brittle^ 


A3fALGA3fS  OF  DIFFERENT  QUALITY— CEMENT  AND  ALLOY.       351 

closely  resembling  amalgam,  but,  unlike  it,  will  not  stain  or  discolor 
the  teeth. 

"Tin-gold"  is  recommended  for  use  in  the  temporary  teeth,  in 
occlusal  and  buccal  cavities  of  molars,  especially  in  teeth  of  poor  qual- 
ity, and  in  the  mouths  of  young  patients.  Small  approximal  cavities 
in  all  the  teeth  may  be  filled  with  it  to  good  advantage,  when  located 
where  its  dark  color  will  not  be  objectionable. 

"Tin-g-old"  and  Gold. — "Tin-gold"  can  be  used  in  connection 
with  gold  in  the  same  manner  as  has  been  described  for  the  use  of  tin 
and  gold,  or  soft  and  cohesive  golds. 

Amalgams  op  Different  Quality  in  Combination. 

For  certain  amalgams  is  claimed  a  greater  preservative  character 
than  is  possessed  by  others.  But  on  account  of  very  dark  color  or 
little  edge  strength  ^  they  may  be  undesirable  for  the  surface  of  fillings, 
especially  when  contour  is  necessary,  or  when  prominently  exposed  to 
view. 

In  simple  cavities  it  is  very  easy  to  fill  nearly  full  with  the  amalgam 
deemed  best  for  its  preservative  qualities,  and  to  finish  with  that  having 
superior  color  or  edge  strength  as  the  case  may  require. 

For  compound  cavities  fill  about  two-thirds  with  the  first-mentioned 
amalgam,  cutting  away  the  surfaces  and  exposing  the  entire  outer  rim 
of  the  cavity,  as  shown  in  Fig.  329.  The  matrix  is  then  adjusted  and 
the  remaining  portion  of  the  cavity  filled  with  amalgam  having  the 
requisite  edge  strength  for  contour  work. 

Cement  and  Alloy. 

Mixing  alloys  (such  as  used  for  amalgam)  with  cement  has  been 
recommended  to  a  certain  extent.  This  can  be  done  by  adding  from 
25  to  50  per  cent,  of  the  alloy  filings  to  the  cement  pow^der  and  then 
mixing  with  the  liquid,  or  the  alloy  may  be  worked  into  a  thin  mix  of 
cement. 

The  object  of  the  alloy  is  to  protect  the  cement,  in  a  measure,  from 
the  fluids  of  the  mouth,  thereby  making  the  filling  more  lasting. 

Another  combination  of  cement  and  alloy  which  has  proved  of  con- 
siderable worth,  especially  where  it  is  impossible  to  secure  proper  re- 
tention for  an  ordinary  amalgam  filling,  the  combination  having  a  very 
strong  adhesive  quality,  is  thus  described  by  a  well-known  writer : 

"  Ordinary  alloy  should  be   used,  and  not  the   recently  introduced 

quick-setting  varieties.     On  the  mixing  slab  should  be  placed  a  quantity 

of  zinc  oxid  powder  and  a  sufficient  quantity  of  the  liquid.     Now  mix 

the  alloy  in  the  usual  way,  but  do  not  express  the  mercury,  unless  in 

^  See  Chapter  XIII. ;  also  writings  of  Dr.  J.  Foster  Flagg. 


352  coMBrxA  Tiny  fil l tngs. 

considerable  excess,  a.s  ii  very  dry  mix  is  dilHcult  to  iiicdrporate  with 
the  cement.  Mix  the  cement  as  usual  for  use  as  a  filling,  and  immedi- 
ately mix  in  about  an  equal  quantity  of  amalgam,  using  a  stiff  steel 
spatula.  The  white  metal  or  bronze  spatula  should  not  be  used,  as  it  is 
acted  upon  by  the  mercury.  Now  you  have  a  stiff  plastic  mass,  which 
may  be  rolled  between  the  thumi)  and  finger  into  a  convenient  pellet 
and  placed  entire  in  the  cavity,  pressing  ean-fully  to  place  with  smooth 
burnishers.  A  perfect  contour  may  be  built  up  without  the  aid  of  a 
matrix. 

"The  mixture  is  extremely  adhesive  to  the  dry  cavity  walls,  and  no 
definite  retaining  shape  is  needed.  Some  of  the  amalgam  may  be  saved 
unmixed  with  the  cement,  and  can  now  be  burnished  over  the  surface 
of  the  combination  filling,  to  which  it  adheres  almost  greedily,  and  thus 
a  pure  metallic  surface,  like  a  veneer,  is  given  it  which  is  as  duralde  as 
an  amalgam  filling.  Or  a  quick-setting  amalgam  may  be  employed 
for  the  veneering, 

"  In  color  this  combination  is  like  amalgam,  but  is  more  granular  in 
appearance,  and  in  its  working  properties  resembles  stiff  cement.  When 
hard  it  takes  on  a  metallic  luster  under  the  burnisher  ;  if  sawed  through 
it  shows  a  metallic  surface.  It  is  less  soluble  in  the  oral  fluids  than 
oxyphosphate  cement,  but  less  durable  than  amalgam  alone,  except  when 
veneered  with  amalgam  as  described. 

"  Its  advantages  over  amalgam  are,  first,  its  adhesiveness,  which 
property  makes  it  apj)licable  to  cavities  in  which,  for  any  reason,  a  re- 
tentive form  cannot  be  obtained  ;  secondly,  the  rapidity  with  which  a 
large  cavity  can  be  filled,  a  valuable  item  where  dryness  cannot  be  long 
maintained,  and  making  it  unnecessary  to  employ  the  rubber  dam  in 
many  cases ;  thirdly,  the  ease  with  which  large  contours  may  be  made 
without  using  a  matrix. 

"  Its  advantages  over  cement  arc  its  greater  hardness  and  durability, 
but  it  is  less  agreeable  in  color,  hence  should  be  employed  only  in  the 
posterior  teeth." 


CHAPTEE  XY. 

RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 

By  Joseph  Head,  D.  D.  S.,  M.  D. 


Strictly  speaking,  the  term  inlay  may  be  applied  to  any  substance 
placed  in  a  tooth  cavity,  but  custom  has  restricted  this  term  to  fillings 
inserted  as  one  piece. 

In  primitive  times  teeth  were  filled  by  driving  a  solid  piece  of  lead 
into  the  cavity ;  gum  mastic  was  also  used  in  the  same  way ;  and  the 
green  stone  inlays  in  the  central  incisors  of  a  human  skull  discovered 
at  Copan,  Honduras,  probably  antedate  all  historical  record. 

Before  describing  the  construction  of  inlays  it  may  be  well  to  con- 
sider their  advantages  and  disadvantages ;  for  if  they  have  no  superi- 
ority over  other  fillings  to  counterbalance  their  inherent  defects,  inlays 
are  without  excuse  for  existence. 

Let  us,  therefore,  first  consider  the  main  characteristics  of  the  per- 
fect filling ;  and  then  by  a  comparative  table  of  various  filling  materials 
the  good  and  the  bad  points  of  each  may  be  justly  examined. 

The  characteristics  of  an  ideal  filling  may  be  stated  as  follows  : 

1.  Resistance  to  wear  of  mastication. 

2.  Resistance  to  action  of  oral  fluids. 

3.  Harmony  of  color. 

4.  Exclusion  of  bacteria,  and  preclusion  from  growth  of  those  that 
enter  the  margin. 

5.  Non-conductivity  of  heat. 

6.  Manipulation  easy  to  patient. 

7.  Manipulation  easy  to  operator. 

8.  Manipulation  not  destructive  of  healthy  tooth  structure. 

By  a  study  of  the  table  on  page  370  cohesive  gold  will  be  seen  to  pos- 
sess over  all  other  materials  the  sole,  though  important,  superiority  of 
greatest  edge  strength  and  resistance  to  the  crushing  force  of  mastication. 
True,  it  excludes  bacteria  from  the  cavity ;  but  experience  proves  that 
if  the  edges  of  a  cohesive  gold  filling  begin  to  leak  and  admit  micro- 
organisms, the  gold  seems  to  be  almost  entirely  lacking  in  the  antiseptic 
power  possessed  by  tin,  amalgam,  gutta-percha,  and  the  cements.     And 

23  353 


354 


RESTORATIOy  OF  TEETH  BY  CEMEyTED  INLAYS. 


■9jn 
-lonjjs    qjooj 

uoTjBindtuBK  '8 


INLAYS  COMPARED    WITH  OTHER  FILLINGS.  355 

while  it  resists  perfectly  the  action  of  the  oral  fluids,  it  so  utterly  lacks 
the  other  ideal  attributes,  as  already  enumerated,  that  with  front  teeth, 
soft  teeth,  and  teeth  of  nervous  patients  its  manifest  disadvantages 
more  than  counterbalance  its  advantages. 

Soft  gold  is  o})en  to  the  same  objections,  but  it  has  the  advantages 
of  resistance  to  wear,  resistance  to  oral  fluids,  and,  to  a  less  degree, 
exclusion  of  bacteria. 

Tin  has  to  a  marked  degree  the  good  and  bad  attributes  of  soft  gold, 
but  it  turns  black. 

Amalgam  bulges  under  mastication,  chips  on  the  edges,  rusts,  and 
leaks ;  but  it  often  prevents  decay,  by  filling  the  dentinal  tubules 
with  its  oxide.  When  rusty  it  is  a  moderately  poor  conductor  of  heat. 
It  is  easy  of  adaptation  both  for  operator  and  patient,  and  calls  for  a 
manner  of  manipulation  that  is  conservative  of  healthy  tooth  structure. 
It  is  therefore  often  available  where  gold  is  not. 

Oxyphosphate  of  zinc  has  all  the  advantages  lacking  in  cohesive  gold 
with  the  exception  of  color,  and  lacks  all  the  advantages  that  cohesive 
gold  possesses.  Its  edge  strength  is  solely  due  to  its  great  adhesion. 
It  wears  under  mastication,  dissolves  in  the  fluids  of  the  mouth,  and 
usually  absorbs  bacteria ;  but,  on  the  other  hand,  it  prevents  the  growth 
of  germs,  is  a  non-conductor  of  heat,  has  better  color  than  gold,  is 
easy  of  insertion  for  patient  and  operator,  preserves  weak  walls,  and 
does  not  require  undercuts. 

The  same  may  be  said  of  oxychlorid  of  zinc,  except  that  it  causes 
pain  to  sensitive  dentin  and  exposed  gums. 

Gutta-percha,  in  a  similar  way,  with  the  exception  of  color,  possesses 
the  good  points  lacking  in  cohesive  gold,  and  lacks  the  good  points  pos- 
sessed by  cohesive  gold.  It  loses  shape  and  wears  under  mastication, 
has  feeble  resistance  to  fluids  of  the  mouth,  has  poor  color,  and  leaks 
micro-organisms  ;  but,  on  the  other  hand,  it  inhibits  from  further  growth 
the  germs  that  enter,  is  a  non-conductor  of  heat,  is  easy  of  insertion  for 
both  patient  and  dentist,  and  has  a  manipulation  that  tends  to  conserve 
frail  though  healthy  walls. 

When  we  come  to  inlays  we  have  a  filling  in  which  the  good  points 
of  the  cement  are  combined  with  those  of  amalgam,  gold,  or  porcelain 
in  such  a  way  as  to  insure  the  advantages  of  both  in  the  largest  degree, 
and  to  reduce  to  a  minimum  the  disadvantages  of  each. 

When  a  cavity  is  lined  with  a  thin  zinc  cement  squeezed  out  by  the 
insertion  of  soft  amalgam,  this  amalgam  afterward  having  as  much  as 
possible  of  its  mercury  removed  and  the  edges  of  the  metal  burnished 
to  the  cavity  margins,  an  inlay  of  amalgam  is  to  all  intents  and  purposes 
made.  This  treatment  takes  away  from  the  amalgam  three  of  its  objec- 
tionable features,  conductivity  of  heat,  lack  of  adhesion  to  the  cavity, 


356  RKSToIi Alios   OF  TEETH  BY   CEMENTED   INLAYS. 

and  discoloration  of  adjacent  tooth  structure,  wliile  the  aihiptation  of 
the  phistic  metal  to  the  tooth  niarti:;ins  c^m  he  quite  as  perfect  as  though 
no  cement  were  used.  80  in  using  the  principle  of  the  inlay  with 
amaliiam  three  distini-t  advantages  are  gained  witliout  any  counteracting 
<lisadvantages,  all  of  wiiich  would  seem  to  indicate  that  whenever  possi- 
ble zinc  cement  should  be  used  under  amalgam. 

When  an  inlav  of  gold  is  cemented  into  a  cavity  with  <«.\y phosphate 
of  zinc  all  the  advantages  of  cohesive  gold  and  oxypliosphate  of  zinc  are 
obtained,  excepting  that  the  line  of  cement  remaining  at  the  margins 
may  in  time  prove  a  source  of  weakness.  J5ut  experience  lias  taught  us 
that  where  this  line  is  sufficiently  tine  to  prevent  capillary  attraction,  tiius 
preventing  a  constant  wash  and  change  of  solvent  saliva,  the  mucus 
held  in  place  by  capillary  attraction  will  act  as  an  effectual  bar  against 
harmful  destruction  of  the  cement.  Except  in  the  fine  line  above  men- 
tioned, such  a  filling  compared  with  the  ideal  filling  possesses  excellent 
resistance  to  mastication  and  to  the  action  of  oral  fluids,  it  has  power  to 
restrain  the  growth  of  bacteria  that  may  enter,  it  is  a  non-conductor  of 
heat,  and  is  easv  for  the  patient,  while  the  manipulation  involves  no 
greater  labor  or  loss  of  tooth  structure  than  is  entailed  in  the  use  of 
cohesive  gold.  The  two  possil)le  objections  that  can  be  raised  against 
the  filling  are  bad  color  and  an  edge  protected  by  a  soluble  cement. 
Hence — given  a  firm  tooth  structure  that  can  bear  the  mallet  without 
danger  of  being  crushed,  a  dentin  not  sensitive  to  thermal  changes, 
and  a  patient  not  too  severely  prostrated  by  the  necessary  malleting — a 
cohesive  gold  filling  is  superior  to  a  gold  iiday,  inasmuch  as  the  cohe- 
sive filling  may  have  edges  that  perfectly  exclude  bacteria,  even  though 
it  has  no  antiseptic  action.  Though  the  inlay  largely  inhibits  from 
growth  the  germs  that  enter  its  margins,  it  nevertheless  does  allow 
them  to  enter;  and  the  filling  that  keeps  out  the  germs  entirely  must 
be  held  superior  to  the  filling  that  admits  germs  and  then  inhibits  or 
destrovs  them.  Unfortunately,  in  the  soft,  sensitive  teeth  of  nervous 
patients  the  manipulation  of  cohesive  gold  does  not  result  in  the  exclusion 
of  decav  o-ernis.  The  tooth  margins  are  powdered  or  weakened  in  some 
wav  by  the  maniptdation  or  apposition  of  the  gold,  and  the  entering 
germs  cause  rapid  decay,  the  cohesive  gold  not  having  the  antiseptic 
power  of  restraining  them.  The  thermal  shocks,  and  the  overwrought 
condition  of  the  patient  that  sometitnes  lasts  longer  than  can  be  avoided, 
both  tend  to  produce  unhealthy  conditions  of  the  mouth  and  consequent 
tooth  dissolution.  In  such  a  mouth  the  iiday  is  indicated,  as  the  patient 
should  not  be  made  to  undergo  the  malleting  ;  and  since  the  germs  of 
decay  will  probably  enter  under  any  circumstances,  it  is  necessary  to  use 
a  filling  the  action  of  which  will  inhibit  or  prevent  their  growth. 

In  approximnl   cavities  where  the  filling  does  not  show,  and  where 


PORCELAIN  COMPARED    WITH  OTHER  MATERIALS.  357 

great  resistance  to  the  percussive  force  of  mastication  is  necessary,  the 
gold  inlay  is  usually  to  be  preferred.  Its  sole  objection  is  the  fine  line 
of  cement  that  connects  it  with  the  cavity  walls ;  but  if  the  gold  inlay 
be  properly  prepared,  burnished,  and  finished  as  hereafter  described, 
this  line  of  cement  may  be  rendered  so  microscopic  as  to  become  prac- 
tically no  longer  a  source  of  danger.  In  other  respects  the  gold  inlay, 
when  not  visible,  approaches  very  nearly  the  requirements  of  the  ideal 
filling,  having  the  advantages  of  perfect  resistance  to  mastication,  pre- 
clusion from  growth  of  bacteria,  non-conductivity  of  variations  in  tem- 
perature, easy  manipulation,  firm  adherence  to  cavity  walls,  and  an 
adaptation  not  usually  so  expensive  to  tooth  structure  as  is  the  ordinary 
insertion  of  a  gold  filling. 

We  shall  now  speak  of  the  porcelain  inlay,  which  in  labial  and  buccal 
cavities  fulfills  more  nearly  than  any  other  the  characteristics  of  the  ideal 
filling.     Such  a  filling  may  possess  color  that  really  matches  the  tooth. 

It  excludes  germs  of  decay  and  precludes  from  growth  those  that 
enter.  A  porcelain  inlay  is  a  non-conductor  of  heat,  it  adheres  to  cavity 
walls,  its  manipulation  is  easy  to  the  patient,  and  is  conservative  of  tooth 
structure.  The  only  real  objection  to  labial  porcelain  fillings  is  the 
fact  that  great  skill  and  patience  are  required  in  their  insertion.  Where, 
however,  porcelain  inlays  have  to  withstand  heavy  strain  in  mastication, 
as  in  Figs.  363,  368,  and  369,  they  are  liable  to  chip  on  the  edges.  This 
objection,  therefore,  renders  them  somewhat  less  serviceable  than  gold 
inlays  for  non-visible  approximal  cavities  in  molars  and  bicuspids.  For 
while  the  porcelain  is  sufficiently  strong  to  withstand  the  crushing  force 
of  mastication,  the  chipping  of  the  margin  tends  to  accentuate  the  weak- 
ness already  found  in  the  solubility  of  the  cement,  which  is  its  sole  defence 
against  bacteria.  If  such  chipping  occurs  on  the  masticating  surface  of 
the  molars  or  bicuspids,  the  fractured  margins  can  be  cut  out  with  a  fine  in- 
verted cone  bur,  filled  with  creamy  phosphate  cement,  and  this  cement, 
squeezed  out  with  sponge  gold  which  is  finally  condensed.  This  gives 
the  porcelain  an  edge  strength  equal  to  gold.  Thus  with  care  and  patience 
the  porcelain  inlay  acquires  the  advantages  of  gold,  cement,  and  porcelain, 
while  it  has  none  of  the  usual  disadvantages. 

The  Porcelain  Inlay. — The  work  of  making  and  manipulating  por- 
celain inlays  remains  to  be  considered. 

Pieces  of  porcelain  matching  the  natural  tooth  have,  in  times  past, 
been  ground  to  fit  the  cavities  and  then  held  in  position  with  cement. 
This  class  of  work,  however,  is  hardly  feasible  except  in  labial  cavities 
on  the  surfaces  of  the  front  teeth.  An  excellent  method  for  obtaining 
good  adaptation  is  to  proceed  as  follows  :  A  piece  of  tin-foil  should  be 
lightly  burnished  over  the  prepared  cavity,  as  in  Fig.  340,  b,  and  the 
edges  thoroughly  outlined  either  with  a  burnisher  or  a  plug  of  cotton 


358 


RESTORATloy  OF  TEETH  BY  CEMESTED   IS  LAYS. 


lijjlitlv  jirosscd  into  tlic  cavity,  inakins;  the  foil  appear  as  in  Fiji-.  340,  o. 
The  foil  witliin  tiic  line  of  (Icinarcatioii  is  then  cut  out  and  iilncd  to 
tlio  snrfaco  of  a  piece  of  jjorcclain  that  matches  the  tooth,  as  in  Fig. 
340,  f/,  the  porcelain  is  i^round  away  up  to  the  edges  of  the  tin  on  all 
sides,  and  'a  niod(M-ately  good  lit  is  thus  secured  (Fig.  340,  ,■).  This 
method,   however,    is   superseded   by   recent  discoveries ;  but   i'or  those 

Fig.  340. 


a,  Defect  at  gin<,'ival  margin ;  ft,  cavity  prepared ;  c,  mark  of  eilge  on  tin  foil ;  d,  tin  fnil  cut  out 
and  glued  to  artificial  tooth ;  e,  piece  of  porcelain  ground  and  cemented  into  the  cavity. 

who  are  interested  historically  Fig.  348,  ilhistrating  tln^  steps  of  the 
operation,  may  prove  of  value.  Keady-made  porcelain  inlavs  have  been 
kept  in  stock  for  years  at  the  dental  depots.  These  st<ippings  are  of 
different  shapes  and  sizes,  and  are  intended  to  be  ground  to  fit  the  cav- 
ities and  finally  to  be  cemented  in  place  (?^ig.  341).  Some,  however, 
instead  of  being  ground  to  fit  the  cavity,  require  the  cavity  to  be  ground 


Fig.  341. 


00000 


OOOOOOOoo 


ODOO 

Porcelain  cavity  stoppers. 


to  fit  them.  Dr.  George  H.  Weagant  has  devised  a  set  of  instruments 
suitable  for  this  process  (Fig.  342),  consisting  of  five  trephines,  of  con- 
secutive sizes,  made  of  copper  charged  with  diamond  dust.  These 
instruments  are  intended  to  cut  pieces  of  porcelain  out  of  an  artificial 
tooth  that  matches  the  color  of  the  natural  tooth,  and  the  cavity  in  the 
natural  tooth  is  prepared  with  one  of  Dr.  How's  inlay  burs  (Fig.  343) 


THE  PORCELAIN  INLAY. 


359 


corresponding  in  size  to  the  trephine.     This  method  has  several  serious 
objections,  one  of  the  principal  being  that,  in  order  to  give  the  cavity 


Fig.  342. 


Fig.  343. 


®     •     •    • 


®     ® 


y 


Dr.  Weagant's  diamond  trephines. 


Dr.  How's  inlay  burs. 


Fig.  344. 


a   circular    shape,    much    sound    tooth    structure   is    usually   sacrificed. 
Take,  for  example,   the    decayed    spot  shown    in    Fig.   344,  a.      This 
would  have  to  be  enlarged  as  in  Fig.  344,  6, — 
a  very  serious  objection. 

As  early  as  1882  Dr.  Herbst  advocated  glass 
fillings.  These  were  made  by  taking  impressions 
of  the  cavity  in  wax  and  making  two  moulds  in 
some  such  material  as  plaster  or  asbestos.  The 
ground  glass  was  then  flowed  into  the  first  mould, 
in  which  most  of  the  shrinkage  occurred.     The 

partly  formed  filling  was  then  removed  and  placed  in  the  second 
mould,  when  more  glass  was  added  until  the  filling  was  complete. 
Even  with  this  crude  method  the  results  were  fairly  satisfactory,  although 
the  margins  were  far  from  perfect  and  the  glass  was  permeable  to  such 
an  extent  as  to  blacken  ;  nevertheless,  fillings  were  made  that  preserved 
the  teeth  for  years. 

In  1887  Dr.  C.  H.  Land  made  mechanically  perfect  edges  possible 
by  devising  the  metal  matrix.  He  used  both  gold  and  platinum,  but 
found  the  latter  preferable,  as  platinum  could  be  adapted  with  a  facility 
equal  to  gold,  and  allowed  the  use  of  a  high-fusing  tooth  body  much 
stronger  and  less  likely  to  deteriorate  than  bodies  capable  of  being  fused 
on  gold,  which  of  necessity  require  so  large  a  percentage  of  glass  that 
they,  like  the  fillings  of  Herbst,  lacked  permanence  of  gloss  and  color. 
From  this  discovery  of  Land  dates  all  effective  porcelain  filling.  Before 
this,  pieces  of  porcelain  had  been  ground  to  fit  labial  cavities,  with 
fairly  good  results,  and  pieces  of  natural  enamel  from  extracted  teeth 
had  been  inserted  in  a  similar  fashion,  but  the  accurate  adaptation  of 
porcelain  to  approximal  cavities  was  impossible  until  the  metal  matrix 
was  evolved. 


360 


RESTORATION  OF  TEETH  BY  CEMENTED  IMAYS. 


At  present  the  advoeates  of  poreelain  fillinjrs  are  represented  by  two 
distinct  parties  :  those  who  advoeate  a  low-fnsing  poreehiin  that  ean  be 
melted  in  a  ^o\d  matrix,  and  tliose  who  advocate  a  poreehiin  ot'a  fnsing- 
point  and   resistance  at  least  eqnal   to   Close's  contiuuons-gnm   body, 


Fig.  345. 


I    I   I 


I 


12  3  4  5  6 

Diamond  points,  Nos.  1  to  6 ;  a,  copper  disk  charged  with  diamond  dust. 

necessitating  the  use  of  platinum  for  the  matrix.  It  is  claimed  by  the 
advocates  of  low-fusing  porcelains  that  gold  can  be  more  perfectly 
adapted  as  a  matrix  than  platinum.  This,  if  true,  is  a  very  important 
advantage.  But,  on  the  other  hand,  those  advocating  high-fusing 
porcelains  believe  that  they  can  get  as  perfect  an  ada])tation  with 
platinum  as  with  gold,  and  that  their  porcelains  have  a  better  color, 
are  stronger,  more  durable,  and  more  easily  manipulated,  thus  giving  to 
the  work  a  far  wider  range  than  seems  possible  with  any  low-fusing 
bodies  yet  devised,  for  porcelains  seem  to  have  strength  and  durability 
in  direct  proportion  to  their  fusing-points.  In  this  connection  we  should 
remember  that  when  brilliant  men  of  the  past,  through  long  series  of 
experiments,  were  perfecting  the  process  of  continuous-gum  work,  they 
would  undoubtedly  have  adopted  the  low-fusing  bodies  had  they  found 
any  that  would  melt  on  gold  and  remain  permanent.  That  they 
finally  resorted  to  platinum  and  made  durable  porcelain  bodies  at  their 
present  fusing-points  would  seem  to  indicate  that  low-fusing  porcelains 
are  unable  to  withstand  the  solvent  action  of  .saliva  and  the  force  of 
mastication. 

The  preparation  of  the  cavity  for  either  high-fusing  or  low-fusing 
porcelains  is  identical.  The  cavities  should  be  free  from  undercuts.  If 
these  are  unavoidable  through  extensive  decay,  the  cavity  should  first 
be  filled  with  oxyphosphate  of  zinc.  The  edges  should  be  sharp  and 
smooth,  and  where  they  are  approximal  there  must  be  sufficient  separa- 
tion to  allow  the  metallic  matrix  to  be  withdrawn  without  distortion,  as 


THE  PORCELAIN  INLAY. 


361 


success  is  impossible  with  a  distorted  matrix.  The  final  polishing  can 
be  best  accomplished  with  a  set  of  diamond  points  (Fig.  345),  or  with 
Arkansas    stone   points,  a  variety  of  which  can  be  had  at  any  of  the 


Fig.  346. 


Fia.  347. 


Fig.  348. 


Fig.  349. 


Fig.  350.         Fig.  351. 


dental  depots.  The  separation  may  be  obtained  with  rubber,  cotton,  or 
tape.  Approximal  cavities  between  front  teeth  may  be  sometimes 
advantageously  cut  freely  away  from  the  back,  as  in  Fig.  367,  a,  b,  c,  d. 


362 


RESTORATTOy  OF  TEETH  BY  CEMEXTED   INLAYS. 


When  till'  filliIlir^^  aiv  hftwoon  Incuspids,  tlic  lin<riial  walls  should  bo  cut 
UMspariugly  wlieuevcr  it  is  necessary.      Where  the  filling  is  to  stand  the 


Fig.  :?r)2. 


A,  Outline  of  labial  cavity ;  B,  platinum  foil  large  enough  to  be  readily  held  immovable  by  the 
first  and  second  fingers  during  the  formation  of  the  matrix. 

force  of  mastication  the  walls  at  the  cd^es  of  the  cavity  should  be  at  right 
angles  to  the  grinding  surface,  as  in  Figs.  363   and  368.     The  prepara- 

FiG.  353. 


A,  Outline  of  cavity  in  distal  aspect  of  lateral  incisor :  li,  platinum  folded  over  cutting  edge  to 
'    insure  immobility  and  to  give  outlines  of  tooth  so  that  a  perfect  contour  of  porcelain  may  be 
obtained. 

tion   of  the  cavity  being   completed,  if  high-fusing  porcelain  is  to  be 
used  the  matrix  must  be  made  with  rolled  platinum  one  one-thousandth 


THE  PORCELAIN  INLAY. 


363 


of  an  inch  in  thickness.  If  found  desirable,  thinner  platinum  may  be 
used  for  small  cavities ;  but  the  firm  burnishing  required  usually  re- 
duces the  foil  of  one  one-thousandth  of  an  inch  to  one  three-thousandth 


Fig.  354 


A,  Cavity  in  anterior  approximal  surface  of  first  molar. 

or  one  four-thousandth  of  an  inch  on  the  margins,  where  excessive 
thickness  of  the  metal  is  objectionable.  Foil  thinner  than  one  one- 
thousandth  of  an  inch  seems  to  lack  sufficient  body  to  stretch  properly 
without  tearing.  This  platinum,  if  annealed  in  a  Bunsen  burner  or 
blowpipe,  will  be  harsh  and  unfit  for  use,  but  when  annealed  in  a  muffle 
of  an  electric  furnace  it  becomes  soft  and  tough.  It  is  most  essential 
that  the  platinum  should  be  absolutely  soft.  The  platinum  is  placed 
over  the  cavity  and  pressed  with  spunk  or  bibulous  paper  as  far  as 
possible  without  tearing.  This  gives  us  the  greatest  possible  amount  of 
metal  with  which  to  form  the  mould.  The  edges  will  now  have  become 
distinctly  outlined,  and  from  this  time  the  platinum  should  be  held  ab- 
solutely immovable  or  good  results  cannot  be  obtained.  When  the  edges 
have  become  outlined,  they  should  be  gone  over  carefully  with  a  ball  bur- 
nisher, Figs.  346  and  347,  and  made  sharp  and  free  from  wrinkles,  the 
metal  then  spun  down  into  the  cavity  as  far  as  can  be  done  without 
danger  of  tearing.  Should  wrinkles  occur,  they  must  be  smoothed  out, 
before  they  reach  the  edge,  with  the  spatula  shown  in  Fig.  349.  When 
this  has  been  done  the  metal  should  be  boldly  swaged  to  the  bottom  of  the 
cavity  with  bibulous  paper.     This  can  frequently  be  accomplished  with- 


364  RESTORATION  OF  TEETH  BY  CEMENTFJ)  INLAYS. 

out  the  metal  tearing,  l)ut  if  tears  ilo  oeeiir,  tlii-y  are  (|uile  harmless,  as 
they  cannot  reaeh  the  edge  where  the  foil  has  already  been  adapted. 
Where  the  labial  cavity  extends  nntler  tlu?  gum,  the  large  ])ieee  of  foil 
extendintc  inimoval)ly  well  up  on  the  gum  and  swaged  down  on  the 
cavitv  with  biltulous  paper  will  form  an  arch,  and  press  and  hold  the 
gum  back,  so  that  the  ujiper  margin  of  the  cavity  will  be  defined  in 
cases  that  at  first  seem  absolutely  hopeless  of  success.  The  soft,  uiibur- 
nished  platinum  takes  a  beautiful  imj)ressi()n,  but  when  the  metal  has  been 
burnished  or  swaged  it  becomes  elastic  ;  if  therefore  the  matrix  be  moved 
during  its  formation,  an  accurate  impression  is  im]»ossil)le,  for  the  elastic 
platinum  when  distorted   cannot  be  forced  back  accurately  into  position 

Fig.  355. 


A,  Posterior  approximal  cavity  in  second  bicuspid;  B,  edfie  of  platinum  extending  over  first 

bicuspid  to  insure  mobility. 

until  it  has  been  reannealed.  When  complaint  is  made  against  ])latinum 
by  the  advocates  of  gold  matrices,  it  probal)ly  arises  from  the  fact  that 
they  try  to  work  the  platinum  in  the  same  manner  as  gold. 

The  matrix  when  finished  should  be  carefully  removed  and  heated 
to  redness  in  order  to  destroy  all  organic  material,  as  such  material  will 
tend  to  destroy  the  true  shade  of  the  porcelain. 

In  labial  cavities  the  piece  of  platinum  should  be  cut  sufficiently 
large  to  extend  i)eyond  the  two  adjacent  teeth,  and  the  metal  should  be 
moulded  to  the  three  tcetli  by  pressure  with  cotton  and  bibulous  paper. 
The  metal  is  then  held  firmly  upon  the  two  adjacent  teeth  by  the  first 


THE  PORCELAIN  INLAY. 


365 


and  second  fingers,  as  in  Fig,  352,  when  the  general  directions  for  adjust- 
ing the  matrix  to  the  cavity  may  be  readily  carried  out.  The  large 
piece  of  platinum  has  two  great  advantages  :  it  conduces  to  immobility 
of  the  metal  duriug  the  formation  of  the  matrix,  and  it  gives  the  entire 
labial  form  of  the  tooth,  so  that  an  accurate  idea  may  be  obtained  of 
the  desired  contour  of  the  filling. 

In  corners  of  centrals,  as  in  Fig.  353,  the  platinum  should  be  folded 
well  over  the  labial  and  lingual  surfaces  of  the  tooth ;  then  it  should 

Fig.  356. 


A,  Outline  of  approximal  cavity  ;  B,  flap  of  platinum  that  had  been  cut  away  and  turned  back  to 
facilitate  the  removal  of  the  matrix. 

also  be  bent  over  the  cutting  edge,  forming  a  sort  of  cap,  beneath  which 
shows  the  entire  contour  of  the  tooth,  and  by  means  of  which  entire 

Fig.  357. 


A,  Outline  of  cavity  as  formed  in  platinum  matrix  ;  B,  clamp  holding  platinum  immovable  while 
the  matrix  is  being  burnished  into  place. 

immobility  may  be  obtained  while  the  cavity  margins  are  being  defined 
and  the  matrix  formed. 

The  same  principle  applies  in  forming  a  half  cap  from  a  large  piece 


36G 


EESTORATIOX  OF  TEETH  BY  CEMENTED   IXLAYS. 


of  ])latimim  for  the  approximal  cavities  of  l)icus])ifls  and  molars.  The 
])latimiin  siiouUl  extond,  as  in  Figs.  354  and  35o,  from  grindini^  edge  to 
cervical  margin,  and  along  the  sides  of  the  adjacent  tooth.  This  can  be 
tirmlv  JK'ld  with  the  index  and  middle  fingers  of  the  left  hand,  while 
the  right  iiand  pri'sses  the  metal  with  cotton  partly  into  the  cavity.  The 
margins  and  tloor  of  the  matrix  may  then  he  dcHned  with  a  burnisher. 
It  is  most  important  that  the  greater  part  of  the  grinding  surface  of  the 
tooth  shall  be  outlined  in  making  this  mould,  as  by  this  means  a  truss 
effect  is  produced  that  will  ]>r(>vent  the  distortion  of  the  sides  of  the 
matrix  when  it  is  either  being  taken  oil"  the  tooth  or  when  the  porcelain 
is  l)eing  fused. 

In  mesial  cavities  the  metal  must  be  pushed  away  from  the  operator 
and  the  matrix  held  by  means  of  the  index  and  middle  fingers,  as  in  Fig, 
354.  In  distal  cavities  the  metal  is  pulled  toward  the  operator,  who 
works  around  and  beyond  the  hand,  holding  the  platinum  a.s  in  Fig.  355. 


Fig.  358. 


Position  of  fingers :  left  lower  bicuspid. 

When,  as  sometimes  occurs,  the  adapted  platinum  is  dovetailed 
around  the  teeth,  so  as  to  render  its  removal  difficult  or  impossible  with- 
out distortion,  the  outer  edge  of  the  ])latinum  cap  may  be  split  with  a 
sharp  knife  from  the  gum  line,  just  beyond  the  cavity  margins,  as  is 


THE  PORCELAIN  INLAY. 


367 


shown  in  Fig.  356.  Fig.  357  shows  a  method  of  obtaining  immobility 
of  the  matrix  by  a  clamp  that  sometimes  proves  useful.  Figs.  358 
and  359  show  the  position  of  the  fingers  when  manipulating  the 
matrix  on  the  lower  teeth.  This,  of  course,  should  be  done  while  the 
matrix  is  held  motionless  in  the  cavity.  It  is  sometimes  advisable,  in 
order  that  perfect  immobility  may  be  obtained,  first  to  pack  the  matrix 
full  of  bibulous  paper  or  cotton.  When  this  is  done  and  the  packing 
removed  there  will  be  no  difficulty  in  teasing  out  an  undistorted  matrix 
from  the  cavity. 

The  color  of  the  filling  must  next  be  decided  by  means  of  a  shade 
ring.  The  basal  color  of  nine-tenths  of  all  porcelain  fillings  is  light 
yellow,  and  white  added  according  to  necessity  will  in  a  large  number 
of  cases  be  all  that  is  required  to  obtain  a  perfect  match.  Whatever  tint 
is  desired,  the  basal  color  should  be  first  ascertained,  when  the  correct 
toning  material  may  be  added  with  comparative  ease.  The  thoroughly 
mixed  body,  being  wet  with  distilled  water  and  dried  with  blotting-paper 


Fig.  359. 


Position  of  fingers  ;  right  lower  bicuspid. 

or  muslin  to  the  consistence  of  dough,  is  placed  in  the  matrix  on  the 
point  of  the  brush  or  spatula  (Figs.  350  and  351),  and  settled  to  the  bot- 
tom with  a  rub  of  the  rough  handle  on  the  pliers  that  hold  the  platinum, 
more  porcelain  should  be  added  until  it  comes  to  the  edges,  which  should 
be  kept  scrupulously  clean. 

After  the  filled  matrix  has  been  carefully  dried  by  turning  it  face 
downward  on  a  piece  of  soft  muslin,  it  is  placed  in  an  electric  or  gas 
furnace^  as  the  case  may  be^  and  baked  until  a  gloss  appears. 


368  RESTORATION   OF   TEETH  BY  CEMENTED   INLAYS. 

This  bakinj;  will  cmise  it  to  shrink  about  one-fifth  of  its  bulk.  The 
partially  filleil  matrix  must  then  be  removed,  allowed  to  C(K)1  and  filled 
up  to  the  edges  with  porcelain  paste,  and  baked  again.  A  third  addition 
of  })()r('elain  may  or  may  not  be  needed.  After  bakintr,  the  filling  may 
be  taken  from  the  furnaee  almost  immediately,  as  ])racti('ally  oidy  very 
large  pieces  need  to  be  cooled  slowly,  although  theoretically  a  gradual 
cooling  will  make  the  porcelain  tougher.  The  ])latiiuim  should  now  be 
strij)pcd  off,  care  being  taken  to  pull  it  away  from  the  edge.  Should  it 
be  pulled  off  t(»war(l  the  edge,  chipping  is  likely  to  occur.  If  small 
portions  of  platinum  stick  to  the  porcelain,  they  can  be  peeled  off  with 
a  sharp,  tempered,  jwinted  instrument. 

In  large  or  difficult  cavities  a  double  burnish  is  sometimes  available. 
It  is  done  as  follows :  The  first  addition  of  porcelain  to  the  matrix  is 
not  allowed  to  come  to  the  edge.  This  is  baked  and  cooled.  The  matrix 
is  put  again  accurately  into  the  cavity,  held  immovably  and  the  edges 
reburnished.  But  with  the  ordinary  cavity,  the  theoretical  advantage 
of  the  second  burnish  is  more  than  overcome  by  the  danger  that  the 
matrix  may  not  be  accurately  put  back  into  the  cavity  before  the  second 
burnishing  is  begun. 

The  filling  is  now  ready  for  insertion.  Undercuts  may  be  carefully 
made  in  the  cavity  and  grooves  made  in  the  porcelain,  by  using  a  thin 
copper  disk  (Fig.  345,  a)  charged  with  diamond  dust,  so  as  not  to  mar 
the  edges.  This  is  usually,  if  the  proper  method  is  employed,  a  safe  and 
easy  procedure  with  the  smallest  fillings.  The  disk  and  porcelain  must 
be  kept  thoroughly  wet  during  the  cutting  of  the  grooves.  The  inlay 
should  be  so  held  that  the  edge  adjacent  to  the  intended  groove  may  be 
buried  in  the  skin  of  the  finger ;  the  groove  can  then  be  fearlessly  made 
by  the  swiftly  revolving  disk  that  cuts  only  the  hard  porcelain  and 
pushes  back  the  yielding  tissue  of  the  finger  without  inflicting  injury. 
If  the  porcelain  is  blackened  by  the  powdered  copper,  the  discoloration 
may  be  readily  removed  by  a  strong  jet  of  water  thrown  upon  it.  If, 
however,  the  undercuts  are  not  deemed  feasible  or  sufficient,  the  gloss 
from  the  under  side  should  be  removed  with  a  sandpaper  disk  or  w^ith 
hydrofluoric  acid.  The  kind  of  hydrofluoric  acid  to  be  used  is  called 
commercially  "  white  acid,"  and  it  can  Ix?  prej)ared  as  fi)llows :  to  the 
ordinary  hydrofluoric  acid,  carbonate  of  ammonia  should  be  added  to 
saturation.  This  should  be  evaporated  to  one-half  its  l)ulk  in  a  lead 
dish,  refilled  with  hydrofluoric  acid  to  its  original  bulk  and  once  more 
evaporated  to  one-half  its  bulk.  The  liquid  can  then  be  poured  into 
a  gutta-percha  bottle  and  kept  free  from  air  or  moisture.  This  will 
make  a  frosted  surface,  while  the  ordinary  acid  will  give  a  smoother 
etch. 

For  etching  the  following  method  should  be  pursued  :  the  face  of 


THE  PORCELAIN  INLAY.  369 

the  filling  should  be  imbedded  in  a  piece  of  soft  base-plate  wax,  leaving 
free  the  porcelain  that  is  to  enter  the  cavity.  A  drop  of  acid  is  then 
placed  upon  the  porcelain  and  left  there  for  about  one  minute,  when 
wax  and  |)orcelain  may  be  washed  in  water  and  the  filling  removed  from 
the  base  plate.  The  under  side  will  be  frosted  and ,  the  cement  will 
adhere  to  it  fairly  well,  but  not  so  well  as  though  efficient  grooves  had 
been  obtained. 

The  filling  and  the  cavity  should  next  be  washed  in  alcohol  and 
thoroughly  dried.  The  rubber  dam  may  often  be  put  on  with  advan- 
tage just  before  the  filling  is  inserted,  although  the  thorough  dryness 
of  the  tooth  thus  obtained  will  at  first  tend  to  make  the  filling  appear 
too  dark. 

The  method  of  inserting  the  filling  is  as  follows :  creamy,  slow-set- 
ting oxy phosphate  of  zinc,  corresponding  in  color  as  nearly  as  possible 
to  the  tooth,  should  then  be  placed  in  the  cavity,  and  the  filling,  picked 
up  by  means  of  a  little  cement  on  the  spatula,  be  pressed  home.  The 
porcelain  should  be  held  in  position  for  a  minute  or  two  until  the  oxy- 
phosphate  has  lost  its  elasticity  ;  for,  however  perfectly  the  porcelain 
filling  may  have  been  fitted,  if  it  does  not  go  accurately  into  place  the 
edges  will  be  as  imperfect  as  though  an  ill-adapted  matrix  had  been 
used.  As  before  mentioned,  a  creamy,  slow-setting  cement  is  essential, 
and  up  to  the  present  time  the  Harvard  cement  seems  best  to  satisfy 
these  requirements.  When  the  filling  is  finally  in  position  the  setting 
of  the  cement  may  be  hastened  by  a  blast  of  hot  air  or  a  hot  instru- 
ment applied  to  the  porcelain.  When  the  cement  is  wiped  away  and 
the  tooth  cleaned,  paraffin  or  varnish  should  be  flowed  over  the  filling, 
in  order  that  the  cement  may  set  for  six  hours  before  it  is  exposed  to 
the  action  of  the  saliva.  On  the  following  day  the  edges  may  be 
ground  with  an  Arkansas  stone  or  polished  with  sandpaper.  It  is 
better  for  finishing  that  the  edges  should  be  a  little  too  low  than  too 
high.  If,  however,  the  porcelain  is  too  high  it  can  be  ground  down 
and  still  give  good  results ;  but  the  original  gloss  is  in  most  cases  to  be 
preferred.  Having  described  the  general  operation  of  putting  in  a 
porcelain  filling,  a  few  cautions  may  not  be  out  of  place  before  describ- 
ing the  special  operations. 

Labial  cavities  should  be  made  deep  if  good  color  and  adhesion  are 
desired.  Overfusing  is  one  of  the  great  causes  of  poor  colors,  as  the 
more  the  porcelain  is  like  glass,  the  more  the  cement  beneath  will  destroy 
the  color.  A  bar  of  porcelain  running  into  the  tooth  makes  a  much 
stronger  anchorage  than  a  platinum  pin,  as  the  platinum  may  stretch  and 
it  always  tends  to  weaken  the  substance  of  the  body. 

In  large  contour^  excessive  contraction  may  be  avoided  by  adding  one 

24 


870  RESTORATION  OF  TEETH   11 Y   CEMENTED  INLAYS. 

part  in  four  ot"  a  colorless  liiiih-t'ii.sini:;  }>o\v<h'r  to  that  j)art  of  the  mixed 
ciiaiuel  which  is  to  be  used  for  tlie  first  bakiiii;.  The  imfiiscd  particles 
extend  across  the  matrix  in  every  direction,  making  what  is  practically 
an  internal  investment.  The  slight  lightening  thus  occasioned  is 
entirely  overcome  by  the  second  coat,  and  the  proper  contour  is  ol)tained 
in  fewer  bakings.  When  handling  small  fillings,  the  piiei's  and  cavity 
mav  l)e  atlvantagcously  k(>pt  w»t  uj)  to  the  time  of  insertion,  as  capillary 
attraction  will  prevent  the  filling  being  dropped  and  lost.  To  j)laee  a 
tiny  tilling  on  the  ojK-rating-case  in  the  same  relative  position  that  it 
will  take  in  the  tooth  prevents  mistakes  as  to  which  side  should  go  in 
first. 

In  addition  to  the  classification — labial,  buccal,  approximal,  contour, 
etc. — porcelain  fillings  are  to  be  considered  in  regard  to  their  ])osition 
in  the  mouth,  viz.  fillings  that" keep  their  color  when  cemented  into 
place,  and  those  that  will  be  darkened  In*  the  consequent  shadow.  Unless 
these  classifications  are  understood,  many  a  well-matched  porcelain  inlay 
will  end  by  appearing  dark  and  unsightly  in  the  mouth.  Color  varia- 
tions are  met  similar  to  those  that  are  seen  upon  examining  a  piece 
of  wiudow-glass.  The  surface  may  be  nearly  colorless  while  the  edge  is 
dark  green.  The  color  of  porcelain  fillings  is  dependent  upon  the  per- 
fection with  which  the  light  is  reflected  to  the  eye  of  the  observer.  For 
instance,  in  a  j)erfect  light,  yellow  porcelain  is  yellow,  because  all  of  the 
other  rays  that  make  u\)  light  are  absorbed  and  only  the  yellow  are 
reflected  to  the  eye.  If  the  light  be  gradually  decreased,  fewer  yellow 
rays  will  be  reflected,  and  the  color  will  become  darker ;  when  there  is 
no  light  reflected  the  porcelain  will  appear  black.  The  more  perfect  the 
front  and  side  lights  in  porcelain  fillings  the  less  will  be  the  shadow 
variations  in  color.  Take,  for  example,  a  simple  labial  cavity,  as  illus- 
trated in  Fig.  360.  If  this  extend  into  the  dentin  sufficiently  deep  to 
prevent  the  color  of  the  oxyphosphate  of  zinc  or  of  any  other  cement 
shining  through  it,  and  if  it  be  not  overbaked,  the  correct  color  of  the 
j)orcelain  will  be  given.  If,  however,  we  place  this  well-matched  material 
on  the  approximal  surface  of  the  tooth,  as  in  Fig.  361,  with  an  adjacent 
to(tth  shutting  off  direct  reflection,  and  thus  allowing  only  indirect  rays 
to  meet  the  eye  of  the  observer,  the  color  will  be  lost  in  shadow,  and 
from  having  been  a  perfect  match,  or  nearly  so,  the  shade  will  assume  a 
dull  lead  color,  .Also,  if  in  Fig.  360  the  labial  cavity  should  penetrate 
entirely  through  the  tooth,  through  the  lingual  enamel,  the  inlay  would 
present  a  problem  of  almost  insurmountable  difficidty  ;  for  nearly  all  of 
the  direct  rays  would  pass  through  it  and  would  be  lost  in  the  sliadows 
of  the  mouth,  while  the  side  lights  would  be  shut  off  by  the  non- 
transparent  but  necessary  zinc  cement.  This  difficulty  may  be  over- 
come by  placing  two  fillings,  one  on  the   lingual  and  one  on  the  labial 


THE  PORCELAIN  INLAY.  371 

surface.  The  oval  inlay  running  through  the  entire  tooth  substance  is 
mentioned  only  as  an  illustration  of  the  greatest  amount  of  color  varia- 
tion to  be  met  with ;  and  the  nearer  that  a  porcelain  inlay  approximates 
to  this  condition  the  greater  will  become  the  tendency  of  the  color  to 
be  lost  in  shadow. 

Take,  for  further  example,  the  two  fillings  shown  in  Fig.  362.  In 
each  illustration  the  fillings  go  evenly  through  the  labial  and  pal- 
atal walls  of  the  enamel,  and  yet  if  both  fillings  are  made  of  material 
that  matches  the  tooth  substance  the  corner  inlay  will  look  well,  while 
the  halfmoon-shaped  filling  will  be  dark.  If,  however,  b  does  not  go 
through  the  lingual  wall  and  the  cement  extends  entirely  behind  it,  its 
color  will  be  nearly,  if  not  quite,  as  good  as  that  of  the  corner,  it 
having  almost  assumed  the  classification  of  the  simple  labial  cavity 
before  mentioned.  The  difference  in  the  shades  of  these  two  fillings 
may  be  explained  as  follows  :  The  corner  (o)  is  illuminated  by  side 
light  from  the  cutting  edge,  while  the  halfmoon-shaped  filling  (6)  is 
shut  in  on  four  sides,  on  three  by  cement  and  on  the  fourth  by  the  adja- 
cent tooth.     It  must  be  further  noted  with  reference  to  the  corner  (a), 

Fig.  360.  Fig.  361.  Fig.  362. 


that  if  it  is  looked  at  from  directly  in  front,  or  from  the  direction  of 
the  arrow  X  toward  the  cement,  the  color  will  be  good ;  if,  however, 
it  is  looked  at  away  from  the  cement,  as  indicated  by  the  arrow  Y,  the 
color  will  be  lighter  or  darker  according  to  the  intensity  of  the  light ; 
but  the  true  color  will  not  be  seen.  This,  however,  is  not  a  serious 
objection,  as  the  filling  is  usually  seen  from  directly  in  front,  and  the 
occasional  side  views  are  equally  divided  between  good  and  bad  lights. 
We  may,  therefore,  feel  that  a  corner  inlay  which  does  not  include 
more  than  a  third  of  the  tooth's  cutting  edge  is  an  inlay  favorable  to 
the  obtaining  of  a  good  match.  Buccal  fillings  in  bicuspids  and  molars 
are  as  easily  matched  as  the  simple  labial  cavities,  for  they  come  under 
the  same  conditions  of  light  reflection  ;  but  all  approximal  inlays,  from 
the  posterior  surface  of  the  canines  back  to  the  molars,  show  the  same 
falling  off  in  color,  and  unless  allowance  be  made  for  this  falling  off 
disheartening  results  will  be  the  outcome  of  otherwise  careful  work. 
There  will  be  a  darkening  of  the  inlay  in  direct  proportion  as  the  cement 
shuts  oif  the  light  and  throws  a  shadow  into  the  body  of  the  porcelain. 
See  Fig.  367. 


372 


RESTORATIOS   OF   Tl.hTlI   II Y  CKMEl^TKl)   I  SLA  VS. 


Those  not  effected  are  simple  labial  cavities,  corners  of  centrals  and 
laterals,  and  cusps  of  canines  and  hicusjiids. 

Those  most  affected  are  tips  of  centrals  and  of  lateral  incisors,  and 
approximal  and  halfmoon-shaped  cavities  running  through  the  lingual 
enamel.  The  broader  the  adjacent  teeth  the  greater  will  be  the  shutting 
out  of  light  and  the  consequent  darkening  of  color.  Tips  of  central  and 
lateral  incisors  running  entirely  across  the  tooth  are  so  subject  to  the 
shadow  variations  from  (;ross  light,  side  light,  top  light,  and  bottom 
light,  that  the  restoration  of  more  than  a  third  is  not  advisable.  When 
half  of  a  tooth  has  been  carefully  matched  and  cemented  into  })lace,  the 
tip  may  look  very  well  in  good  daylight,  but  at  night  it  nuiy  turn 
dark ;  also  in  an  artificial  light  shining  from  above  the  tooth  and 
cement  line  show  very  dark  while  the  porcelain  seems  snow-white. 

And  now  let  us  consider  how  we  may  partly  conquer  these  shadow 
variations.  Halfmoon-shaped  cavities,  as  in  Figs.  361  and  362,  may  be 
filled  on  the  lingual  wall  with  gold,  an  absolute  match  thus  being  made 
possible,  but,  generally,  shadow  variations  can  be  best  overcome  by  a  judi- 
cious lightening  of  the  filling. 

And  now,  having  described  the  process  of  using  high-fusing  porcelain 
for  inlavs,  the  next  consideration  will  be  the  modifications  necessary 
when  the  low-fusing  porcelain  is  melted  in  a  gold  matrix.  The  best  of 
the  low-fusing  bodies  are  now  said  to  keep  their  color  and  texture  in  the 
mouth  indefinitely,  to  be  strong  enough  for  all  necessary  wear,  and  to 
retain  their  color  in  fusing, — which  would  indicate  that  the  low-fusing 
materials  have  greatly  improved  during  the  last  eight  ov  ten  years.  Of 
these  the  Jenkins'  body  seems  the  best.     Porcelains  capable  of  being 


Fio.  363. 


Fig.  364. 


Large  cavity  in  molar  tooth  involving  approximal  and 
grinding  surfaces.    Restored  by  porcelain  inlay. 


Showing  restoration  of  broken  lateral 
incisor  by  porcelain  tip. 


melted  in  a  gold  matrix  are  of  two  clas.ses :  those  that  are  sufficiently 
low-fusing  to  be  melted  in  a  bare  matrix,  and  those  that  melt  so  near  the 
fusing-point  of  gold  as  to  render  necessary  the  investment  of  the  gold 
matrix  in  order  to  prevent  its  being  warped  by  the  fire.  In  porcelains 
of  the  first  class  the  method  of  procedure  is  very  similar  to  that  in  which 
the  high-fusing  porcelains  are  fused  in  a  platinum  matrix.     The  No.  30 


THE  PORCELAIN  INLAY.  373 

gold  foil  is  placed  over  the  cavity  margins  in  a  manner  similar  to  that 
prescribed  for  the  use  of  platinum  ;  and  then,  instead  of  burnishing  or 
spinning  it  in  place,  it  is  pressed  into  all  parts  of  the  cavity  by  means 
of  spunk  or  cotton.  The  metal  is  so  soft  and  ductile  that  this  can  be 
accomplished  in  a  manner  impossible  with  platinum  ;  and  it  is  this  easy 
manipulation  of  the  gold  that  makes  the  sole  advantage  of  the  low-fusing 
over  the  high-fusing  porcelain  bodies.  The  gold  matrix  is  then  teased 
out  of  the  cavity.  This  must  be  carefully  done,  since,  being  more  easily 
adapted,  it  is  also  more  easily  distorted  than  the  platinum.  The  proper 
mixture  of  porcelain  is  placed  in  matrix  and  the  baking  is  performed 
exactly  as  with  the  high-fusing  materials,  the  only  marked  difference  in 
the  working  being  that  low-fusing  bodies  tend  to  spheroid  and  lose 
contour.  This  can  be  remedied  by  mixing  with  the  paste  a  small  quantity 
of  similarly  colored  high-fusing  porcelain. 

When  such  porcelains  are  used  as  require  the  gold  matrix  to  be 
invested,  the  matrix  must  not  be  torn  on  the  bottom  at  all,  for  in  such 
event  the  porcelain  will  tend  to  run  through  into  the  investment  instead 
of  drawing  away  from  the  crack,  as  it  does  from  a  platinum  matrix  where 
no  investment  is  used.  The  gold  matrix  must  be  dropped  bottom  side 
down  into  a  paste  of  asbestos  and  alcohol,  which  is  allowed  to  evaporate. 
Then  the  porcelain  may  be  flowed  into  the  matrix  little  by  little,  to 
minimize  warping. 

The  method  described  by  Dr.  J,  Leon  Williams^  is  as  follows  : 
"  The  thinner  the  gold  can  be  used,  the  more  perfect  the  fit  of  the 
finished  inlay.  A  proper  set  of  instruments  for  shaping  the  gold  form 
and  for  manipulating  the  porcelain  paste  is  an  important  matter.  I 
have  devised  for  these  purposes  the  set  of  instruments  shown  in  Fig. 
372.  They  are  all  double-end  instruments.  Nos.  1,  2,  3,  and  4  are 
designed  for  fitting  the  gold  form  to  the  cavity,  while  Nos.  5  and  6  are 
for  manipulating  the  porcelain  paste.  The  gold  should  be  cut  out  to 
represent  roughly  the  shape  of  the  orifice  of  the  cavity,  but  consider- 
ably larger.  Fig.  366  shows  the  proper  shape  for  such  a  cavity  as  is 
shown  in  Fig.  367  at  a.  It  will  greatly  facilitate  the  shaping  of  the  gold 
form  if  a  notch  be  cut  out  of  the  gold  as  shown  in  Fig.  366,  and  at  the 
same  time  decrease  the  chances  of  breaking  through  the  gold  in  forcing 
it  into  the  shape  of  the  cavity.  It  should  first  be  introduced  into  the 
cavity  without  annealing.  The  cut  edges  will  then  slide  over  each  other 
as  the  centre  of  the  gold  is  forced  to  the  bottom  of  the  cavity.  .  .  . 
Then,  with  the  cotton  or  spunk  tightly  packed  in  the  cavity,  take  instru- 
ment No.  2  and  most  carefully  burnish  the  gold  around  the  entire  edge 
of  the  cavity.  This  instrument  will  be  found  well  adapted  to  reach 
every  part  of  the  margin.  It  will  generally  be  found  best  to  hold  the 
cotton-wood  back  a  little  from  the  margin  of  the  cavity  when  one  is 

^  Dental  Cosmos,  November  1899,  vol.  xli.  p.  1087. 


374 


EESTORATfON  OF  TKETII  BY  CEMENTED  INLAYS. 


l)iirnisliin(r,   with   :iii    inslruincut    li(>l(l   in    tlio  left    liand,   and   with    this 
in.struinc'iit  Q)ivli.Tahly  a  ball   burnished)  also   press  the  eutton-w.K.l  well 


r 


Fig.  365, 


into  the  cavity.  This  holds  the  gold  form  well  in  place 
and  })reveuts  rocking  while  the  edges  are  being  bur- 
nished. 

"  Most  operators  have  found  the  removal  and  imbedding 
of  the  gold  to  require  the  most  delicate  manipulation,  and 
by  the  methods  heretofore  described  one  is  never  quite 
certain  whether  or  not  this  part  of  the  operation  has  been 
successfully  performed  until  the  inlay  has  been  com])leted 
and    tried    in    place.     All    of  this    uncertainty    may    be 


THE  PORCELAIN  INLAY. 


.75 


avoided  by  the  following  procedure  :  Slightly  warm  and  roll  up  in  the 
fingers  a  small  ball  or  pledget  of  hard  white  wax,  such  as  is  supplied 
for  crown-  and  bridge-work.  The  ball  of  wax  should  be  just  a  little 
larger  than  is  necessary  to  fill  the  cavity  completely;  that  is  to  say,  it 
should  slightly  project  over  the  margin  of  the  cavity  all  round.  The 
wax  should  be  quite  stiflp  when  introduced  into  the  gold  form  as  it  lies 
in  the  cavity  of  the  tooth.     Now  take  the  broad,  thin  burnisher,  shown 


Fig.  366. 


Fig.  367. 


Sheet  of  gold  or  plat- 
inum, notched  and 
ready  for  adaptation 
to  cavity. 


Right  superior  central,  showing  two  large  approximal  cavities 
to  which  access  is  obtained  by  cutting  freely  from  the  lin- 
gual walls  :  a,  tooth  with  cavities  prepared ;  6,  porcelain 
inlays  for  same :  c,  tooth  showing  lingual  surface;  and  d, 
labial  surface  after  cementing  of  inlays. 


in  No.  4,  Fig.  365.  and  press  the  ball  of  wax  firmly  into  place.  To  pre- 
vent the  burnisher  from  sticking  to  the  wax,  it  should  first  be  dipped 
into  French  chalk  or  pulverized  soapstone.  In  such  cavities  as  are 
shown  in  Fig.  367,  at  a,  broad  polishing  tape,  dusted  with  French 
chalk,  may  be  used  for  pressing  the  wax  ball  into  place  ;  but  great  care 
should  be  exercised  not  to  pull  the  tape  the  least  in  one  direction  or  the 
other,  as  one  would  do  in  poli.shing  a  filling.  This  would  rock  the  gold 
form  and  mar  the  fit.  The  pull  should  be  steadily  and  equably  from 
both  ends  of  the  tape,  the  object  being  to  press  the  wax  everywhere 
firmly  over  the  edges  of  the  cavity.  A  stream  of  cold  water  should 
now  be  thrown  on  the  wax,  and  then  the  wax  and  gold  form  should 
be  quickly  removed.  If  this  part  of  the  operation  is  done  with  ordinary 
care,  the  finished  inlay  will  always  be  found  to  fit  perfectly.  To  facili- 
tate the  quick  removal  of  the  form,  care  should  be  taken  to  prevent 
the  wax  overlapping  the  gold  much  at  any  point  outside  the  margin  of 
the  cavity.  To  prevent  this  and  al.so  to  assist  in  securing  proper  imbed- 
ding of  the  gold  matrix  it  is  well  to  let  the  margin  of  the  gold  project 
as  much  as  possible  beyond  the  edges  of  the  cavity. 

"  The  matrix  may  now  be  imbedded  without  the  slightest  fear  that 
its  shape  will  be  changed.  For  imbedding  material  I  use  plaster  and 
marble-dust.  When  the  investment  is  sufficiently  hard  the  wax  is  thor- 
oughly melted  out  with  a  stream  of  boiling  water.  The  investment  is 
then  dried  and  brought  to  a  full  red  heat  with  the  blowpipe.  It 
is  then  allowed  to  cool,  and  is  ready  for  packing.     Now,  the  first  step 


376 


RFSTORATfOy  OF  TEETH  BY  CEMENTED   TXLAYS. 


in  tlio  packiiii;  of  the  porcelain  pnsto  is  the  all-important  ono  to  ]>rovent 
tlie  [)ore('Iain  shrinking  away  iVoin  tlit'  walls  of  tlu'  matrix.  Tiiis  may 
always  be  accomplished  easily  with  porcelain  of  any  make  if  the  follow- 
ing instructions  are  carefully  ohserved  :  ^lix  the  ]K)rcelain  paste  to  the 
consistence  of  soft  putty,  and  with  the  upper  j)oint  shown  in  No.  0,  Fig. 
365,  place  a  ring  of  this  putty  around  the  entire  circumference  of  the  cavity 


Fig.  368. 


Fkj.  369. 


Showing  bicuspid  with  cavity  involving  approxi-  Canine  tooth  showing  at  n,  large  cavity,  and 

mal  and  grinding  surfaces:    «,  tooth  with  at  band  r,  large  porcelain  inlay  restor- 

cavity  prepared  ;  (*,  poicelain  inlay  ;  r,  inlay  ing  contour  of  tooth, 
cemented  in  place. 

leaving  the  centre  quite  free  or  empty.  In  melting  a  porcelain  paste  it 
naturally  shrinks  toward  the  largest  ma.ss  of  its  own  body,  or  toward 
the  centre  of  the  mass.  If,  then,  this  centre  be  removed  we  should 
naturally  expect  the  mass  to  shrink  toward  the  circumference,  and  this  is 
precisely  what  happens  when  manipulated  as  directed.  The  matrix 
always  comes  ont  from  the  first  baking  with  the  porcelain  everywhere 
firmly  melted  to  the  walls  of  the  matrix.  Nor  will  it  start  from  this 
position  at  any  subsequent  baking  unless  it  is  very  much  overheated. 
"After  each  packing  of  the  porcelain  paste,  a  small  camel's-hair  brush 
with  a  fine  point  should  be  moistened  (this  is  best  done  by  drawing  it 
between  the  lips  after  the  manner  of  water-color  artists)  and  drawn 
around  the  margin  of  the  matrix  to  remove  all  overhanging  particles  of 
the  paste.  If  this  be  not  done,  the  margins  of  the  inlay  will  often  be 
found  ragged,  and  a  perfect  margin  is  the  most  essential  feature  of  a 
porcelain  inlay.  If  gum-water  be  used  for  mixing  the  paste,  it  will  be 
found  necessary  to  remove  these  overhanging  particles  with  great  care, 
as  the  tendency  naturally  is  for  the  gum-water  to  cause  the  particles  of 
powdered  porcelain  to  stick  to  the  gold  or  j)latinum  margin  of  the  ma- 
trix. In  building  up  the  inlay  for  restoring  lost  corners  of  teeth  and  for 
general  contours  the  work  will  be  much  facilitated  if,  after  the  first 
baking  has  been  carried  through  as  ai)ove  described,  to  secure  perfect 
union  with  the  walls  of  the  matrix,  a  small  piece  of  solid  porcelain  be 
placed  at  the  point  representing  the  highest  point  of  the  contour  of  the 
inlay.  These  pieces  of  porcelain  may  be  made  by  crushing  old  porce- 
lain teeth  in  an  iron  mortar.  Care  should  be  taken  to  use  a  piece  small 
enough  so  that  the  outer  edge  will  not  show  thronirh  when  the  inlav  is 


THE  PORCELAIN  INLAY.  377 

completed.     Corners  like  the  one  shown  in  Fig.  369  may  be  produced 
in  this  manner  without  much  difficulty." 

Dr.  Williams's  method  of  separating  the  gold  matrix  from  the  porce- 
lain, and  grooving  the  inlay  and  cementing  it  into  the  cavity,  need  not 
be  dwelt  upon,  the  subject  having  already  been  fully  discussed. 

In  summing  up  the  advantages  and  disadvantages  of  the  high-fusing 
and  low-fusing  bodies  it  will  be  seen  that  the  advocates  of  the  low-fusing 
materials  claim  the  sole  point  that  gold  is  more  easily  adapted  as  a 
matrix  than  platinum  ;  while  the  others  claim  that  porcelains  of  high- 
fusing  bodies  are  known  to  be  permanent,  to  keep  their  color  under 
firing,  to  contour  without  spheroidal  tendency,  to  dispense  with  the 
use  and  consequent  restrictions  of  an  investment,  and  to  furnish  a 
process  so  simple  and  reliable  that  fillings  may  be  constructed  with 
greater  certainty  of  good  results  and  with  more  rapidity. 

There  are  three  classes  of  furnaces  that  can  be  used  for  fusing  por- 
celains— gas,  gasoline  and  electric.  The  gas  and  gasoline  furnaces  are 
noisy,  odorous,  and  dirty  ;  but  seldom,  if  ever,  get  out  of  order.  On  the 
other  hand,  the  electric  furnace  is  clean,  silent,  and  beautiful ;  but  it  has 
only  a  limited  life.  Even  in  experienced  hands  its  wires  will  burn  out 
and  need  mending  once  or  twice  a  year,  and  with  the  inexperienced 
it  may  easily  be  rendered  useless  in  a  few  seconds.  Nevertheless,  in 
spite  of  this  drawback,  the  electric  furnace  is  to  be  preferred  to  the 
others,  while  the  gas  and  gasoline  furnaces  are  suitable  only  for  the 
laboratory.  The  only  feasible  gas  furnaces  for  high-fusing  bodies  are 
those  which  have  a  platinum  muffle,  in  which  the  fusing  porcelain 
can  be  thoroughly  protected  from  the  gas,  for  fusing  porcelain  cannot 
keep  its  color  if  subjected  to  the  products  of  combustion  of  carbon. 
The  two  most  practicable  gas  furnaces  for  high-fusing  bodies  are  the 
Downie  (Fig.  370)  and  the  Midget  Land.  Either  of  these  properly 
manipulated  will  fuse  continuous-gum  body  within  three  minutes.  They 
work  on  the  blowpipe  principle,  and  necessitate  either  a  pressure- 
reservoir  or  labor  with  the  foot-belows.  Two  gasoline  furnaces  are 
available — the  Brophy  and  the  Turner  furnaces,  and  these  are  worked  by 
gasoline  blowpipes — very  odorous  and  in  careless  hands  dangerous.  The 
electric  furnaces  are  based  on  the  principle  that  platinum  wire  submerged 
in  fire-clay  will  become  red-hot  when  a  current  is  passed  through  it.  The 
fire-clay  stores  up  this  heat  indefinitely,  so  that  any  degree  of  temperature 
below  the  fusing-point  of  platinum  may  be  obtained.  This  fusing-point 
is  said  to  be  about  4500°  F.  The  best  furnace  for  high-fusing  bodies 
that  require  a  temperature  of  from  2500°  to  3000°  F.  is  the  Hammond 
electric  crown  furnace.     (See  Fig.  371.) 

The  gas  outfit  of  Dr.  Jenkins  is  neat  and  effective ;  in  fact,  as  a  gas  out- 
fit it  is  almost  ideal,  but  can  only  be  used  for  low-fusing  bodies.     The  little 


378 


liESTORATroy  OF  TEF/riT  II Y  CEMENTED   IS  LAYS. 


electric  (tven  made  l»y  Ash  (Fit;.  o7-"))  is  jx'rf'ect  for  low-fiisiiifr  bodies, 
and  wherever  a  ciirreut  can  l)e  secured  tliis  litth'  furnace  is  to  Ix-  stroiiirlv 
recomniendi'd.  Its  oidy  (h'awhack  is  that  it  cannot  he  nieinU'd,  and  that 
if  a  burn-out  occur  it  must  l)e  sent  to  the  manufacturer  for  a  new  coil  of 
wire.  It  has  not  sufficient  power  to  melt  the  hii;h-fusing  bodies  quickly 
and  well. 

The  Gold  Inlay. — As  previonsly  said,  the  fjold  inlay  has  practically 
perfect  edge-strength,  and  therefore  is  sometimes  to  be  preferred  to  the 


Fi.i.  :?7o. 


Downie  gas  crown  furnace. 

porcelain  inlay  in  the  back  of  the  mouth,  where  its  color  is  no  objection 
and  where  its  power  of  resisting  mastication  is  of  prime  importance. 
The  gold  inlay  is  easy  to  make.  The  cavity  should  be  prepared  along 
the  lines  previously  mentioned.  Then  soft  gold  plate,  86  gauge,  should 
be  held  immovably  over  it  and  burnished,  and  swaged  into  posi- 
tion. Small  tears  at  the  bottom  are  of  little  consequence.  When 
the  matrix  has  been  fitted,  while  it  is  still  in  the  tooth,  moss  fibre  or 
sponge  gold  should  be  packed  quickly  and  firmly  into  it  up  to  the 
edges,  and  to  the  proper  contour.     If  this  gets  wet  during  the  process. 


GOLD   INLAY. 


379 


no  harm  results.     The  edges,  however,  should  be  left  clean.     The  filled 
matrix  should  be  removed  and  22-k.  solder  flowed  over  all,  keeping  the 


Fig.  371. 


The  HaiuDioiid  furnaci;  Xo.  1. 

Fig.  372. 


Dr.  Jenkins'  miniature  gas  furnace. 


edges  still  clean.     The  filling  should  then  be  cut  out,  leaving  a  small 
margin  of  the  gold  plate  at  the  edges.     It  is  then  placed  in  the  tooth 


380 


RKSTOUATIOS   or   TKKTII   />')'   ('KM  EST  ED    /XLAYS. 


cavity  airal!),  wcdirctl   imniovahly,  and    hnniislicd  on   the  cdircs  a  soc(»ii(l 
time,      ll'  iiKtri!  .s|)(»nge  gold  is   lU'cdcd   lor  contour,  it  can  he  added  and 


Fk;.  373. 


Ash  electric  oven. 

soldered  fast.  The  edges  can  finally  be  filled  to  full  contour  with  22-k. 
solder.  It  is  polished,  undercut,  and  set  with  cement  in  the  usual 
manner. 

Fia.  374. 


Showing  details  of  the  proces.s  for  making  cast  filling  for  incisor:  a,  pest  with  plate  adapted; 
B,  restored  contour  in  wax;  c,  the  contour  invested;  d,  cast  contour  detached;  e,  e,  the 
finished  restoration. 

Dr.  C.  L.  Alexander's   method '  is  described  by  its  author  as  fol- 
lows:  "  My  method  consists  in  detail  of  burni.shing  platinum  over  the 
surface  to  be  restored  ;  the  holes  fi)r  retaining  posts  having  already  been 
^  Dental  Cosmos,  October  1896,  vol.  xxxviii.  p.  850. 


GOLD  INLAY. 


381 


made,  can  easily  be  located  and  the  posts  adjusted  therein.  Then  by 
heating  a  little  modeling  compound  over  a  spirit  lamp,  and  pressing  it 
firmly  down  over  the  surface  and  allowing  it  to  cool,  w^e  can  remove  the 
platinum  sheet  and  posts  in  correct  relation  to  each  other.  We  now 
invest  and  solder  the  posts  with  pure  gold.  The  piece  is  again  placed 
upon  the  tooth  in  the  mouth,  and  after  carefully  trimming  and  rebur- 
nishing  an  impression  is  taken,  and  when  an  occlusion  is  needed  it 


Fig.  375. 


Fig.  376. 


Restoration  of  bicuspid 
by  cast  filling. 


Front  and  back  view  of  an  incisor  restoration,  and  cast 
filling  for  molar. 


is  made  at  the  same  time  by  the  patient  closing  the  teeth  together 
before  the  impression  material  has  become  hard.  The  metal  founda- 
tion will  be  drawn  out  by  the  impression  compound  when  it  is  removed 
from  the  mouth.  Each  side  of  the  impression  thus  secured  is  filled 
with  any  good  investing  material  and  placed  in  an  articulator.  After 
heating  and  removing  the  impression  material,  the  contour  of  the  tooth 
may  be  restored  by  building  up  with  wax.     Over  the  wax  surface  thus 


Fig.  377. 


Foil  matrix  invested.    Cast  filling  for  molar. 

formed  gold  or  platinum  foil  is  burnished;  if  the  former,  it  should  be 
very  heavy,  say  No.  60.  A  suitable  portion  of  the  wax  being  left 
uncovered,  the  work  is  cut  away  from  the  model  and  invested,  with  the 
exception  of  that  part  of  the  wax  left  uncovered  by  the  metal.  Through 
this  opening  the  wax  is  boiled  out,  leaving  a  matrix  lined  with  metal, 
which  acts  as  a  carrier  for  the  fused  gold ;  20-  or  22-carat  gold  solder 


382  RKSTollATIOS   OF   TEKriI    IIY    <  F.M  F.STi:!)    IM.AYS. 

should  1)0  u.<o(l  for  tlii.s  purpose,  Wlicii  pure  «inl(l  is  w^vd,  u\  ocnirsc 
the  matrix  must  Ix'  lined  with  ])liitinum  thronirhout.  WIumi  removed 
from  the  investuient,  the  easting  is  iiuishetl  and  eeineuted  (o  its  jH)sition 
in  the  tooth. 

''  In  bicuspids  and  molars  it  will  IVecjuently  he  found  more  con- 
venient to  stam]>  up  the  cusps,  usin^  pure  gold,  35  gauge." 

The  pieces  made  as  described  by  I)r,.Ale\an(h'r  may  be  used  as 
abutments  for  bridge -W(U-k.  The  gold  inlays  are,  of  course,  to  be 
cemented  into  phice  with  great  care  as  regards  asepsis,  <h-yness,  and 
api^osition.  They  have  a  great  advantage  over  tlu^  j^orcelain  iiilavs  in 
that  their  edges  can  be  burnished  into  place  while  the  cement  is  soft  ; 
and  therefore  when  they  are  being  given  their  final  j>olish  with  the 
sand])aper  disk,  the  (hsk  should  always  be  run  toward  the  margins,  so 
that  a  feather  edge  will  be  formed,  which,  with  the  burnishing  men- 
tioned, will  make  an  almost  absolute  joint  possible. 

A  Hard-Rubber  Inlay. — Some  dentists  advocate  making  cemented 
inlays  of  hard  rubber  approximating  the  tooth  in  color.  These  iidays 
are  feasible  only  where  a  perfect  impression  can  be  readily  taken  of  the 
cavity,  the  filling  being  then  made  by  the  method  usually  followed  in 
vulcanite  work.  The  rubber  inlay  is  noted  only  as  a  curious  fact,  and 
is  not  enlarged  upon  or  recommended,  for  its  color  is  not  equal  to  ]>orre- 
lain,  nor  is  its  edge  strength  equal  to  that  of  gold.  As  we  have  luit 
only  other  materials  that  will  ])roduee  better  results,  but  also  materials 
that  can  be  manipulated  in  the  time  required  merely  for  the  vulcanizing 
of  the  rubl)er,  it  does  not  seem  advisable  to  enlarge  upon  a  process  that 
appears  to  have  no  practical  value. 

MAKIX(;    MATIIICES    UPON    MODELS    FOR    PORCELAIX    INLAYS. 

There  are  many  who  take  impressions  of  the  cavities  intended  for 
porcelain  inlays,  which  impressions  are  run  out  in  plaster  or  oxyphos- 
phate  of  zinc.  On  the  models  thus  obtained  the  matrices  are  formed, 
and  the  porcelain  fillings  finished  according  to  shades  selected  when  the 
impression  was  taken.  This  has  the  advantage  of  saving  much  time  for 
the  operator,  as  the  work  of  construction  may  be  done  by  an  assistant 
in  the  laboratory.  As  good  results  are  claimed,  the  process  should  be 
given  a  fair  trial ;  l)ut  on  theoretical  grounds  the  expansion  of  the 
plaster,  or  the  contraction  of  the  oxyphosphate  of  zinc'  used  for  the 
mould  would  tend  to  cause  inaccuracy  in  adaptation  of  the  edge. 
Most  inlay  workers  find  it  sufficiently  difficult  to  get  perfect  adaptation 
when  the  matrix  is  burnished  to  sharp  enamel  edges,  and,  except  in 
labial  cavities,  to  get  the  exact  contour.     Also,  the  colors  often  rc(juire 

^  Wet  oxyphosphate  of  zinc  usually  expands;  dry  oxyphosphate  usually  contracts. 


MAKING  MATRICES  UPON  MODELS  FOB  PORCELAIN  INLAYS.    383 

such  nice  calculation  that  an  assistant,  not  having  seen  the  mouth, 
could  hardly  mix  them  satisfactorily.  While  good  results  have  been 
obtained  by  giving  the  matrices  for  filling  to  an  assistant  especially 
trained  in  the  art  of  fusing  and  mixing  the  porcelains,  thus  proving 
that  such  time-saving  methods  are  practicable,  the  average  dentist 
should  not  attempt  the  art  of  inlays  with  the  idea  of  saving  time ; 
probably  there  will  always  be  sufficient  factors  for  failure  if  he  works 
directly  from  the  tooth  cavity  and  gives  his  entire  personal  skill  to 
the  completion  of  the  filling.  With  porcelain  inlays  the  question  of 
artistic  color  effect  is  paramount,  and  only  through  the  most  subtle 
discrimination  can  the  best  results  be  obtained. 

^  Wet  oxyphosp]iate  of  zinc  usually  expands;  dry  oxyphosphate  usually  contracts. 


CHAPTER    XYI. 

THE  CONSERVATIVE  TREATMENT  OF  THE  DENTAL  PULP— 
DEVITALIZATION  AND  EXTIRPATION  OF  THE  PULP. 

By  Louis  Jack,  D.D.  S. 


As  the  dental  pulp  by  its  supply  of  nutritive  pabulum  maintains 
the  vitality  of  the  dentin  and  increases  the  resisting  power  of  the  tooth, 
it  is  important  when  this  organ  becomes  exposed  to  agencies  which 
threaten  its  destruction,  to  attempt  its  preservation  when  the  condi- 
tions are  favorable  to  that  object.  A  further  reason  for  maintaining 
the  vitality  of  the  dentin  is  that  when  the  pulp  becomes  devitalized  the 
loss  of  cohesive  force  which  occurs  as  a  consequence  leads  sooner  or 
later  to  the  fracture  and  ultimate  loss  of  the  tooth — this  final  result 
being  delayed  in  proportion  to  the  inherent  strength  of  the  tooth  and 
the  period  of  life  at  which  devitalization  takes  place. 

The  treatment  of  teeth  when  the  pulp  has  been  approximately 
reached  by  the  invasion  of  dental  caries  has  been  previously  consid- 
ered (Chapter  VI.).  Here  will  be  set  forth  a  rational  line  of  treatment 
when  the  carious  action  has  encroached  upon  that  organ. 

Normal  Characteristics  and    Pathological   Tendencies  of 

THE  Dental  Pulp. 

The  minute  anatomical  elements  of  the  dental  pulp  are  given  in 
Chapter  II.  The  salient  features  of  these  elements  which  have  to  be 
kept  in  view  in  connection  with  treatment  are — 

(1)  The  minuteness  of  the  apical  foramina,  which  restricts  the  efferent 
circulation  when  the  vascular  phenomenon  known  as  '"'  determination  " 
occurs. 

(2)  The  ultimate  nervous  distribution  immediately  beneath  the  odon- 
toblastic layer,  forming  a  plexus  which  renders  the  whole  surface  of  the 
organ  highly  sensitive  when  the  blood  supply  is  increased  as  the  effect 
of  irritation. 

(3)  The  arrangement  of  the  capillary  circulation  in  loops  which  arise 
from  the  vertical  vessels.  This  relation  of  the  vessels  lessens  the  tend- 
ency to  inflammatory  diffusion. 

25  385 


386  CONSERVATIVE  TPxEATMENT  OF  THE  PULP. 

(4)  Till'  abscnct'  of  lyniplmtics,  wliioli  deprives  the  pulpof  tlie  j^ower 
to  remove  iiiH:niini;itorv  etl'iisions  or  lo  convey  insoliihle  medicaments. 

It  should  he  noted  that  the  judp  in  a  normal  state  is  not  a  hijjhly 
sensitive  organ,  hut  is  rendered  ex(|uisitely  so  hy  the  irritation  from 
external  chemical  and  infectious  intluences  incident  to  its  exj)osure. 
And  it  is  under  all  conditions  so  extremely  impatient  of  compression 
that  a  severe  shock  of  that  kind  renders  recuj)eration  nearly  impossible. 
This  is  probably  due  to  the  liability  of  disconnection  of  the  l)ulp  with 
its  walls  at  some  point  on  account  of  its  feeble  attachment  to  them. 

The  pathological  tendencies  of  the  pulp  under  irritation  are — 

(1)  To  hyj)ercsthesia. 

(2)  To  circumscribed  hyperemia  under  slight  irritation. 

(3)  To  congestion  or  mechanical  hyperemia  under  increased  irrita- 
tion which  terminates  at  length  in  stasis  by  the  restriction  of  the 
circulation. 

(4)  To  proliferation  of  the  deeper  tissues  as  the  result  of  latent  con- 
gestion attended  by  fatty  degeneration  of  cells  and  the  development  of 
dentinal  nodules — pulp  stones. 

An  important  consideration  connected  with  the  treatment  of  the 
pulp  is  the  indication  presented  by  a  state  of  the  teeth  designated  as 
the  "temperature  sense."  This  is  a  variable  condition  with  different 
individuals,  some  being  able  to  apply  the  coldest  water  in  the  mouth 
and  to  crunch  ice  without  pain,  whilst  others  whose  teeth  are  sound  are 
disturbed  if  cool  water  is  brought  into  direct  contact  with  these  organs. 
AVhen  irritation  of  the  pulp  occurs  the  temperature  sense  is  exaggerated 
in  the  individual  tooth.  This  variation  from  the  normal,  as  determined 
by  a  comparative  test  of  the  sound  teeth,  becomes  an  important  diag- 
nostic indication,  as  will  appear  later. 

A  further  pertinent  consideration  bearing  upon  the  various  condi- 
tions of  the  exposed  ])nlp,  as  shown  by  the  symptomatology,  is  here  in 
place.  It  has  already  been  indicated  that  when  the  exj)osure  of  the  pulj) 
to  irritation  has  been  slight — that  is,  where  this  organ  has  been  measur- 
ablv  ])roteeted  from  exterior  influences  by  the  covering  layer  of  incom- 
pletely decalcified  dentin — the  pulp  is  ordinarily  but  slightly  affected. 
When  the  denudation  has  become  complete  and  the  amount  of  pulp 
surface  in  contact  with  the  carious  matter  has  become  considerable, 
and  further,  when  by  the  solution  and  displacement  of  the  carious 
matter  the  influence  of  the  contents  of  the  mouth  is  direct,  the  disturb- 
ances of  the  pulp  become  progressively  increased.  In  the  light  of  pres- 
ent knowledge  of  these  injurious  influences  the  causes  of  their  operation 
must  be  attributed  to  infection  of  the  pulp  by  the  various  minute  organ- 
isms which  have  their  habitat  in  the  mouth.  The  pulp  tissue  becomes 
infected  in  the  degree  to  which  it  is  exposed  and  in  proportion  to  its 


PA THO LOGICAL   TENDENCIES  OF  THE  PULP. 


387 


Fig.  378. 


power  of  resistance  to  the  pathogenic  character  of  tliese  forms  of  life. 
It  ib  axiomatic  that  the  activity  of  inflammatory  processes  is  usually  in 
proportion  to  the  degree  and  the  kind  of  infection.  Therefore  it  must  be 
held  here  as  elsewhere  in  surgical  procedures  that  the  existence  of  infec- 
tive influences  and  their  control  have  to  be  kept  clearly  in  view. 

This  consideration  enables  us  to  understand  the  causes  which  render 
conservative  treatment  inoperative,  in  cases  in  which  there  has  existed 
for  a  considerable  period  the  opportunity  for  active  invasion  of  the  pulp 
by  micro-organisms.  When  these  deleterious  influences  have  long  con- 
tinued, the  deeper  tissues  of  the  pulp,  as  before  stated,  become  involved  ; 
the  chief  factors  producing  the  disturbed  state  eventuate  in  a  suppura- 
tive condition.  This  state  of  the  organ  clearly  indicates  invasion  by  pyo- 
genic germs,  the  inflammatory  processes  attending  this  condition  being 
superinduced  by  the  peculiar  irritation  caused  by  the  infection.  This 
results  in  some  instances  in  stasis  followed  by  gangrene ;  in  other  cases, 
where  the  arterial  tension  has  not  been  great,  in  suppuration.  The  cha- 
racter of  the  suppurative  process,  rarely,  is  a  circumscribed  abscess  of 
the  pulp,  the  more  common  form  being  by 
progressive  and  destructive  ulceration  of 
the  organ. 

Fig.  378  (after  Arkovy)  shows  the 
phenomenon  of  invasion  of  the  pulp  by 
micrococci.^ 

In  the  treatment  of  an  organ  which 
cannot  be  brought  under  ocular  inspec- 
tion, the  chief  guides  to  determine  its  state 
are  the  apparent  conditions — viewed  in  con- 
nection with  the  symptomatology  of  the 
case  under  treatment. 

The  above-stated  anatomical  relations, 
physiological  qualities,  and  pathological  tendencies  have  an  interesting 
bearing  upon  conservative  treatment  of  the  pulp. 

Exposure  of  the  Pulp. — As  an  indication  of  the  tolerance  of  the 
pulp  to  the  approach  of  caries  it  is  a  common  experience  that  after 
solution  of  the  enamel  has  taken  place,  caries  of  the  dentin  proceeds 
until  the  pulp  is  nearly  reached  by  the  destructive  process  with  little  or 
no  signs  of  irritation,  as  evinced  by  pain,  appearing.  It  is  the  excep- 
tion that  even  persons  of  high  nervous  sensibility  are  cognizant  of  the 
influence  of  the  carious  process  upon  the  pulp  previous  to  actual 
encroachment. 

In  the  earlier  stages  of  exposure  the  elements  of  the  organ  involved 

^  In  this  connection  see  Micro-organisms  of  the  Human  Mouth,  by  W.  D.  Miller,  pp. 
293-295. 


Invasion  of  pulp  by  micrococci. 


388  coysi:n\'ATiVE  treatmext  of  the  pulp. 

are  its  pcriplicral  norvo  Hlainonts,  which  are  hypore.sthetic  from  tlie 
hvj)eroniic  stato  of  the  orgiin  immediately  adjacent  to  the  point  of 
encroaelimeiit.  At  this  stage  tlie  judp  lu'eomes  imj)atient  of  cold,  and 
mav  indii-ate  the  nature  of  the  h'sion  by  retiex  |)ain  in  other  brandies 
of  the  trigeminus.  Later  on,  unU'ss  these  conditions  are  subdued  1)V 
treatment  congestion  of  the  organ  takes  phice,  when  objective  symp- 
toms in  the  organ  itself  may  be  elicited.  This  is  shown  by  some  sore- 
ness upon  percussion,  accompanied  by  much  pain  on  the  apj)lication  of 
heat. 

These  indications  point  to  a  greatly  increased  blood  supply.  Dila- 
tation of  the  arterial  vessels  of  the  apical  region  occurs,  and  the  blood 
being  unable  to  enter  at  the  foramen  is  distributed  to  the  peridental 
membrane.  These  manifestations  indicate  that  the  point  of  danger 
has  approached.  Soon  thereafter  congestion  becomes  so  far  estab- 
lished that  prospect  of  successful  conservative  treatment  vanishes. 

When  patients  are  under  frequent  observation  and  have  regular  and 
periodical  care  taken  of  the  teeth  the  pnl[)  exposures  which  occur  should 
be  found  in  the  hyperemie  state,  and  if  })laced  under  treatment  early 
after  the  carious  action  has  approached  the  pulp,  the  jn-ognosis  should 
be  fovorable.  But  when  neglected  eases  appear  the  iiistory  of  which 
is  obscure,  and  where  the  patient  is  forced  to  seek  relief  by  the  occur- 
rence of  objective  symptoms  as  narrated  above,  accompanied  by  local 
pain  and  pulsation,  the  indications  point  to  devitalization  and  extirpa- 
tion as  the  suitable  recourse. 

The  exposure  of  the  pulp  is  often  discovered  in  the  treatment  of 
ordinary  cavities  in  a  somewhat  unexpected  manner,  no  indications 
appearing  until  the  part  is  uncovered  ;  or  a  variety  of  subjective  or 
possibly  objective  indications  may  be  elicited  which  plainly  point  to 
this  condition. 

At  the  commencement  of  the  treatment  to  restore  the  lost  tissue 
in  any  given  carious  tooth,  except  in  very  small  cavities,  the  ])roba- 
l)ility  of  encroachment  upon  the  pulp  should  be  a  supposition,  and  each 
step  should  be  made  with  reference  to  this  probability.  The  destruc- 
tion of  the  dentin  is  frequently  surprisingly  deep,  or  the  cornua  of  the 
pulp  may  be  acutely  pointed  and  liable  to  be  unexpectedly  encountered. 
Therefore,  in  what  may  seem  simple  cases,  cautious  approach  should  be 
made  toward  the  bottom  of  the  cavity. 

Method  of  Opening  the  Cavity, 

The  opening  of  the  cavity  should  be  effected  by  instruments 
which  will  not  easily  enter  it,  and  the  softer  caries  removed  in  a 
manner  Mhich  will  not  induce  pressure  of  the  carious  matter  upon  the 
pulp.     For  this   reason,   in   the   removal   of  the  caries  the  excavation 


METHOD   OF  OPENING   THE  CAVITY.  389 

should  be  first  carried  on  at  the  sides  of  the  cavity,  and  also  along  the 
margin  of  the  cervical  wall  in  approximal  cases.  Then  the  carious 
matter  nearest  the  pulp  should  be  carefully  peeled  off  without  pres- 
sure and  without  irritation.  In  this  manner  a  pulp  may  be  uncov- 
ered and  the  cavity  cleansed  of  carious  matter  without  contact  being 
made  with  the  pulp.     To  do  this  is  the  acme  of  skilful  preparation. 

The  instruments  for  removing  caries  should  be  of  thin  edge,  very 
sharp,  and  always  having  cutting  surfaces  which  are  rounded,  since 
angular  or  square-ended  excavators  are  liable  to  make  exposures  un- 
necessarily. It  is  important  that  the  direction  of  movement  of  the  ex- 
cavators should  be  from  the  cervix  toward  the  occlusal  part — in  other 
words,  by  drawing  cuts  instead  of  pushing  ones.  The  diiference  in  the 
excitement  of  pain  between  these  two  methods  of  cutting  is  surprising, 
and  can  only  be  appreciated  by  those  who  have  experienced  the  com- 
parison upon  their  own  teeth.  The  probable  reason  for  this  is  that  the  force 
of  the  pushing  cut  is  necessarily  greater,  and  this  may  induce  com- 
pression of  the  caries  or  of  fluids  against  the  pulp.  It  causes  more 
pain  at  the  moment,  and  cleansing  in  this  manner  is  followed  by  greater 
after-irritation.  Patients  will  at  the  time  complain  of  reflected  pain 
being  caused  by  incorrect  manipulation. 

It  is  obvious  that  every  mode  of  procedure  which  increases  the  local 
irritation  in  the  preliminary  procedures  of  a  pulp  treatment  must  be 
deleterious  in  its  results.  The  danger  of  making  accidental  exposures 
and  of  forcing  the  instruments  upon  the  pulp  are  increased  under  push 
cutting.  It  is  also  clear  that  the  use  of  burring  instrimients  upon  the 
pulp  wall  of  cavities  is  questionable,  since  the  infliction  of  some  com- 
pression by  excavating  in  this  manner  is  nearly  unavoidable. 

Here  an  interesting  question  appears  :  A  cavity  may  be  sufficiently 
deep  to  cause  an  exposure ;  it  has  been  carefully  cleansed  of  caries,  and 
the  cornua  are  not  apparent.  It  is  then  necessary  to  determine  whether 
there  is  a  real  but  minute  exposure  or  whether  there  is  a  safe  amount 
of  healthy  dentin  to  protect  the  pulp  beneath  the  stopping  material. 

One  method  is  to  cross-hatch  the  cavity  by  a  very  fine  exj^lorer. 
This  is  effected  by  holding  the  instrument  very  lightly  and  passing 
it  gently  over  the  surface  in  parallel  lines  in  two  directions.  If  the 
pulp  has  been  reached,  the  instrument  at  the  point  of  encroachment 
will  lose  its  resistance  or  will  drag  the  point  of  the  cornu,  as  the  case 
may  be. 

While  there  may  be  no  visual  evidence  of  exposure,  the  certainty  of 
it  is  frequently  shown  during  the  preparation  of  the  cavity  or  the  test- 
ing by  a  peculiar  expression  of  the  face  of  the  patient,  different  from 
that  manifested  by  the  cutting  of  the  most  exquisitely  sensitive  dentin. 
This  change  of  the  countenance,  accompanied  by  a  slight  start  of  the 


.390  CONSEJt\'ATIVK   TREATMENT  OE  THE  PVLP. 

features,  may  occur  without  tlic  rcco<:;nitioii  of  pain.  This  indication 
sometimes  appears  previous  to  the  removal  of  all  the  caries;  it  is  then 
probably  caused  by  some  tension  of  the  apex  of  the  cornu  produced 
by  the  disturbance  of  the  carious  dentin. 

The  Diagnostic  Value  of  the  Reaction  of  the  Pulp  to 
Thermal  Tests. 

Allusion  has  been  made  to  the  effects  caused  by  reducinfj  the  tem- 
perature of  the  teeth.  To  make  this  subject  clear  it  is  necessary  to  con- 
sider the  reaction  of  the  dental  pulp  to  thermal  changes  in  its  states  of 
health  and  of  disease. 

The  normal  rate  at  which  the  pul])  of  sound  teetli  reacts  to  cold 
api)lications  varies  with  different  persons  from  22  to  Q)*6  degrees  F.  below 
the  blood  heat,  the  reaction  to  heat  varying  from  20  to  over  55  degrees 
F.  above  the  blood  temperature,  these  tests  being  the  extremes  of  the 
writer's  observations. 

The  degree  of  heat  reaction  may  be  designated  by  the  +  sign  and 
the  cold  rate  by  the  —  symbol.  These  ascertained  extremes  may  be 
taken  as  representing  the  range  of  tolerance  in  any  individual  case. 

The  significance  of  ascertaining  the  noi-mal  rate  of  thermal  irritation 
of  the  teeth  is  im])ortant  in  connection  with  the  treatment  of  any  case. 
When  a  healthy  rate  of  +  144°  -  32°  F.  is  compared  with  one  of  +  124° 
—  76°  F.  this  at  once  is  apparent.  In  the  one  case,  the  range  of  tolerance 
is  112  degrees  ;  in  the  other,  48  degrees.  Hence  it  is  obvious  that  the 
determination  of  the  normal  rate  is  essential  as  a  basis  from  which  to 
consider  the  value  of  the  thermal  reaction  of  any  given  disturbed  pulp. 
It  is  also  evident  that  whore  the  range  of  tolerance  is  considerable  the 
probability  of  favorable  treatment  is  greater  than  when  this  is  small. 
AVhere  the  normal  range  is  found  to  be  below  50  degrees  F.,  unless  the 
other  conditions  are  very  favorable,  conservative  treatment  of  the  pulp 
becomes  questionable. 

The  normal  rate  is  easiest  found  by  exposing  the  lower  incisors  to  a 
continued  discharge  of  water  from  a  small-aperture  syringe.  The  most 
suitable  kind  of  syringe  is  that  having  a  large  aperture  for  charging 
and  a  small  one  for  discharging.' 

The  tests  are  begun  at  a  temperature  of  80°  F.,  reduced  succes- 
sively by  diminutions  of  ten  degrees  until  slight  pain  follows  the  tests. 
The  continuation  of  the  stream  of  "cold  M'ater  is  necessary  to  enable 
the  effect  to  reach  the  pulp  through  the  dentin.  With  some  per- 
sons the  response  is  so  quickly  show'n  as  to  indicate  that  the  dentin 
is  responsive. 

*  The  best  for  the  purpose  is  a  modified  form  of  the  Laskey  syringe. 


REACTION  OF  THE  PULP  TO   THERMAL   TESTS.  391 

A  large  proportion  of  persons  manifest  distress  between  40°  and 
60°  F. 

Intolerance  of  heat  is  determined  in  the  same  manner,  except  that 
it  is  frequently  necessary  to  isolate  the  tooth  by  applying  rubber  dam, 
since  the  gum  usually  begins  to  be  pained  at  130°  F.  In  all  cases  in 
which  the  cementum  is  exposed  isolation  is  required,  since  the  cemen- 
tum  may  react  at  slight  variations  from  blood  heat.  To  secure  exact- 
ness in  any  case  isolation  is  better  than  an  open  test. 

When  disturbance  of  the  pulp  occurs  from  the  extended  progress 
of  caries  the  reaction  of  the  pulp  to  changes  of  temperature  is  usually 
marked,  and  the  variation  from  the  normal  rate  is  indicative  of  the 
degree  of  disorder  of  this  organ.  The  response  occurs  to  temperatures 
both  below  and  above  the  normal  rate.  When  the  irritation  of  the 
pulp  consequent  upon  its  exposure  is  slight,  the  reaction  is  principally 
to  cold,  the  degree  apparently  depending  upon  the  extent  of  the  hyper- 
emia. When  the  reaction  to  heat  is  marked,  congestion  of  the  organ 
is  threatening. 

Disorders  of  the  pulp  appear  to  excite  other  anatomical  elements  of 
the  teeth,  as  is  indicated  by  reaction  to  cold  and  heat  being  more 
immediate  than  is  the  case  with  the  sound  teeth.  A  more  exact 
degree  of  temperature  reaction  may  also  be  secured  when  this  condi- 
tion exists. 

It  is  essential  in  making  tests  that  a  carious  cavity  be  closed  by  a 
pledget  of  wet  cotton.  This  is  sufficient  to  exclude  the  disturbing  effect 
of  the  hypersensitive  dentin,  since  water  is  a  nearly  absolute  non-con- 
ductor. 

Examples  from  practice  to  illustrate  :  1.  Cavity  rate,  +  110°  —80°, 
when  protected  as  above  +  130°  -  60°.  Here  the  normal  rate  was 
+  131°  -  58°.  2.  Cavity  rate,  +  108°  -  90°  ;  normal  rate,  +  134° 
-65°.     3.  Cavity,  +  120°  -  50°  ;  normal,  128°  -48°. 

The  following  table  of  normal  rates  shows  the  variation  between  the 
point  of  heat  reaction  of  the  pulp  and  the  degree  of  its  reaction  upon 
the  abstraction  of  heat  of  different  persons. 


+  152°  —  41° 
+  150°  —  40° 
+  144°  —  48° 
+  144°  —  32° 
+  140°  —  48° 
+  140°  —  46° 
+  140°  —  46° 
+  140°  —  32° 
+  140°  — 56° 
+  134°  —  58° 
+  134°  —  65° 
+  134°  —  60° 


+  133°  —  66° 
+  131°  —  63° 
+  130°  —  55° 
+  130°  —  72° 
+  128°  —  48° 
-f  126°  —  64° 
+  124°  —  76° 
+  124°  —  60° 
+  122°  —  75° 
+  120°  —  72° 
+  118°  —  74*^ 


392  COySICRVATIVJ'J  TREATMENT  OF  THE  PULP. 

The  normal  averages  of  table — 

9  cases  from  +  152°  to  -f  140° 

average  +  143.3°  —  43.2°  =  100°  range  of  tolerance  ; 
7  cases  from  -f  140°  to  +  130° 

average  +  132.3°  —  62.7°  =  69.6°  range  of  tolerance; 
7  cases  from  -f-  130°  to  -f-  118° 

average  +  123°  — 67°  =  56°  range  of  tolerance. 

Occult  Cases  of  Reflected  Pain. 

Cases  difficult  of  diagnosis  t?ometinies  appear  in  wliicli  the  question 
arises  wiiether  the  pain  is  caused  bv  a  liypercsthetic  i>ulp,  by  the  influ- 
ence of  malarial  poisoning,  or  by  a  gouty  condition.  AVhcn  the  origin 
depends  upon  the  two  causes  last  named  the  teeth  arc  not  subject  to 
thermal  irritation ;  also  from  these  causes  the  occurrences  of  pain  are 
not  confined  to  the  evening,  as  usually  is  the  case  with  teeth  in  the 
early  stages  of  disturbance. 

The  stages  of  pulp  exposure  are  divisible  into  three  periods — (1)  of 
quiescence;   (2)  o^ subjective  symptoms,  and  (3)  of  objective  inanifestafiom. 

(1)  Quiescence  may  continue  in  many  instances  for  a  considerable 
period  after  caries  has  reached  the  pulp  where  the  situation  is  such 
that  the  force  of  mastication  cannot  cause  compression  of  the  contents 
of  the  cavity.  Notwithstanding  constant  saturation  of  the  gelatinous 
covering,  and  the  presence  of  the  micrococci  concerned  in  producing 
the  caries  of  the  dentin,  excitement  of  the  pulp  may  not  occur.  The 
fact  should  not  be  overlooked  that  some  persons  escape  odontalgic 
symptoms  notwithstanding  such  progressive  alteration  of  the  pulp  tissue 
takes  place  as  to  result  in  gangrene  of  the  organ. 

( 2)  Usuallv,  however,  after  a  period  of  quiescence  of  a  longer  or  shorter 
duration  there  arises  a  train  of  subjective  disturbances  brought  on  by 
the  continuance  of  chemical  irritation  and  by  the  presence  of  fluids  in 
the  cavitv,  these  influences  becoming  accelerated  as  the  area  of  exposure 
becomes  increased.  The  pain  which  occurs  in  this  stage  is  reflected  to 
one  or  more  branches  of  the  fifth  pair  of  nerves.  Flashes  of  pain 
occur  to  the  teeth  of  the  other  maxilla,  to  the  eye,  or  the  supraorbital 
region,  the  most  common  region  affected  being  the  nerves  of  the  ear, 
pain  in  this  organ  being  probably  the  most  general  form  of  reflection 
which  occurs.  The  exacerbations  take  place  usually  in  the  evening  and 
at  first  entirely  remit  in  the  daytime.  The  pain  in  this  stage  Avill  fre- 
quently pass  away  as  the  pulp  is  relieved  from  pressure  and  chemical 
irritation. 

In  this  stage  the  surface  of  the  pulp  does  not  present  indications  of 
being  inflamed.  From  the  lack  of  continuity  of  the  symptoms  it  is 
a  reasonable  inference  that  the  hyperesthesia  observed  in  this  condition 
is  due  to  impressions  made  upon  the  point  of  encroachment  and  is  con- 


TECHNICAL   TREATMENT  OF  THE   UNCOVERED  PULP.       393 

fined  to  the  nerve  fibrils  distributed  about  the  capillary  loops  involved, 
and  thereby  induces  the  reflected  manifestations,  the  nerve  fibrils  being 
in  this  stage  the  anatomical  element  chiefly  implicated. 

(3)  Objective  symptoms  comprise  those  manifestations  which,  after 
the  subjective  ones  have  continued  for  some  time,  become  localized  in 
and  about  the  affected  tooth.  These  are  :  some  soreness  of  the  peri- 
dental membrane ;  extreme  sensitiveness  to  heat,  accompanied  througli- 
out  with  dull,  heavy  pain  in  the  tooth,  and  at  length  pulsative 
throbs. 

This  order  of  statement  is  the  usual  sequence  in  which  these  indica- 
tions appear.  They  are  the  result  of  the  extension  of  the  disturbance 
to  the  deeper  circulatory  elements  of  the  tissue.  When  this  condition 
appears  on  the  presentation  of  a  case,  or  when  in  the  course  of  the 
treatment  it  becomes  apparent,  the  prognosis  usually  is  rendered 
unfavorable  to  recuperation. 

The  Technical  Treatment  of  the  Uncovered  Pulp. 

Accidental  Exposures. — These,  which  happen  in  the  preparation 
of  cavities,  if  produced  by  clean  (aseptic)  instruments  w^here  compres- 
sion has  been  avoided,  require  but  simple  treatment.  The  pain  is 
relieved  by  the  application  of  tincture  of  calendula  one  part,  to  four  of 
water.  When  the  bleeding  ceases,  the  point  of  exposure  should  be 
antiseptically  dressed  and  capped  in  the  manner  to  be  described. 

If  the  injury  has  been  slight,  the  cavity  may  be  at  once  filled  with 
a  metal,  having  regard  to  the  strength,  the  placement,  and  the  fixation 
of  the  cap  used  to  defend  the  part  from  compression.  Here  the  fixa- 
tion may  be  made  by  covering  the  cap  with  a  broad  block  of  gold  foil ; 
after  adapting  this  to  the  margins  of  the  pulp  wall  of  the  cavity  the 
filling  may  be  proceeded  with.  In  case  of  doubt  a  metal  of  less  con- 
ductivity may  be  used,  such  as  tin  or  amalgam.  A  metal  filling  is 
better  in  these  cases,  since  the  slight  thermal  irritation  tends  to  the 
ultimate  recovery.     (See  Chapter    VI.). 

Treatment  of  Recent  Exposures. — ^When  the  pulp  has  been  fully 
uncovered,  as  previously  described,  the  cavity  should  be  washed  clean 
with  tepid  water,  be  securely  protected  from  the  fluids  of  the  mouth 
with  rubber  dam,  dried,  and  lightly  filled  with  a  pledget  of  lint  sat- 
urated with  a  mild  disinfectant.  On  account  of  the  invasion  of  the 
zone  of  dentin  immediately  beneath  the  caries  by  bacteria  and  micro- 
cocci, it  is  recognized  that  some  means  of  sterilization  must  be  adopted. 
This  being  necessary  in  the  treatment  of  ordinary  cavities,  it  is  evidently 
here  more  demanded.  On  account  of  the  impatience  of  the  pulp  to 
medication  it  is  important  to  be  careful  in  the  selection  of  the  sterilizing 
agent.     The  choice  should  be  between  hydronaphthol,  acetanilid,  and 


304  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

formalin  :  tlic  first  in  the  stn'n<>:tli  of  1  to  .')()()  jjarts  water;  the  second, 
1    to  1200  parts;  the  third,  nitt  stron<>;er  than  l.opereent. 

The  saturated  pledget  of  cotton  may  remain  in  the  cavity  durin";  the 
proeednres  of  tlie  preparation  of  the  dressing;  paste,  the  selection  of  the 
eaj),  etc. 

When  these  preparations  are  complete  the  cavity  should  be  a<«;ain 
dried,  the  drying  being  finished  by  a  few  puffs  of  warmed  air.  The 
point  of  ex])osure  and  the  adjacent  dentin  are  now  touched  with  lint, 
filled  with  carbolic  acid  and  oil  of  cloves,  e(jual  ])arts.  The  effect 
of  this  is  to  coagulate  to  a  superficial  degree  the  point  of  exposure. 
This  practice  is  largely  empirical.  It  may  be  avoided  in  cases  where 
no  disturbance  has  previously  existed  ;  but  where  there  arc  evidences 
of  irritation  it  seems  indispensable. 

The  application  of  carbolic  acid  in  this  manner  should  be  for  a 
moment  only.  As  carbolic  acid  has  a  very  feeble  allinity  for  water  and 
as  the  topical  touch  is  but  momentary,  it  probably  does  not  invade  the 
tissue  to  an  ajipreciable  degree.  It  will  also  be  observed  that  the  com- 
bination possesses  anesthetic  properties. 

The  student  will  not  fail  to  hold  in  view  that  the  treatment  is  appli- 
cable to  cases  in  which  it  is  evident  the  pulp  tissue  is  not  under  much 
irritation.  The  condition  should  be  one  of  hyperemia  of  the  organ  and 
gives  indications  of  this  by  the  existing  hyperesthesia.  Congestion 
should  not  have  taken  place,  neither  should  inflammatory  indications 
exist.  Therefore  the  inference  is  that  after  the  carious  matter  is  removed 
the  surface  of  the  dentin  and  the  point  of  exposure  may  be  sterilized 
and  the  vital  force  of  the  pulj)  be  given  the  opportunity  to  overcome 
whatever  slight  bacterial  invasion  may  have  reached  that  organ.  Here 
the  case  must  rest  upon  the  well-established  fact  that  the  tissues  have 
considerable  power  of  mastering  the  influence  of  non-pathogenic  germs 
as  a  factor  in  the  process  of  recuperation. 

Treatment  of  Old  Exposures. — In  the  conditions  which  exist 
where  denudation  has  taken  place  to  a  considerable  degree  and  where 
irritation  has  long  continued,  the  disturbances  which  have  arisen  in 
consequence  of  the  extension  of  the  disorder  to  the  larger  bloodvessels 
and  the  attendant  alteration  of  most  of  the  anatomical  elements  of  the 
pulp,  the  chances  of  establishing  quiescence  are  slight. 

In  the  earliest  stages  of  objective  disturbances  when  the  constitu- 
tional conditions  are  favorable  an  attempt  may  be  made  at  conservative 
treatment  after  the  inflammatory  conditions  are  subdued  by  antiseptic 
treatment,  accompanied  by  the  use  of  resorbents  and  counter-irritation 
upon  the  gum. 


CAPPING  THE  PULP.  395 

Capping  the  Pulp. 

A  prominent  feature  in  the  conservative  treatment  of  the  pulp  is  the 
means  to  protect  it  from  pressure,  in  agreement  with  the  established 
fact  that  there  is  no  irritation  so  fatal  to  the  normal  functions  of  the 
pulp  as  compression,  and  no  condition  from  which  it  recovers  with  so 
much  difficulty  as  this.  Therefore  all  means  directed  toward  its  con- 
servation must  conform  to  the  necessity  of  preventing  the  least  degree 
of  compression.  The  means  employed  to  prevent  this  form  of  disturb- 
ance have  given  this  method  of  treatment  the  common  appellation  of 
"  capping  the  pulp." 

Another  principle  of  equal  importance  connected  with  the  foregoing 
is  that  the  capping  material  should  be  brought  into  immediate  apposi- 
tion with  the  pulp.  This  is  for  the  reason  that  if  the  least  space  be 
permitted  to  exist  between  the  capping  and  the  exposed  point  this  space 
will  fill  with  effused  fluids,  and  the  putrefactive  changes  which  take 
place  in  these  fluids  induce  the  formation  of  gases  with  consequent 
compression. 

METHOD    OF    CAPPING. 

Various  methods  of  capping  are  practised,  such  as  laying  on  the  part 
disks  of  paper  or  asbestos  rendered  antiseptic  in  various  ways ;  using 
disks  of  paper  coated  on  the  side  to  be  placed  next  the  pulp  with 
"  chloro-percha "  or  other  plastic  matter ;  flowing  over  the  exposed 
point  a  coating  of  oxysulfate  or  oxychlorid  of  zinc,  being  careful  with 
the  latter  to  use  a  formula  of  the  fluid  element  in  which  the  zinc 
chlorid  is  only  in  sufficient  proportion  in  relation  with  the  water  that 
the  union  with  the  zinc  oxid  is  not  active.  In  connection  with  this 
method  it  has  been  common  to  mistakenly  employ  the  strength  of  the 
fluid  which  is  used  when  the  formula  is  adapted  for  temporary  fillings. 
When  this  method  is  used  the  coating  is  flowed  over  or  laid  in  a  cap  on 
the  pulp,  and  when  somewhat  "  set "  the  cavity  is  temporarily  filled 
with  a  more  resistant  material  laid  upon  it  with  great  care. 

With    all    the    precautions    which    may    be    taken    these   dressings 
are  somewhat  complicated  and  are  not  applicable  to  small  cavities  or 
those  difficult  of  access.     In  these  cases  the 
writer  has  generally  depended  upon  the  use  Fig.  379, 

of  a  dressing  composed  of  carbolic  acid  and     ^^ 
oil  of  cloves  equal  parts  combined  with  zinc      ^p  ^0  w 

oxid    to    form  a  plastic    paste  of  such   consist-  Weston's  dental  cavity  caps. 

ence  that  when  it  is  laid  upon  the  pulp  it  will 

yield  as  it  is  adapted  to  the  part,  without  producing  pressure,  and  will 
flow  out  around  the  margins  of  the  metal  cap  when  this  is  used  to  con- 
vey the  dressing. 

^  Weston's  caps  should  have  the  hole  on  the  surface  closed. 


396 


CONSERVATIVE  TREATMENT  OF  THE  PVLP. 


TIk'  cunnxv-^ition  ot"  the  dre.^sing  is  based  iijum  tlie  considerations 
that  the  menstruum  is  antiseptic,  and  possesses  some  anesthetic  vahic. 
It  also  remains  unchanj^ed  within  the  space  and  in  time  becomes,  from 
the  dissipation  of  the  menstruum,  somewliat  firm  in  its  cliaracter.  The 
therapeutic  action  of  the  menstruum  wlien  combined  with  tlie  zinc  oxid 
is  mild,  and  is  employed  for  the  reason  that  it  is  slowly  given  uj)  by  the 
oxid,  and  therefore  makes  an  accejitable  dressing. 

The  Cap. — In  all  cases  where  metal  fillings  are  selected  it  is  CvSsential 
to  use  a  metal  cap.  The  methods  where  this  is  used  are  simpler  and 
better  under  contntl  than  when  dressings  arc  made  without  this  appli- 
ance. The  reason  for  this  is  that  the  avoidance  of  compression  is  more 
certain. 

The  caps  are  best  when  made  of  aluminium,  for  the  reasons  that  this 
metal  is  a  resistant  material  and  caps  of  it  are  easily  formed. 

When  the  outer  filling  is  to  be  of  gutta-percha  or  of  the  mineral 
cements,  caps  may  be  formed  of  concave  disks  of  pure  tin.  The  tin 
and  aluminium  caps  are  stamped  from  the  plate  by  the  hollow  ])un(;hes 
of  the  hardware  shops,  by  which  means  various  sizes  of  round  and 
elliptical  ones  may  be  made.  The  effect  of  punching  them  upon  the 
end  of  a  block  of  wood  gives  the  suitable  concavity  to  meet  the  recpiire- 
ments.  For  ordinary  purposes  they  should  be  quite  thin,  but  when 
gold  fillings  are  made  over  them  the  thickness  and  the  concavity  should 
be  such  as  to  enable  them  to  sustain  the  force  applied.  In  cases  where 
there  are  indications  of  approaching  congestion,  or  where  it  is  probable 
that  the  ex])osure  is  not  recent,  the  dressing  should  have  added  to  it  a 
portii»n  of  guaiaeoeain. 

Placing-  the  Cap  in  Position. — Placing  the  cap  in  position  i.s  a  step 
in  the  treatment  requiring  care.  It  should  be  assured  that  it  is  of  suf- 
ficient size  to  pass  well  beyond  the  borders  of  the  ex- 
l)osed  organ,  and  in  the  approximal  cavities  it  should 
cover  the  pulp  wall  of  the  cavity  without  intruding 
upon  the  marginal  walls.  If  there  is  a  single  exposure 
it  shoidd  be  round;  if  two  cornua  are  exposed,  either 
two  caps  shoidd  be  laid  or  one  oval  one  employed,  as 
may  best  suit  the  case.  In  molars,  usually,  where  two 
points  are  exposed,  two  caps  are  generally  best ;  in  the 
bicuspid,  (jue  oval  one  under  the  same  circumstances. 
The  cap  should  be  inserted  edgewise  in  such  manner 
that  as  it  is  laid  in  ])lace  the  excess  of  dressing  may  flow 
out  at  the  margin  toward  the  operator.  This  is  to  prevent  undue 
pressure,  and  to  avoid  air  being  included  beneath  the  dressing,  which 
would  prevent  com})lete  apposition  of  the  dressing  with  the  pulp. 
In  cases  of  easy  access  the  cap  may  be  laid  in  ])laee  with  fine-pointed 


Fio.  380. 


CAPPING    THE  PULP.  397 

pliers — notably  the  Bogue  pliers  ;  but  in  the  majority  of  instances  it  is 
preferable  to  previously  coat  the  convex  side  of  the  metal  with  wax, 
when,  with  an  instrument  adapted  to  the  case,  it  may  be  carried  into 
position  and  then  placed  in  the  manner  described.  It  should  next 
be  pressed  into  position  with  sufficient  force  to  bring  the  margins  in 
contact  with  the  dentin.  Any  excess  of  dressing  should  be  taken  away 
by  light  touches  of  an  excavator,  and  when  the  cavity  is  to  be  filled 
temporarily  it  is  better  to  fix  the  cap  in  place  by  flowing  over  it  a  little 
chloro-percha,  which,  when  dried,  prevents  disturbance  of  its  position 
in  the  filling  procedure. 

Care  should  be  taken  that  when  the  pulp  is  found  exposed  in  a  de- 
pression, as  occurs  sometimes  in  the  molars,  this  depression  should  be 
filled  nearly  or  quite  to  a  level  with  the  floor  of  the  cavity  by  taking  a 
little  of  the  dressing  upon  a  suitable  instrument  and  carefully  filling 
this  point ;  otherwise,  when  the  cap  is  placed,  the  paste  may  not  find  its 
way  into  contact  with  the  pulp. 

At  the  moment  of  placing  the  cap,  as  the  paste  is  yielding  under  the 
gentle  pressure  of  forcing  the  edges  of  the  cap  into  contact  with  the 
dentin,  a  little  pain  will  sometimes  be  observed ;  but 
unless  the  paste  is  too  stiff  no  compression  of  the  pulp  ^^^  ^'^^• 

should  be  caused. 

Filling  the  Cavity. — Whether  the  cavity  shall  be 
filled  temporarily  or  permanently  depends  upon  the 
prognosis.  This,  as  will  be  perceived,  is  based  upon 
the  constitutional  conditions  and  the  state  of  the  pulp       „ 

i^      -I^  Cap  m  position. 

at  the  time  of  treatment. 

For  those  of  small  experience  in  this  line  of  treatment  it  would  not 
be  safe  to  attempt  the  permanent  stopping  of  the  cavity,  except  in  acci- 
dental exposures  and  in  cases  where  the  history  of  no  previous  dis- 
turbance can  be  elicited  and  where  the  thermal  reaction  is  slight.  Even 
in  the  latter  class  it  is  generally  best  to  delay  permanent  closure  by  a 
conductor  of  heat  until  after  an  experience  of  a  year  or  more  with  a 
non-conducting  stopping.  At  the  end  of  this  time  the  filling  may  be 
nearly  all  removed,  care  being  taken  not  to  disturb  the  cap,  when  with 
suitable  precaution  a  metallic  filling  may  be  inserted. 

In  the  majority  of  instances  it  is  safest  to  fill  the  cervical  part  with 
gutta-percha  stopping,  carrying  the  material  over  the  cap,  and  then  to 
complete  the  filling  with  zinc  phosphate.  In  this  way,  with  an  occa- 
sional renewal  of  this  temporary  w^ork,  cases  may  be  carried  forward 
from  ten  to  fifteen  years. 

They  may,  however,  be  closed  permanently  and  safely  after  an 
experimental  trial  of  five  years  where   no  irritation  has  appeared. 

In  many  instances  recovery  takes  place  by  secondary  deposits  of 


3J)8  CONSERVATIVE   TREATMEyT  OF  THE  FULP. 

dentinal  tissnc  the  exact  character  of  which  has  not  been  made  out. 
Tile  writer  lias  observed  a  multitude  of  cases  in  practice  when  the  open- 
int;  at  the  point  of  exjiosure  has  l)ecome  occluded  by  bony  tissue.  In 
some  instances  this  has  oceurred  in  two  years,  in  others  after  lonjicr 
periods.  In  one  instance  a  lateral  incisor  became  i)rotectcd  by  this 
formation,  but  in  consequence  of  mistaken  diagnosis  of  another  condi- 
tion eausint;  pericementitis,  a  drill  was  ])asscd  tliroutdi  the  new  tissue 
to  the  living  pulp.  This  new  opening  healed  again.  Ju  the  same  mouth 
another  incisor  also  rccui)erated  in  the  same  period. 

In  some  cases  when  entire  quiescence  has  been  maintained  for  many 
vears  the  pulp  will  be  found  not  to  have  undergone  any  ])rotective 
changes. 

It  is  not  remarkable,  however,  that  pulps  may  remain  in  a  state  of 
quiescence  for  a  long  period,  when  it  is  considered  that  in  slowly- 
advancing  caries  the  pulp  will  often  be  exposed  for  a  long  time  without 
the  occurrence  of  any  signs  of  irritation,  unless,  by  the  position  of  the 
mouth  of  the  cavity,  the  pulp  has  liecn  subjected  to  the  pressure  of 
food. 

It  mav  be  concluded  that,  whether  the  ])ulp  becomes  ])rotected  by 
secondarv  deposits  or  acquires  complete  quiescence,  conservative  treat- 
ment in  these  cases  has  considerable  advantage  over  immediate  devital- 
ization. Still,  in  this  connection  in  order  to  avoid  embarrassments  the 
necessitv  exists  for  careful  selection  of  subjects  to  be  treated  in  this 
manner,  and  also  for  proper  analysis  of  the  apparent  condition  of  the 
pulp  itself.  To  aid  in  this  discrimination  the  following  summary  of 
conditions  should  be  held  in  mind  : 

(a)  Where  no  previous  observable  disturbances  can  be  elicited. 

(6)  Where  the  tooth  has  been  impressed  only  by  the  application  of 
low  temperature. 

(c)  Where,  in  addition,  reflected  pain  in  related  parts  has  been 
observed. 

(d)  Where  the  tooth  has  become  much  subject  to  impressions  by 
heat. 

(e)  Where  continued  objective  disturbances  appear,  such  as  soreness 
to  touch,  or  local  pain  of  spontaneous  character  accompanied  by  pulsa- 
tion. 

Classes  a,  b,  and  c  may  be  considered  as  amenable  to  treatment,  and 
also,  problematically,  class  d  if  taken  early.  Class  e  must,  in  view  of 
the  principles  stated  in  this  section,  be  eliminated  from  the  field  of  con- 
servative treatment ;  and  where  cases  in  the  other  divisions  apparently 
amenable  subsequently  take  on  disorders  coming  within  this  classi- 
fication they  usually  have  passed  beyond  the  reach  of  palliative  treat- 
ment. 


CAPPING   THE  PULP.  399 

It  is  important  here  to  consider  the  influence  of  the  physical  endow- 
ments of  the  patient  upon  the  conservative  treatment  of  the  pulp.  For 
some  persons  this  treatment  is  followed  by  the  happiest  results ;  no 
intolerance  of  the  operation  appearing,  and  even  cases  somewhat  un- 
promising doing  well.  Again,  with  others,  any  case,  however  simple, 
goes  down  the  scale  to  class  e  in  spite  of  every  care. 

The  first  constitutional  condition  favorable  to  success  is  that  of 
soundness.  As  to  what  are  called  temperamental  indications,  when  the 
subject  is  of  good  health,  the  lymphatic  should  alone  be  excluded  and 
more  particularly  the  bilio-lymphatic.  These  latter  do  not  respond  to 
pulp  treatment  in  any  conditions  which  occur  to  them  ;  and  in  reference 
to  their  exposed  pulps  the  probabilities  are  that  in  the  sluggish  condi- 
tion of  the  parts  involved  the  organ  is  early  invaded  by  bacteria,  and 
such  changes  have  quickly  taken  place  in  the  anatomical  elements  of 
the  pulp  as  to  render  all  chances  of  successful  treatment  valueless.  The 
most  promising  cases  are  those  for  persons  of  active  temperaments,  with 
good  circulation,  thin  skins,  healthy  gums,  and  limpid  oral  secretions. 

After-treatment. — It  is  not  unusual  for  classes  a,  6,  and  c  to  require 
after-treatment.  For  this  reason  close  observation  for  some  time  should 
be  maintained.  It  is  presumed  that  the  judicious  operator  has  made 
careful  selection  of  the  cases  to  be  conservatively  treated  and  that  he 
will  early  decide  from  an  analysis  of  the  evident  conditions  whether  the 
prognosis  is  promising  or  not.  As  previously  indicated,  some  of  the 
apparently  favorable  cases  will  not  yield  to  treatment  for  the  reason 
that  the  actual  condition  of  the  pulp  may  not  be  made  out.  Part  of 
the  difficulty  here  is  occasioned  by  the  indefinite  character  of  the  state- 
ments of  the  patient,  who  should  in  all  cases  be  instructed  to  return  for 
consultation  if  painful  response  to  cold  appears  or  if  reflected  pain 
should  occur.  If  these  conditions  supervene,  it  is  a  sign  of  needed  care 
to  avert  increasing  disturbance. 

A  most  marked  form  of  reflected  pain  is  felt  in  the  ear,  and  this 
frequently  occurs  previous  to  the  aggravation  of  the  temperature  reac- 
tions. So  much  importance  should  be  attached  to  this  symptom  of 
pulp  disturbance  that  the  first  question  asked  a  patient  appearing  with 
pain,  or  on  approaching  a  suspected  pulp,  is.  Have  you  had  any  pain 
in  the  ear  of  that  side?  As  reflection  to  the  ear  often  occurs  in  advance 
of  similar  pain  in  other  branches  of  the  fifth  pair,  it  becomes  important 
to  maintain  close  observation  of  this  in^lication.  In  this  state,  sedation 
combined  with  counter-irritation  is  required. 

In  any  case  where  the  tooth  has  been  impressed  by  cold,  either  before 
the  treatment  or  afterward,  an  application  should  be  made  to  the  gum 
over  the  tooth,  of  tincture  of  aconite  root  two  parts,  chloroform  one 
part.     The  mode  of  application  is  important.     A  pledget  of  cotton  or 


400  CONSKRVATlVh'   TRKATMEyT  OF  THE  PULP. 

muslin  to  cover  an  ari'a  of"  oiic-lialf  by  tliroe-lourtiis  ol'  an  inch  should 
l)c  tilled  with  the  prescription,  then  squeezed  out  nearly  to  dryness  between 
folds  of  a  napkin  t<»  prevent  an  excess  flowing  over  the  mouth  and  with 
the  saliva  entcrin<r  the  fauces,  to  which  it  is  extremely  irritating  as  well 
as  unnecessarily  medicating  the  i)aticnt.  Before  the  ])lcdget  is  applied 
the  surface  of  the  gum  should  be  cleansed  of  the  coat  oi'  mucus  cover- 
ing it,  otherwise  the  remedy  will  fail  to  come  in  contact  with  the  mem- 
brane. It  is  e(|ually  iini)ortant  that  dryness  of  the  surface  be  secured. 
This  application  should  be  maintained  for  from  twelve  to  fifteen  seconds. 
If  allowed  to  remain  too  long  uj)on  the  part,  vesication  takes  place. 
The  general  after-treatment  consists  in  the  repeated  application  of  aco- 
nitum  as  above  directed,  the  repetitions  not  being  made  at  the  same  point 
more  frequently  than  at  intervals  of  forty-eight  hours.  When  it  is 
desired  to  increase  the  counter-irritation,  the  gum  may  be  scaritied  very 
superficially  by  quick,  light  movements  of  a  small  scalpel.  The  patient 
should  be  instructed  to  avoid  subjecting  the  tooth  to  extremes  of  tem- 
perature in  either  direction.  The  control  j)eriod  of  conservatively 
treated  cases  is  usually  within  the  first  fortnight  after  the  capping. 

It  is  important  that  treatment  be  given  at  the  beginning  of  the  dis- 
turbance", when  a  few  applications  may  suffice.  Neglected  cases,  from 
the  tendency  to  pulp  disorders,  arc  liable  to  pass  beyond  the  curative 
stage. 

The  interesting  phenomenon  is  frequently  observed  that  when  the 
heat  rate  rises  the  pulp  at  first  becomes  more  intolerant  of  cold.  In 
case  the  pulp  continues  to  respond  to  the  remedy  the  range  of  tolera- 
tion should  increase  in  both  directions. 

Examples:  Xo.  1,  W.  H.  J.,  +  108°-73°  ;  112^-76°;  +120° 
-74°;  124° -74°;  128° -67°;  +  130°  -  66°.  No.  2,  I.  A.  W., 
+  120°  -  84°  ;  +  120°  -  86°  ;  128°  -  86°  ;  +  124°-76°  ;  +  134°-70°  ; 
+  140°  -  67°  ;  +  142°  -  66°  ;  -f  142°  -  64°. 

It  sometimes  becomes  necessary  to  open  the  cases  and  recap.  'J'his 
usually  occurs  when  in  revii'wing  the  case  it  is  considered  that  some 
oversight  has  befallen.  There  may  have  been  two  exposures.  The 
cap  may  not  have  completely  covered  the  exposed  part.  There  may 
have  been  some  compression  from  forcing  the  ca}),  or  it  may  have  been 
displaced  diu'ing  the  after-])rocedures. 

Most  careful  records  of  all  cases  should  be  kept,  with  a  relation  of 
the  condition  and  of  the  controlling  symptoms.  These  records  should 
be  methodically  preserved  in  a  book  kept  for  this  purpose.  Should  sub- 
sequent irritation  occur,  a  new  diagnosis  may  be  formed  from  the  recorded 
facts  and  the  new  conditions.  The  record  of  conservatively  treated  pulps 
should  be  carried  forward  to  the  examination  chart  at  each  recurring 
periodic  examination  of  the  teeth.     It  is  better  that  they  be  marked  in 


CALCIFIC  CHANGES  IN  THE  PULP. 


401 


symbol  with  red  iuk,  to  prevent  the  unnecessary  removal  of  temporary 
fillings  and  to  explain  the  reason  for  their  presence  and  thus  avoid  the 
accident  of  unnecessarily  uncovering  the  pulp  in  such  cases. 


Calcific  Changes  in  the  Pulp  as  related  to  the  Operation 

OP  Pulp  Capping. 

When  loss  of  substance  takes  place  slowly,  either  by  carious  action 
or  by  attrition,  a  notable  calcific  grow^th  takes  place  in  the  pulp  cham- 
ber opposite  to  the  point  of  waste  in  the  direction  of  the  radiant  course 

Fig.  382. 


Secondary  dentin,  resulting  from  irritation  of  the  dentinal  fibrils  by  caries  (Black).  A,  Diagram 
of  an  incisor  having  a  decay  in  the  labial  surface,  a,  and  a  deposit  of  secondary  dentin  at  6. 
The  point  from  which  the  illustration  B  is  taken  is  shown  by  c.  B,  Illustration  of  the  tissue 
of  the  secondary  deposit  in  A:  a,  primary  dentin ;  h,  secondary  dentin ;  c,  seems  to  be  a  blood- 
vessel that  has  become  calcified ;  d,  an  irregular  fault  having  some  resemblance  to  the  laeunse 
of  bone ;  e,  pulp  chamber.  It  will  be  noted  that  there  are  irregular  deposits  of  granular  matter 
in  the  substance  of  the  secondary  dentin,  and  that  the  tubules  wind  about  them. 

of  the  tubules  (see  Fig.  382).  If  the  loss  of  substance  from  the  ex- 
terior progresses  with  sufficient  slowness  encroachment  upon  the  pulp 
does  not  take  place.  The  pulp  chamber  may  become  obliterated  by  the 
progressive  deposition  of  calcific  matter,  which  has  the  designation  of 
secondary  dentin. 

The  morphological  character  of  the  secondary  deposit  is  histologically 
irregular,  being  frequently  of  mixed  character,  presenting  some  of  the 
characteristics  of  dentin  and  also  containing  cemental  cells  with  radiant 
and  anastomosing  canaliculi.  For  this  reason  deposits  have  been 
designated  as  osteo-dentin. 

In  the  earlier  years  of  life  opportunity  does  not  oiFer  to  study  these 
changes  of  structure,  as  the  usual  progress  of  caries  is  too  rapid,  but  in 
advanced  life  they  are  common,  it  being  not  infrequent  to  find  complete 
26 


402 


CONSERVATIVE  TREATMENT  OF  THE  PULP. 


ohliti'i'atioii  of  the  ]>iil|)  cavity  as  well  as  of  the  canal  of  tlic  root  (see 
Fig.  383).     In  some  instances  nodules  of  calcific  material  aj)p('ar  un- 

Fi(i.  383. 


Calcification  of  the  dental  pulp  (Black).  At  A  is  shown  the  outline  of  a  lower  molar  with  a  cavity 
at  b.  Tlie  pulp  chamber  is  much  reduced  in  size  and  filled  with  calcific  material,  as  shown  in 
B.  a,  a  large  granular  mass  of  calcific  material,  which  is  very  transparent  but  finely  granular. 
A  very  few  irregular  lines  are  seen  in  the  centre,  which  slightly  resemble  dentinal  tubes;  b, 
an  erratic  growth  of  irregularly  formed  and  unusually  transparent  dentin;  c,  line  of  the 
growth  of  dentin  from  the  floor  of  the  pulp  chamber:  the  growth  from  other  directions  is  so 
perfectly  regular  as  to  leave  no  markings;  d,  margin  of  the  cavity  of  decay;  c,  a  bundle  of 
cylindrical  forms  of  calcific  material  extending  down  into  the  root  canal.  These  extended  to 
the  apex  of  the  root. 

attached  to  the  walls  of  the  pulp  cavity  (Fig.  384).     These  increase 
sometimes  by  external  development  and  in  other  cases  by  the  coalescence 

Fig.  384. 


A,  Outline  of  a  lower  molar,  with  a  large  carious  cavity  at  a ;  b,  pulp  chamber.  The  shaded  por- 
tion, c,  was  occupied  by  cylindrical  calcifications.  B,  Illustration  of  the  cylindrical  calcifica- 
tions.   X  100.    (Black.) 

of  several  contiguous  nodules.     Again,  several  nodules  inhabiting  the 
pulp  chamber  may  increase  in  size  without  becoming  fused,  and,  accora- 


CALCIFIC  CHANGES  IN  THE  PULP.  403 

modating  themselves  to  each  other  as  development  progresses,  they  at 
length  completely  fill  the  cavity,  from  which  they  are  severally  removed 
with  great  difficulty. 

It  is  remarkable  that  while  in  some  instances  pulp  nodules  become 
the  cause  of  producing  violent  pain  by  their  pressure  upon  the  nerves 
of  the  pulp,  in  the  majority  of  cases  substitution  of  the  normal  tissue 
takes  place  until  nearly  complete  occlusion  of  the  pulp  cavity  is  affected 
without  the  occurrence  of  pain. 

Small  pulp  nodules  are  not  infrequently  found  in  pulps  otherwise 
perfectly  normal,  but  generally  they  are  evidence  of  continued  irritation 
of  a  mild  form  usually  attending  the  progressive  slow  advancement  of 
caries  of  the  tooth.  But  this  is  not  necessarily  the  case,  since  some  of 
the  most  violent  attacks  of  dental  neuralgia  have  arisen  from  the  pres- 
ence of  nodules  in  perfectly  sound  teeth. 

The  diagnosis  of  the  existence  of  pulp  nodules  as  the  cause  of  pulp 
irritation  is  not  easily  made  out.  The  determination  of  the  condition 
usually  can  be  reached  only  by  the  process  of  exclusion.  As  they  do 
not  occur  early  in  life  while  the  teeth  are  undergoing  ordinary  develop- 
ment, they  may  be  looked  for  only  after  middle  life.  The  pain  is  dull 
and  reflected,  and  the  paroxysms  are  frequent.  There  is  sensibility  to 
cold,  and  rarely  pain  appears  on  percussion.  When  the  teeth  are 
sound,  the  disturbing  one  will  usually  be  determined  by  the  tem- 
perature tests. 

An  important  differentiation  from  the  usual  irritation  of  ordinary 
pulp  disturbance  from  exposure  or  the  thermal  irritation  caused  by  the 
approximation  to  the  pulp  of  large  metal  fillings,  is  that  the  disturbance 
from  nodular  irritation  is  not  rapidly  progressive  and  that  the  irritation 
may  continue  without  marked  exacerbations  or  subsidence  for  consider- 
able periods. 

Treatment  is  useless  which  does  not  include  drilling  to  the  pulp  and 
devitalizing  it.  The  difficulties  involved  in  treatment  by  devitalization 
are  liable  to  be  attended  by  great  pain,  since  when  the  pulp  chamber  is 
much  occupied  by  nodules  the  action  of  the  devitalizing  agent  has  not 
free  course.  In  these  cases  the  remains  of  the  pulp  between  the  nodules 
and  the  walls  of  the  chamber  are  attenuated,  and  when  irritated  by  the 
arsenous  acid  give  expression  to  an  excessive  degree  of  pain.^ 

The  Influence  of  Pulp  Exposure,  and  the  Effect  of  Conservative  Treat- 
ment of  the  Pulp  upon  Calcific  Depositions. — Allusion  has  been  made 
to  calcific  deposits  occurring  on  the  walls  of  the  pulp  chamber  as  the 
result  of  peripheral  irritation.  Here,  as  stated,  these  accretions  only 
occur  when  the  degree  of  irritation  is  slight  and  of  long  continuance. 
The  examples  of  this  which  have  been  given  in  dental  literature  are 

^  For  the  form  and  extent  of  nodular  calcification  see  American  System  of  Dentistry. 


404  COXSKRVATIVE  TRRATMKST  OF  THE  I'VLP. 

cuiU'liisivc  as  to  the  ability  ot"  tlif  [>ulp  at  all  stai:;('s  of"  its  cxistonco  to 
take  on  this  action  wlu'n  the  conditions  are  as  stated.  On  the  contrary, 
when  the  distnrbanccs  are  active  the  formation  of  calcific  tleposits  on 
the  walls  of  the  pnlp  chamber  do  not  take  })lace,  or  if  in  the  earlier 
progress  ttf  decay  they  have  commenced,  as  the  progress  of  the  destrne- 
tive  action  apj>roaches  the  pnlp  this  change  is  snspendcd,  and  in  some 
instances  resorption  of  the  secondary  deposit  takes  ])lace. 

It  is  apparently  in  this  manner  that  the  jnilj)  becomes  (kMindcd  nudcr 
the  influence  of  thermal  or  traumatic  irritation  in  cases  in  which  there 
was  no  evidence  of  exposure  at  the  time  of  the  preparation  and  filling 
of  the  cavity.  This  result  would  appear  to  l)e  related  to  the  principle 
that  secondary  structures  and  tissue  of  repair  are  liable  to  resorption  as 
the  result  of  irritation  or  disturbances  of  nutrition. 

The  frequent  occurrence  of  secondary  dentin  foll(»wing  the  conserva- 
tive treatment  of  the  pulp  and  in  some  instances  occurring  spontaneously 
over  expo.sed  pulps,  raises  important  considerations  connected  with  the 
subject.  The  writer  has  had  many  instances  come  under  his  observation 
in  which  secondary  dentin  has  obliterated  exposures,  both  in  his  own 
cases  and  in  those  of  others. 

The  influence  of  the  tendency  to  nodular  deposits  upon  the  results 
of  conservative  treatment  does  not  appear  to  be  detrimental  unless  the 
pulp  chamber  becomes  largely  filled  with  them.  The  pnlp  at  the  period 
of  life  when  calcific  de])osits  usually  take  place  is  not  so  sensitive  as  it 
is  at  an  earlier  age,  and  therefore,  indess  senile  conditions  appear  to  be 
present  or  imminent,  the  existence  of  such  deposits  should  not  be  inim- 
ical to  the  preservation  of  the  pulp.  The  writer,  who  has  had  fre(|uent 
cases  of  pulp  devitalization  after  conservative  treatment,  has  rarely  ob- 
served "  pwlp  stones  "  in  these  cases. 

It  is  an  important  consideration  that  when  calcific  deposits  take 
place  beneath  fillings  where  the  l)ulp  has  been  nearly  exposed,  or  where 
they  have  followed  conservative  treatment  of  the  pulp,  they  are  liable 
to  resorption  on  the  occurrence  of  irritation  of  the  pulp  from  any  cause 
which  brings  on  an  increased  blood  supply.  This  is  more  remarkable 
since  there  are  no  lymphatic  vessels  in  the  pulp.  This  change  can  occur 
only  by  the  development  of  osteoclasts  on  the  surface  of  the  pulp. 
Of  this  development  there  have  been  several  recorded  instances 
where  the  dentin  has  suffered  resorption  until  the  enamel  has  been 
encroached  upon  by  the  process  of  denudation,  and  when  favorable 
conditions  were  established  a  deposition  or  formation  of  secondary 
dentin   has   occurred. 


EXTIRPATION  OF  THE  PULP.  405 

Extirpation  of  the  Dental.  Pulp. 

The  removal  of  the  pulp  is  necessary  when  there  has  existed  such  a 
degree  of  disturbance  of  this  organ  as  to  render  conservative  treatment 
inadmissible.  Also  when  the  pulp  has  become  denuded  by  attrition  or 
by  fracture  of  the  crown  and  also  where  the  roots  are  required  to  serve 
the  purpose  of  bases  for  the  attachment  of  artificial  crowns  and  abut- 
ments of  bridges. 

To  facilitate  the  immediate  extirpation  of  the  pulp  the  employment 
of  cocain  has,  within  a  recent  period,  come  into  use  to  effect  anesthesia 
of  this  structure.  For  this  purpose  cocain  hydrochlorid  is  dissolved  in 
a  solution  1  to  1000  of  adrenalin — 1  grain  to  5  minims  of  this  strength 
being  of  sufficient  activity. 

The  application  may  be  effected — 

(1)  By  instillation. 

(2)  By  the  pressure  method. 

(3)  By  cataphoresis. 

The  choice  of  method  depends  upon  the  situation,  the  direction  of 
approach,  and  the  state  of  the  organ. 

It  is  necessary  in  each  case,  by  either  method,  as  a  preliminary,  that 
the  carious  matter  be  removed  and  the  tooth  and  such  adjacent  ones  as 
may  be  necessary  be  enclosed  in  a  rubber  dam  to  prevent  the  escape 
of  the  solution  into  the  mouth. 

Instillation  is  more  applicable  to  exposures  by  attrition  or  fracture, 
and  where  there  is  direct  approach  or  where  the  rubber  dam  cannot  be 
applied  ;  also  for  the  obtunding  of  a  remnant  of  pulp  in  canals  where  the 
pressure  method  or  cataphoric  applications  have  not  reached  the  apices 
of  roots. 

To  effect  instillation  a  drop  of  the  solution  is  placed  upon  the  exposed 
pulp,  and  after  a  moment  is  lightly  pricked  into  the  surface  of  the  organ. 
This  conveys  the  solution  into  the  tissue;  as  pain  is  manifested  the 
instillation  is  interrupted  and  successively  reapplied  as  it  may  be  tol- 
erated. In  most  single-rooted  teeth  a  few  minutes  is  sufficient  to  permit 
the  complete  removal  of  the  pulp.  If  the  approach  is  direct  or  can  be 
made  so,  the  extirpation  is  easily  effected  with  a  Gates-Glidden  drill  of 
proper  size  for  the  case. 

The  Pressure  Method. — This  consists  of  laying  over  the  exposed  sur- 
face of  the  pulp,  after  it  is  carefully  and  broadly  uncovered,  a  small  piece 
of  amadou  (spunk)  saturated  with  a  solution  of  cocain  in  either  adren- 
alin solution,  .001,  absolute  alcohol,  or  chloroform.  The  cavity  is  then 
closed  with  a  piece  of  unvulcanized  rubber.  The  next  step  is  to  effect 
pressure  through  this  directly  toward  the  pulp  with  a  broad  instrument 
so  adapted  in  size  that  it  will  not  meet  with  impediment,  and  yet  not  so 


406  t'USSERVATIVE  THE  ATM  EST  OF  THE  PULP. 

>\\yA\  as  to  t'xt'rt  force  U[)on  tlu^  center  (»!'  the  riil)l)cr.  The  degree  of 
[nvssure  should  at  first  he  slight,  and  be  gradually  increased  as  the  cocain 
exerts  its  effect  upon  the  pulp.  'I'he  fctri'c  is  exerte<i  in' successive  steps, 
diminishing  when  j)ain  follows,  hui  maintained  until  the  sensation  ceases. 
At  length,  when  no  pain  is  produced  hy  excessive  ])ressure,  the  rubber  and 
>punk  are  removed,  when  the  pnl[)  is  innnediately  removed  by  the  usual 
means.    This  operation  is  done  cpiickly,  to  avoid  the  return  of  sensitivity. 

Those  who  pursue  this  plan  state  that  it  })roduces  nearly  uniform 
results  and  enables  the  canal  and  pulp  chamber  to  be  filled  immediately. 

The  indications  are  that  the  cocain  overcomes  the  sensitivity  of  the 
surface  of  the  pidp,  and  that  pressure  paralyzes  the  tissue  by  the  com. 
pression  to  Avhich  it  is  sul)jected.  Were  the  cocain  conveyed  to  the 
apex,  as  when  it  is  instillated,  pain  would  not  so  soon  return. 

Should  the  paralyzation  of  the  pulp  fibers  in  the  canals  be  not  com- 
plete, instillation  may  then  be  pursued  as  previously  described. 

When  the  ])ulp  is  too  highly  sensitive  to  permit  complete  exposure  to 
the  cavity,  a  drop  of  adrenalin  and  a  one-fifth-grain  tablet  of  cocain  are 
inserted,  then  make  light  and  even  pressure,  gradually  increased  until  the 
pain  ceases.  The  pulp  may  then  be  completely  exposed,  and  the  usual 
solution  may  be  a])plied  with  sufficient  force,  as  described  above,  to  effect 
complete  anesthesia  of  the  pulp. 

Obtundation  by  Cataplioresis. — The  pulp  may  be  readily  anesthetized 
by  cocain,  as  described  for  the  treatment  of  hypersensitivity  of  the 
dentine  by  cataphoresis,  and  is  in  some  cases,  and  for  highly  nervous 
persons,  more  acce})talily  than  by  the  previously  stated  methods.  The 
requirements  are  that  insulation  be  i)crfectly  secured  ;  that  the  voltage 
be  low  at  the  commencement  and  be  gradually  increased  as  the  pain  limit 
permits.  When  the  pulp  can.be  uncovered  and  fully  exposed,  the  process 
may  be  continued  or  completed  by  the  pressure  method  or  by  instillation, 
as  may  be  most  applicable. 

When  the  pulp  is  removed  after  complete  anesthesia  by  either  of  the 
methods  above  considered,  the  root  canals  may  be  immediately  filled 
by  any  substance  which  may  be  conveyed  to  the  ajxw  and  perfectly 
occlude  the  canals.  It  sometimes  occurs  that  some  bleeding  takes  place 
at  the  end  of  the  severed  vessels.  This  may  be  stopped  by  an  applica- 
tion of  adrenalin. 

The  methods  above  defined  have  the  advantage  over  the  previous 
general  practice  of  devitalizing  with  arsenous  acid,  as  being  more 
promptly  effected,  with  much  less  pain  in  congested  cases,  and  with  the 
added  advantage  of  avoiding  any  danger  of  causing  discoloration  of  the 
teeth. 

There  is  also  the  further  important  consideration,  that  after-disturbance 
of  the  apical  region,  frequently  following  the  use  of  arsenic,  is  avoided. 


DEVITALIZATION  OF  THE  PULP.  407 

Devitalization  of  the  Pulp. 

There  arise  conditions  which  require  devitalization  of  the  pulp.  For 
this  purpose  no  agent  has  been  found  so  acceptable  as  arsenous  acid. 
The  formula  for  use  may  be  as  follows : 

R  Acid,  arsenosi      .    .  .  gr.  xx  R  Arf-enosi gr. 

Morphica  acetatis  .  .  gr.  xxx  Cocaina?  hydrochl.    .    .    .  aa 

01.  caryophylli   .    .  .  q.  s.  Eugenol q.  s. 

M.  et  ft.  pasti.  M.  et  ft.  pasti. 

When  arsenic  is  applied  to  a  living;  pulp  which  has  not  been  in 
a  state  of  disturbance,  and  therefore  is  in  the  condition  of  quies- 
cence considered  in  the  section  on  conservative  treatment  of  the  pulp, 
little  or  no  excitement  of  the  organ  takes  place.  If  the  paste  be 
carefully  applied  in  such  a  manner  as  to  avoid  pressure  the  pulp  does 
not  usually  become  excited  and  promptly  succumbs  to  the  chemical  force 
of  the  arsenic.  When  on  the  contrary  the  pulp  is  in  a  condition  of 
active  congestion,  such  as  is  presented  by  cases  of  prolonged  exposure, 
and  where  congestion  has  supervened  as  the  consequence  of  futile 
attempts  at  conservation,  violent  further  excitement  of  the  pulp  is 
nearly  certain.  In  this  condition  the  pulp  resists  the  absorption  of  the 
arsenic  and  repeated  applications  are  likely  to  produce  no  better  results. 
The  failure  to  discriminate  between  the  different  conditions  of  the  pulp 
accounts  largely  for  the  variation  in  the  action  of  the  same  formula 
upon  the  exposed  pulp. 

It  becomes  important,  therefore,  to  reduce  the  state  of  hyperesthesia 
of  the  pulp  and  to  relieve  the  congestion  in  many  instances  before 
commencing  the  devitalization. 

The  relief  of  congestion  requires,  first,  the  disinfection  of  the  surface 
of  the  pulp  and  of  the  dentin  contiguous  to  it.  The  most  efficient 
agent  for  this  purpose,  generally,  is  formalin,  which  after  the  first  slight 
pain  produced  by  it  is  almost  immediately  soothing.  Formalin  owes 
its  value  as  a  disinfectant  to  its  extreme  diffiisibilityand  in  the  strength 
applicable  does  not  appear  to  be  coagulative  in  its  action.  The  strength 
should  for  this  purpose  not  be  greater  than  2|  per  cent.  As  formalin  is 
composed  of  40  volumes  of  formaldehyd  with  60  of  water,  the  above- 
stated  percentage  of  formaldehyd  is  produced  by  adding  1  volume  of 
formalin  to  14  volumes  of  water. 

For  the  relief  of  ordinary  congestion  of  the  pulp  cocain  offers  the 
best  means,  since  it  has  direct  and  positive  action  over  the  capillaries, 
which  has  generally  been  adduced  to  account  in  part  for  its  anesthetic 
influence,  as  by  lessening  the  supply  of  blood  in  the  capillaries  it  there- 
by reduces  the  stimulation  of  the  nerve  fibrils.  In  cases  of  known  con- 
gestion as  determined  by  the  symptomatology  when  there  is  no  effiision 


408  COSiiERVATrVE  TRKATMEST  OF  THE  PULP. 

of  Ivinpli  or  pus  from  tlic  exposod  surface,  the  pulp  is  hatlud  with  a 
strong  solution  of  oocain  and  is  then  i-ovcred  with  a  deep  eap  lilled  with 
a  paste  of  cocain  and  oil  of  cloves  hcrnietically  scaled  in  for  several 
days,  when  usually  the  arsenical  i)aste  may  he  used  with  much-lessened 
danger  of  irritation.  An  excellent  method  where  delay  is  allowable  is  to 
cover  the  ptilj)  with  a  metal  cap  tilled  with  a  thin  paste  of  eugenol  and 
cocain  covered  hv  a  very  stitf  mixture  of  zinc  oxide  and  eugenol.  This 
filling  when  wetted  becomes  sufficiently  dense  to  remain  for  some  weeks. 

In  these  cases,  and  indeed  in  all  cases,  an  excellent  formula  for  de- 
vitalization will  be  founil  in  the  combination  of  10  grains  of  ar.senous 
acid  ground  well  with  20  grains  of  cocain.  A  very  minute  portion  of 
this  is  taken  upon  a  small  pledget  of  cotton  previously  charged  with  oil 
of  cloves  or  carbolic  aei<l,  which  is  laid  upon  the  exposed  point  and  then 
sealed  in  hermetically,  care  being  taken  to  avoid  compression  by  arching 
over  the  dressing  a  suitable  cap,  or  by  flowing  over  the  dressing  a  soft 
paste  of  one  of  the  mineral  cements.  Too  much  care  cannot  be  taken 
concerning  the  protection  of  the  gum  from  escaj)e  of  the  arsenical  ])repa- 
ration,  since  serious  destruction  of  the  gum  and  alveolus  may  be  produced 
by  the  exuding  of  the  arsenic. 

When  there  is  evidence  of  the  exudation  of  pus,  this  is  checked  by 
the  application  of  deliquescent  zinc  chloric!  or  by  washing  with  pyrozone. 
Usually  in  such  cases  the  surface  of  the  pulp  has  become  necrotic  by 
the  suppurative  process  and  will  not  be  so  repellant  of  the  arsenic  as  in 
ordinary  cases. 

The  time  usually  required  for  the  action  of  the  arsenic  to  reach  well 
toward  the  apex  of  the  roots  is  from  four  to  six  days.  This,  however, 
depends  upon  the  quantity  of  the  preparation  apjilied  and  the  resistance 
of  the  pulp  tissue.  As  the  aim  should  be  to  procure  the  nearly  com- 
plete death  of  the  pulp  by  one  application,  the  longer  period  is  preferable 
as  entailing  less  difficulty  and  the  expenditure  of  less  time  than  when 
shorter  intervals  are  allowed. 

The  Safety  Pocket. 

Instead  of  applying  the  arsenical  pellet  to  the  pulp,  it  is  preferable  in 
congested  cases  to  insert  it  in  an  opening  drilled  nearly  to  the  pulp  at  the 
cervical  region  of  the  cavity.  This  method  is  based  on  the  principle 
that  the  chief  seat  of  disturbance  of  the  ])ulp  is  about  the  region  of  ex- 
posure. Therefore  the  more  remote  the  application  be  made  from  the 
region  of  the  exposure,  the  less  the  liability  of  arsenical  irritation  and 
the  more  prompt  the  action.^ 

'  This  depression  was  called  a  safety  pocket  by  Clowes,  who  appeai-s  to  have  been  its 
originator. 


PRECAUTIONS  TO  PREVENT  DENTINAL   DISCOLORATION.    409 

A  not  uncommon  degree  of  soreness  of  the  pericementum  occurs  after 
arsenical  devitalization.  This  rarely  follows  the  use  of  cocain  as  above 
described,  which  leads  to  the  conclusion  that  some  of  the  arsenic  has 
entered  into  the  circulation  of  the  region.  Hence  it  is  advisable  when 
practicable  t)  follow  one  application  with  cocain  when  necessary  to  com- 
plete the  treatment. 

When  the  application  is  made  to  an  entirely  quiescent  pulp  it  will 
often  be  found  that  at  the  end  of  one  or  two  days  a  broach  may  be 
passed  to  the  end  of  single-rooted  teeth,  when  the  pulp  may  sometimes 
be  removed.  In  these  cases,  if  the  pulp  be  not  then  extracted,  it  will 
be  found  in  some  instances  that  at  a  subsequent  period  the  organ  has 
apparently  recovered  its  sensitivity.  The  explanation  of  this  is  that  the 
arsenic  apparently  paralyzes  the  nerves  of  the  pulp  without  having  acted 
deeper  than  the  surface.  In  this  case  the  application  should  be  repeated 
for  a  lengthened  period  without  disturbing  the  tissue.  On  removing 
the  dressings  if  the  broach  cannot  be  passed  to  the  end  of  the  canal 
either  of  two  courses  may  be  pursued ;  the  application  may  be  repeated 
without  removing  the  devitalized  portion,  or  a  strong  solution  of  cocain 
may  be  carefully  instillated  until  it  is  conveyed  to  the  apex  of  the  canal 
by  means  of  a  broach.  This  procedure  is  best  effected  by  isolating  the 
tooth  with  rubber  dam  and  then  filling  the  pulp  chamber  with  the  solu- 
tion of  cocain,  which  may  be  conveniently  conveyed  forward  by  gentle 
advancements  and  withdrawals  of  this  instrument.  The  best  form  of 
instrument  for  this  purpose  is  the  Swiss  broach  tempered  a  little  beyond 
a  spring  temper. 

A  matter  of  considerable  importance  in  connection  with  the  instru- 
ments used  in  these  manipulations  is  that  they  be  either  such  as  have 
not  been  previously  used  or  that  they  be  thoroughly  disinfected  previous 
to  use.  If  an  instrument  of  this  kind  is  indiscriminately  used,  having 
probably  been  infected  by  some  purulent  case,  septic  disturbance  of  the 
tissues  at  the  apex  is  brought  about.  The  safest  course  is  to  use  a  new 
broach  suited  in  size  and  stiffness  to  the  case  in  hand. 


Precautions  required  to  Prevent  Discoloration  of  the 

Dentin. 

It  sometimes  occurs  where  arsenous  acid  produces  much  irritation 
of  the  pulp  that  the  violent  congestion  occasions  disorganization  of  the 
blood  corpuscles,  resulting  in  the  distribution  of  the  hematin  throughout 
the  dentin.  This  most  unfortunate  result  is  liable  to  follow  the  applica- 
tion to  an  already  congested  pulp  when  the  application  is  made  without 
first  subduing  this  condition.  It  is  also  more  liable  to  happen  when 
under  these  circumstances  the  pulp  has  not  been  completely  denuded  of 
the  carious  matter. 


410  COySEEVATIVE  TREATMEST  OF  THE  PULP. 

The  removal  of  the  ultimate  layers  of  c-arious  matter  is  important  to 
permit  the  pulp  to  hktil  ami  thus  lo  iK-pk-te^the  engorge<l  ve.-sels.  It 
is  also  neoessan-  to  avoid  nuikiug  an  arsenical  application  until  the 
assurance  is  reached  that  the  bleeding:  has  completely  ceased,  else  subse- 
quent bleeilinjr  may  induce  discohtration.  In  addition  the  bh'cding  or 
any  other  kind  of  effusion  prevents  direct  contact  between  the  pulp  and 
the  arsenical  paste. 

These  greneral  directions  apply  also  to  the  eniplovmeut  of  jx>\v- 
dered  cobalt  as  a  devitalizer.  The  difference  betAveen  the  action  of 
Ciibalt  and  arsenous  acid  is  due  to  the  variations  in  their  respective 
solubility  in  the  fluids  of  the  pulji — cobalt  having  a  low  rate  of  stdu- 
bility.  For  this  reason  this  substance  requires  a  longer  interval,  at 
least  a  week  being  necessary  for  its  action  to  extend  into  the  canals.  In 
anterior  teeth  a  shorter  peri<xl  should  l>e  chosen.  With  this  substance 
it  is  of  extreme  importance  that  the  application  be  made  directly  to  the 
pulp.     The  method  is  as  follows  : 

A  pellet  of  cotton  the  size  of  a  piuhead  is  saturated  with  any  of  the 
essential  oils  ;  it  is  then  dipped  iu  the  powder  and  laid  upon  the  pulp. 
The  previously  stated  precautions  are  taken  to  prevent  pressure  of  the 
pellet  of  cotton  upon  the  pulp  and  to  protect  the  cavity  from  the  ingress 
of  moisture. 

In  these  procedures  connected  with  the  removal  of  the  pulp  the  use 
of  alcohol  is  an  im]x>rtant  aid.  since  on  account  of  its  affinity  for  water 
it  much  aids,  in  addition  to  its  cleansing  properties,  in  the  procurement 
of  dryness  of  the  parts.  Desiccation  of  the  pulp  chamber  materially 
assists  in  all  the  delicate  procedures  connected  with  the  treatment  of 
this  class  of  cases.  It  lessens  the  pain  of  the  remaining  living  ]X)rtion 
of  the  pulp,  and  by  giving  tirmness  to  the  devitalized  part  makes  more 
easy  the  removal  of  the  dead  tissue.  It  also  facilitates  the  action  of  the 
disinfectants  which  may  be  employed  to  prevent  rapid  changes  in  the 
organic  contents  of  the  canal.  The  process  of  desiccation  may  be  much 
facilitated  by  the  concurrent  injection  of  warmed  air. 

It  should  be  emphasized  that  in  all  procedures  connected  with 
the  treatment  of  pulps  undergoing  devitalization  the  teeth  should  be 
isolated  by  the  use  of  rubber  dam.  This  is  necessary  not  only  to 
facilitate  observation  and  secure  dryness  but  to  protect  from  mouth 
infection. 

The  removal  of  the  dead  pulp  tissue  is  effected  by  small  barbed 
broaches  which  are  passed  between  the  pulj)  and  the  walls  of  the  canal. 
When  these  reach  the  apex  the  pulp  may  in  most  instances  be  wound 
U|K)n  the  instruments  by  a  gentle  rotation.  When  this  does  not  take 
place  because  of  the  loss  of  consistence  of  the  tissue,  it  is  broken  up  by 
constant  rotation  of  the  instrument  and  removed  piecemeal.     The  dis- 


PRECAUTIONS   TO  PREVENT  DENTINAL  DISCOLORATION.     411 

placement  of  the  shreds  is  best  effected  by  wrapping  the  broach  with  a 
few  fibers  of  cotton  dipped,  in  alcoliol. 

Previously  t«  this,  free  communication  must  be  established  between 
the  cavity  and  the  pulp  chamber,  as  well  as  such  a  formation  of  the 
lines  of  approach  to  the  canals  of  the  root  as  will  give  free  access,  not 
only  for  the  removal  of  the  dead  tissue,  but  as  well  to  facilitate  the 
complete  closure  of  the  root  canals  to  the  apices  to  prevent  the  ingress 
of  organic  matter  from  the  adjacent  tissues. 

Minute  directions  for  the  form  of  approach  to  the  various  canals  and 
the  related  procedures  will  be  found  in  the  next  chapter. 


CHAPTER   XVII. 

THE  TBEATMENT  AND  FILLING  OF  BOOT  CANALS. 

By  Henry  H.  Burchard,  M.  D.,  D.D.S. 


Pathological  Conditions. 

The  modes  of  treatment  of  the  pulp  chambers  and  canals  of  teeth 
containing  non-vital  pulps,  or  those  in  which  the  pulp  is  absent,  are 
determined  and  governed  by  the  pathological  conditions  present.  These 
conditions  may  be  broadly  divided  into  aseptic  and  septic ;  /.  e.  those 
which  have  not  been  invaded  by  micro-organisms,  the  others  those  in 
which  the  pulp  or  its  remnants  furnish  the  soil  in  which  the  develop- 
ment of  micro-organisms  has  taken  place. 

The  first  class  includes  those  cases  in  which  the  pulp  has  been  inten- 
tionally devitalized  en  masse,  and  also  those  in  which  the  organ  has 
undergone  a  process  known  as  mummification,  or  dry  gangrene.  This 
latter  condition  is  occasionally  found  as  a  consequence  of  traumatic 
death  of  the  pulp  without  exposure,  and  sometimes  as  a  sequel  of 
attempts  at  conservation  of  exposed  pulps  by  capping  them  with  zinc 
oxychlorid. 

The  septic  cases  may  be  divided  into  classes  according  to  the  depth 
of  invasion  of  septic  organisms  ;  they  range  from  superficial  ulceration 
of  the  pulp,  to  its  disorganization  through  putrefaction,  and  the  infection 
of  the  tissues  beyond  the  apex  of  the  root. 

Immediately  upon  or  even  before  exposure  of  the  dental  pulp, 
its  surface,  and  subsequently  its  substance,  is  invaded  by  several 
of  the  many  forms  of  organisms  which  find  a  habitat  in  the  human 
mouth. 

The  first  of  the  septic  cases  are  those  in  which  organisms  have 
invaded  the  coronal  portion  of  the  pulp  and  destroyed  part  of  its  sub- 
stance— through  a  process  of  ulceration.  Such  cases  become  aseptic 
through  the  removal  of  the  pulp  en  masse,  provided  no  organisms  be 
carried  into  the  canal  during  or  subsequent  to  the  removal  of  the 
pulp. 

The  second  class  of  cases  comprises  those  in  which  septic  organisms 
have  invaded  the  pulp  along  the  direction  of  its  veins  and  destroyed 
the  mass  of  the  organ  through  a  process  of  suppuration.     In  these  cases 

413 


414 


THE   TRKATMKyT  AND  FTLLIXO    OF  ROOT  VASALS. 


it  i.>;  not  uiKXJininon  to  tiiul  the  tissues  ot"  the  apieal  region  att'eeted  in 
some  degree  prosumahly  by  infection  witli  the  waste  products  of  the 
org-anisnis,  a  transitory  pericementitis  occurring  which  ceases  when  tlie 
dead  pulp  skiughs  from  its  vital  connection  at  the  apex.  The  succeed- 
ing stages  of  the  infection  are  those  of  moist  gangrene  and  putrefactive 
decomposition  of  the  pulp  tissues,  and  later  of  the  contents  of  the 
tubules.  Following  upon  these  conditions  are  affections  of  the  cemen- 
tum  and  the  pericementum  in  the  apical  region,  resulting  in  an  iuHam- 
niatory  process  in  these  parts. 

All  of  these  stages  of  infection  and  decomposition  may  be  foinid  in 
the  piill>  at  one  time,  the  suppurative  proce.-s  })reeeding  that  of  putre- 
faction.    Cultures  made  from  a  gangrenous  pulp  (see  Fig.  385)'  showed 


Fig.  385. 


--> 


Micro-orgauisms  found  in  cultures  from  a  gangrenous  pulp. 

the  smaller  cocci  and  diplococci  (5)  nearest  the  apex  of  the  root  (c,  Fig. 

385,  1)  where  suppuration  was  in  progress;  the  larger  forms  and  more 

varieties  were  found  in  the  necrosed  and  decomposing  portions  of  the 

'  Miller,  Dental  Cosmos,  July,  1894. 


PATtlOLOGICAL   CONDITIONS.  415 

pulp  (4,  3,  2),     The  cases  of  gangrenous  pulps  exhibit  a  mixed  infec- 
tion, several  varieties  of  cocci,  bacilli,  and  spirochsetes  being  found.^ 

Cases  are  occasionally  seen  in  which  the  pulp  of  a  non-carious  tooth 
has  been  devitalized  in  consequence  of  a  blow,  injuring  the  vessels  as 
they  enter  the  apex  of  the  root ;  the  same  effect  is  not  rare  as  a  conse- 
quence of  too  rapid  or  extensive  movement  of  teeth  in  regulating.  The 
pulps  in  such  cases  are  probably  destroyed  by  thrombosis  of  the  vessels 
at  the  root  apex.  The  death  of  the  pulp  may  not  be  detected  for  years  ; 
when  evidences  of  albuminous  decomposition  are  discovered,  a  growing 
opacity  and  changing  color  of  the  tooth  may  be  detected.  In  other 
cases  alveolar  abscesses  may  form  and  discharge  at  some  point  near  the 
tooth,  or  it  may  be  at  some  distance  from  it.  It  is  presumed  that  the 
organisms  which  have  effected  this  decomposition  of  the  pulp  resulting 
in  the  suppurative  process  have  found  their  way  to  it  via  the  blood 
current. 

It  is  within  the  experience  of  every  dentist  that  the  products  of 
decomposition  occurring  under  these  conditions  afford  a  suitable  soil  for 
the  development  of  virulent  micro-organisms  as  soon  as  the  tooth  is 
opened  to  the  air. 

The  several  conditions  described  are  to  be  regarded,  for  purposes  of 
treatment,  as  definite  pathological  states.  The  treatment  is  to  be 
directed  to  the  attaining  of  such  conditions  as  shall  insure  the  retention 
of  the  tooth  with  an  entire  absence  of  pathological  manifestations. 
Rational  therapeutics  should  govern  each  procedure. 

Cases  in  which  the  Pulp  has  been  Intentionally  Destroyed  and  Re- 
moved en  masse. — As  this  procedure  usually  has  been  determined  upon 
in  consequence  of  suppuration  or  inflammation  of  the  pulp,  the  septic 
organisms,  the  staphylococci,  streptococci,  and  bacilli,  have  followed 
the  course  of  the  inflammation,  i.  e.  along  the  veins.  The  organisms  of 
putrefaction,  if  present,  have  affected  but  in  very  limited  degree  the 
most  external  portions  of  the  pulp,  so  that  the  color  of  the  dentin  is 
unaltered  except  to  a  very  slight  depth.  After  the  removal  of  the  pulp 
the  contents  of  the  tubules  are  chemically  unchanged,  and  the  canals 
contain  no  organic  matter,  except  the  blood  which  may  have  escaped  in 
consequence  of  tearing  away  the  pulp.  There  may  also  remain  odonto- 
blasts which  have  become  mechanically  detached  during  the  operation. 
Provided  no  organisms  have  been  introduced  during  or  subsequent  to 
the  operation  of  extirpation,  the  canals  are  aseptic.  If  proper  anti- 
septic precautions  have  been  taken,  sterilizing  and  isolating  the  tooth  to 
be  operated  on  and  also  the  instruments  employed,  no  infection  occurs. 
These  are  the  cases  in  which  immediate  root  filling  is  to  be  recommended 
and  may  be  practised  with  success. 

'  See  Fig.  397. 


41(3 


THE   TREATMEST  A.\l>   FILLISU    Ol'  ROOT  (ASARS. 


Fifi.  38(). 
Pigment.    S  +  hemoglobin. 


If   the   septic   process   has    invaded   tlic    |>ul|)   extensively  the   pulp 

tissue,  as  its  destruction  proo;res.ses,  be- 
comes the  seat  and  soil  of  ])utrefactive 
decomposition  involving  al.'^o  to  a  vari- 
able extent  the  contents  of  the  dentinal 
tubules,  and  the  color  of  the  dentin  lui- 
dergoes  a  series  of  changes."  The  a})- 
pended  figure  (Fig.  o8G)  gives  a  graphic 
diagrammatic  representation  of  the  serial 
decomposition  of  an  infected  pulp.  The 
albuminous  constituents  of  the  ])ulp  un- 
dergo fatty  transformation  ;  next  putre- 
factive decomposition  attended  by  the 
evolution  of  hydrogen  sulfid,  anmionia, 
and  other  end  products.  According  to  the 
extent  of  invasion  and  its  variety,  waste 
fatty  prod-  products  arc  formeil  (ptomains  and  al- 
ucts.  j.^^i  substances)  by  the  organisms  which 

act  as  irritants  to  the  vital  tissues,  until, 
when  the  apical  but  still  vital  portions 
of  the  pulp  become  the  soil  for  the  de- 
velopment of  pyogenic  organisms,  the 
tissues  of  the  apical  region  are  aifected. 
Usually  in  the  later  stages  of  pulp  sup- 
puration the  tooth  becomes  sensitive  upon  percussion.  Succeeding  this 
state  of  affairs  is  a  period  of  delusive  quiet,  during  which  the  ai)ical 
tissues,  although  doul^tless  affected  by  the  toxic  sub.stances  present, 
exhibit  but  slight  subjective  symptoms.  The  remnants  of  the  pulp  are 
undergoing  progressive  decomposition,  as  are  also  the  contents  of  the 
dentinal  tubules.  After  a  variable  period,  governed  by  the  virulence 
of  the  organisms  present  and  the  inherent  resistance  of  the  vital  tissues 
of  the  apical  region,  these  latter  succumb,  poisoned  by  the  toxic  sub- 
stances formed  in  contact  with  them,  and  an  inflammatory  action  arises  ; 
this  may  be  subacute,  evidenced  by  sensitiveness  upon  percussion  and  a 
deepening  of  the  gum  color  overlying  the  apex  of  the  root,  constituting 
a  condition  known  as  subacute  pericementitis  ;  or,  if  the  attack  be  more 
severe,  or  the  resistance  lessened,  the  symptoms  are  more  violent ;  there 
is  a  pronounced  hyperemia,  quickly  succeeded  by  the  evidences  of 
marked  inflammatory  action.  The  tooth,  owing  to  the  effusions  in  the 
pericementum,  becomes  elevated  and  exquisitely  sensitive  to  touch ; 
the  color  of  the  gum  deepens,  and  heavy  tlirobbing  pain  is  complained 
of;  acute  pericementitis  is  in  progress.  In  more  severe  cases  marked 
*  See  Chapter  XX.  on  Bleaching. 


COj.NHs; 
IIoO  and  HoS 


Aromatic    and 


Ptomains. 


Peptones, 
Pus. 


THERAPEUTIC  AGENTS.  417 

oedema  of  the  gum  and  it  may  be  of  the  face  arises ;  the  pulse  increases 
in  volume,  tension  and  frequency ;  febrile  action,  with  a  temperature  as 
high  as  103°  or  104°  may  occur;  in  other  cases  distinct  evidences  of 
septic  intoxication  may  appear,  and  indeed  even  septicemia  or  pyemia  ^ 
may  result  at  a  later  stage. 

The  severity  of  the  inflammatory  action  is  no  doubt  governed  in  part 
by  the  variety  of  the  infecting  organisms,  and  again  by  the  physical 
condition  of  the  individual  attacked.  Judging  from  the  mode  of  prog- 
ress and  attack,  the  staphylococci  are  the  offenders  where  the  inflam- 
matory action  is  circumscribed,  and  the  streptococci  in  cases  which 
exhibit  a  tendency  to  spread  along  the  course  of  the  fascia  and  produce 
phlegmonous  inflammation.^  Schreier^  has  found  the  almost  invariable 
presence  of  a  diplococcus  in  this  condition,  probably  the  diplococcus 
pneumonice. 

Individuals  presenting  any  of  the  several  manifestations  of  struma, 
inherited  or  acquired,  suffer  from  a  debility  of  general  vital  processes, 
and  may  have  the  inflammatory  action  run  a  riotous  course  (see 
Alveolar  Abscess,  Chapter  XVIII,).  As  a  rule,  when  a  tooth  has  been 
the  seat  of  subacute  pericementitis  for  a  lengthened  period,  or  of  acute 
septic  pericementitis  for  from  twenty-four  to  forty-eight  hours,  there  is 
more  or  less  death  of  cellular  elements  in  the  inflammatory  effusion, 
pus  forms,  and  alveolar  abscess  is  established  (see  Chapter  XVIII.). 

In  cases  of  subacute  pericementitis,  even  those  in  which  pus  forma- 
tion is  not  evident,  the  tissues  of  the  apical  region  are  assailed  by  the 
products  of  putrefactive  decomposition,  which  latter  process  may  prove 
difficult  to  overcome,  the  tissues  rebelling  at  each  attempt  to  close  the 
outlet  to  the  escape  of  gases  which  irritate  them. 

Each  phenomenon  mentioned  as  accompanying  the  stages  of  septic 
infection  and  albuminous  decomposition  forms  an  item  for  consideration 
in  the  therapeutic  measures  to  be  applied. 

Therapeutic  Agents. 

The  natural  and  true  inference  from  what  has  been  stated  is  that  the 
class  of  therapeutic  agents  to  be  locally  employed  in  any  of  these  condi- 
tions are  all  included  under  the  general  order  of  germicides,  antiseptics, 
and  disinfectants. 

The  one  distinguishing  feature  that  all  of  these  substances  have  in 
common  is  the  power — differing  in  degree  in  each — of  destroying  patho- 
genic organisms  or  rendering  innocuous  their  waste  products ;  their 
other  properties  differ  widely,  so  that  the  agent  for  application  to  spe- 

^  See  case  of  Dr.  E.  T.  Darby,  Proc.  Odontological  Society  of  Pennsylvania,  1892. 
^  See  case  reported  by  Dr.  E.  C.  Kirk,  Proc.  Odontological  Society  of  Pennsylvania, 
1892.  3  gge  2)ental  Cosmos,  vol.  xxxv.,  1893,  p.  617. 

27 


418  THE  TREATMEyT  AM)   Ffl.IJXa    OF  ROOT  CANALS. 

cific  disease  conditions  is  selected  with  a  rcjianl  to  which  shall  best  and 
most  completely  attain  a  definite  end.  According  to  the  effects  produced 
upon  albumin  the  agents  under  consideration  may  be  placed  in  two 
classes,  coagulants  and  non-coagulants.  In  the  former  class  are  in- 
cluded salts  of  the  metals  and  alcohols ;  in  the  latter,  many  of  the 
essential  oils. 

Mineral  acids  and  the  alkalies  act  by  chemically  destroying  the 
albumin.  The  metallic  salts  which  have  been  employed  or  tested  as 
germicides  in  pulp  canals  arc  the  clilorids  of  zinc  and  of  aluminum,  the 
bichlorid  of  mercury,  the  bichlorid  of  gold  and  sodium,  the  sidfate  of 
copper,  and  the  nitrate  of  silver.  The  salts  of  copper,  silver,  and  gold 
are  not  adapted  on  account  of  the  discolorations  produced  by  them. 
Mercuric  chlorid  is  open  to  the  same  objection  ;  thus  the  only  metallic 
salt  having  general  application  is  zinc  chlorid. 

The  alcohols  employed  are  the  ethylic  (commercial)  alcohol ;  j)henylic 
alcohol,  /.  e.  carbolic  acid,  and  creosote,  with  the  coal-tar  derivatives, 
tiie  cresols.  In  this  connection  formalin — a  40  per  cent,  solution  of  the 
gas  formaldehyd  in  water  should  be  mentioned  very  favorably ;  in 
dental  practice  it  is  reduced  to  a  strength  of  3  to  5  per  cent. 

Preparations  of  iodiu,  bromiu,  and  ehlorin  are  all  ])owerful  anti- 
septics and  disinfectants.  Bromiu  is  inapplicable  owing  to  its  irritat- 
ing effects  and  offensive  odor  ;  ehlorin  is  employed  in  the  form  of 
hypochlorites  ;  usually  in  the  solutions  called  electrozone  and  meditrina, 
electrolytic  products  of  sea-water.  Labarraque's  solution  of  sodium 
hypochlorite  appears  to  have  fallen  into  general  disuse,  as  have  also  the 
hyposulfites.  The  usual  form  in  which  iodiu  is  applied  is  as  the 
tincture.  lodin  trichlorid  is  said  *  to  be  five  times  as  strong  as  mercuric 
chlorid  as  an  antiseptic. 

The  essential  oils  recommended  as  antiseptics  for  employment  in 
canal  and  dentin  sterilization  are  those  of  thyme,  cinnamon,  cassia, 
myrtle,  and  eucalyptus. 

The  alkalies  employed  as  sterilizing  agents  are  Schreier's  alloy  of  po- 
tassium and  sodiiun,  called  Kalium-natrium  ;  sodium  carbonate  and  so- 
dium dioxid.  The  mineral  acids  which  have  been  recommended  are  hydro- 
chloric and  sulfuric,  the  latter  by  tiie  method  described  by  Dr.  Callahan.^ 

The  gases  oxygen  and  ehlorin,  in  statu  nascendi,  are  employed  as 
sterilizing  agents,  the  former  extensively.  When  these  are  applied  as 
bleaching  agents,  the  sterilization  is  coincidently  accomplished,  as 
pointed  out  in  the  chapter  on  Bleaching. 

Oxygen  is  liberated  from  aqueous  and  ethereal  solutions  of  hydrogen 

dioxid  and  solutions  of  sodium  dioxid. 

'  Langenbacli,  quoted  by  Miller,  Dental  Cosmos,  vol.  xxxiii.  p.  342. 
'•'  Proc.  Ohio  State  Dental  Society,  1894. 


THERAPEUTIC  AGENTS.  419 

lodol,  iodoform,  and  kindred  substances  are  not  employed  as  germi- 
cides per  se,  but  for  other  therapeutic  properties  possessed  by  them,  e.  g. 
their  supposed  capability  of  maintaining  sterilization  after  the  more 
powerful  antiseptics  have  been  employed  as  germicides. 

Aristol,  dithymol  biniodid,  is  another  member  of  this  group,  which 
owing  to  its  chemical  composition  is  theoretically  preferable  to  the 
others.  It  contains  twice  the  quantity  of  iodin  in  loose  combination, 
and  in  addition  has  as  its  base  a  powerful  antiseptic,  thymol. 

These  agents  are  supposed  to  act  as  antiseptics  in  consequence 
of  setting  free  iodin  when  brought  in  contact  with  albuminous 
substances. 

It  has  been  demonstrated  that  iodoform  is  not  a  germicide  (organ- 
isms growing  about  it),  but  it  appears  to  lessen  or  destroy  the  effects 
of  toxic  substances  generated  about  it  as  the  result  of  albuminous  de- 
composition. 

The  final  antiseptic  to  be  mentioned  is  the  mechanical  removal  of 
infected  tissues. 

Zinc  chlorid  forms,  when  brought  in  contact  with  albumin,  a  dense 
and  almost  colorless  coagulum  of  zinc  albuminate.  Placed  at  one  end 
of  a  capillary  tube  containing  albumin,  it  diffuses  rapidly  through  the 
solution,  coagulating  it  throughout.^ 

Carbolic  acid  forms  less  dense  coagula,  and  creosote  still  less. 
Mercuric  chlorid  and  silver  nitrate  form  complete  coagula  also.  It  may 
be  well  in  this  connection  to  call  attention  to  an  observation  made  by 
Dr.  Kirk,  in  an  essay  read  before  the  First  District  Dental  Society  of 
New  York,  that  coagulation  is  a  chemical  process,  as  illustrated  in  the 
union  of  mercuric  chlorid  with  albumin.  The  metallic  salt  does  not 
act  by  catalysis,  but  there  is  a  distinct  quantitative  relation  between  the 
coagulant  and  the  coagulable  material,  the  process  ceasing  when  the 
quantitative  relation  of  these  bodies  is  chemically  satisfied ;  if  an  excess  of 
HgClg  be  employed,  a  definite  amount  of  the  salt  combines  with  albumin 
to  form  an  albuminate  of  mercury  suspended  in  a  solution  of  the  chemical 
excess  of  HgClj.  If  an  excess  of  the  albumin  be  employed,  an  albumin- 
ate of  mercury  is  formed  suspended  in  a  solution  of  albumin.  The  albu- 
minate of  mercury  when  brought  in  contact  with  an  easily  decomposable 
sulfur  compound  may  be  reduced  by  the  formation  of  mercury  sulfid 
and  the  albumin  be  restored  to  its  primary  condition,^  which  would 
seem  to  indicate  that  HgCl2  is  an  unreliable  germicide  where  putrefac- 
tive decomposition  is  in  progress  giving  rise  to  II2S. 

Formalin  readily  and  quickly  affects  both  albumin  and  gelatin,  con- 
verting them  into  a  tough  coagulum  which    maintains   its   form   and 

^  Prof.  James  Truman,  Proe.  Academy  of  Stomatology  of  Philadelphia,  Dec.  1894. 
^Abbott,  Principles  of  Bacteriology,  3d  ed.,  1896. 


420  THE  TREATMEST  AM)  FFLLTXG   OF  ROOT  CAXALS. 

appears  to  bo  persisteutly  antiseptic  tor  I'crtain  varieties  of  uiiero- 
organisms. 

The  essential  oils  aet  as  antisepties  withont  eoafjnlation,  having 
markedly  less  germicidal  aetion  than  the  agents  above  mentioned. 
Placed  in  root  canals  they  diffuse  through  the  dentin,  maintaining  a 
prolonged  antiseptic  influence  ;  their  absorption  into  the  dentin  pro- 
dnces  some  degree  of  discoloration  in  that  tissue.  These  oils  differ  in 
antiseptic  power.  Oil  of  thyme  and  oil  of  cinnamon  stand  at  the  head 
of  the  list,  oil  of  cloves  and  eucalyptus  being  far  below  them  in  the 
antiseptic  scale.  The  antiseptic  value  of  oil  of  thyme  is  dependent  upon 
its  active  principle,  thymol,  which  is  separated  from  the  oil  by  fractional 
distillation  and  further  purification  by  treatment  witli  sochi  and  then  by 
hydrochloric  acid.  Thymol  has  high  therapeutic  value  not  only  in  con- 
nection with  pulp-canal  sterilization,  l)ut  of  the  infected  pulp  itself. 
Attention  was  first  directed  to  the  value  of  thymol  as  a  sterilizing  agent 
for  infected  pulps  by  Hartmann,'  and  his  observations  were  subsequently 
confirmed  by  experimental  tests  made  by  C.  Kose.^ 

Thymol  appears  to  possess  the  valuable  property  of  destroying  the 
infecting  organisms  without  at  the  same  time  injuring  the  vitality  of  the 
cellular  elements  of  the  pulp  tissue,  as  the  investigators  cited  have  re- 
ported numerous  cases  of  recuperation  of  badly  infected  pulps  under 
treatment  by  thymol  applied  in  substance. 

The  alkalies  employed  as  antiseptics  saponify  the  fatty  matters  formed 
in  the  course  of  albuminous  decomposition,  and  dissolve  albuminous  sub- 
stances with  which  they  are  brought  in  contact.  The  first  of  these, 
the  alloy  of  potassium  and  sodium,^  when  placed  in  contact  with  decom- 
posing pulp  tissue  abstracts  the  elements  of  water  from  it,  and  sodium 
and  potassium  hydroxids  are  formed,  which  have  the  power  of  saponi- 
fying fiits  and  dissolving  albumins.  Sodium  carbonate  has  similar 
properties,  but  acts  less  energetically.  Sodium  dioxid  under  the  same 
conditions  forms  sodium  hydroxid,  nascent  oxygen  being  set  free,  which 
acts  as  a  germicide  and  also  decomposes  the  coloring  substances  in  the 
dentinal  tubules,  acting  as  a  bleaching  agent  to  the  dentin.  Solutions 
of  hydrogen  dioxid  are  decomposed  into  water  and  nascent  oxygen  in 
contact  with  the  putrescent  canal  contents  ;  the  liberated  oxygen  acting 
as  an  oxidizer. 

The  mineral  acids  when  employed  subserve  a  double  office.  Sul- 
furic acid  placed  at  the  mouth  of  fine  canals  unites  with  and  decom- 
poses the  calcium  salts  of  the  dentin,  forming  calcium  sulfate,  easily 
removable  with  the  fine  canal  scrapers ;  its  second  office  is  that  of  an 

'  See  Devische  Monatsschrift  f.  Zahnheilkunde,  vols.  i.  and  iv.,  1892. 

*  See  Dental  Cosmos,  vol.  xxxvi.,  1894,  pp.  41  and  3fi2. 

'  Schreier's  preparation  (see  Dental  Common,  vol.  xxxv.,  1893,  p.  22). 


MATERIALS  FOR  FILLING   THE  ROOT  CANAL.  421 

effective  germicide,  destroying  all  organisms  with  %vhich  it  is  brought 
in  contact. 

Materials  for  Filling  the  Root  Canal. 

The  materials  employed  to  hermetically  seal  the  apical  foramina  of 
sterilized  canals  are  in  the  condition  of  solids  inserted  en  masse  or  in 
successive  portions ;  or  they  are  pastes  applied  alone,  or  upon  some 
medium  which  acts  as  a  vehicle.  Aiiother  class  are  ordinarily  solid,  but 
are  brought  to  a  condition  of  fluidity  before  inserting  them. 

The  properties  which  should  be  possessed  by  a  satisfactory  canal  filling 
are  as  follows  :  Impermeability — it  should  hermetically  seal  the  apical 
foramen,  effectually  preventing  the  egress  of  pathogenic  organisms  or 
their  waste  products  from  the  canals  to  the  tissues  of  the  apical  region 
and  vice  versa,  and  it  should  prevent  transudations  from  the  apical 
tissues  into  the  pulp  canals.  It  should  be  unchanged  by  the  influences 
about  it ;  be  unirritating  to  the  soft  tissues ;  and  possess  sufficient 
plasticity  to  permit  of  its  ready  adaptation  to  the  walls  of  the  space  it  is 
designed  to  fill.  It  should  be  at  least  aseptic  w'hen  applied,  and  pref- 
erably antiseptic  :  it  is  to  be  esteemed  in  the  degree  that  it  maintains 
this  latter  quality  in  combination  with  the  other  desiderata  stated. 

The  solid  materials  which  have  been  employed  for  this  purpose  are 
gold  foil,  shredded  tin,  gold,  copper  and  lead  points.;  carbon  points 
saturated  with  creosote,  wood  points  dipped  in  creosote  and  partially  car- 
bonized cotton  wool  have  been  used  for  this  purpose.  The  readily  oxi- 
dizable  metals  have  not  found  favor  owing  to  the  possibility  of  dentinal 
staining  following  their  employment.  The  plastic  materials  employed 
are  softened  gutta-percha  cones  and  the  zinc  oxychlorid  cement.  The 
latter  and  also  other  pastes  are  frequently  employed  to  fill  the  meshes 
of  a  wisp  of  crude  cotton  wool  or  asbestos  fiber,  these  latter  being  the 
vehicle  for  carrying  the  paste  into  position.  It  is  to  be  remembered 
that  when  cotton  fiber  is  kept  in  prolonged  contact  with  zinc  chlorid, 
the  cellulose  undergoes  a  chemical  change :  it  is  converted  into  a  pectous 
substance  called  amyloid,  which  is  a  colorless  colloid,  unchangeable  in 
the  conditions  existing  at  the  apex  of  a  pulp  canal. 

Cotton  itself  may  be  included  among  the  plastic  root  fillings. 

The  fluid  substances  employed  are  solutions  of  red  gutta-percha 
base  plate  in  chloroform,  constituting  the  so-called  chloro-percha,  which 
contains  in  this  case  vermilion  ;  if  made  of  white  gutta-percha  it  contains 
zinc  oxid  and  a  variable  amount  of  other  mineral  substances.  The 
other  members  of  this  class  are  salol  and  paraffin,  made  fluid  by  heat 
before  insertion  and  becoming  hard  when  cool. 

Gold  was  the  first  material  adopted  for  the  purpose  of  canal  filling, 
being  introduced  in  this  connection  by  Dr.  Maynard  over  fifty  years 


422  THE  TREATMENT  AM)   FILLISU    OF  ROOT  CABALS. 

ago.  Pro])orly  adaptod,  it  may  ho  made  to  lu'rmctioally  ^;eal  i\\o  ai)ical 
foramen.  It  i.s  difHfiilt  to  iiiaiiipuhito,  and  its  removal  alter  tJie  type  of 
adaptation  required  is  wellnigh  imj)ossible.  Tin  lias  the  same  virtues 
and  is  open  to  tlie  same  (^)bjeetion,  which  in  fact  obtains  when  any  metal 
is  forcibly  driven  into  the  apical  portion  of  the  canal.  It  is  hekl,  how- 
ever, and  with  a  measure  of  good  reason,  by  those  who  have  advocated 
the  employment  of  metal  for  this  ])nrpose,  that  when  a  pnl])  canal  has  ijcen 
thoroughly  sterilized  and  filled,  the  necessity  for  the  removal  of  the 
root  filling  will  never  arise.  The  degree  of  confidence  expressed  in 
this  opinion  has  not  yet  served  to  override  the  caution  of  conservative 
operators,  so  that  metals  have  an  extremely  limited  employment  in  ttiis 
connection. 

The  plastic  materials  most  frequently  recommended  and  whieli  sta- 
tistics and  general  experience  demonstrate  to  serve  most  acceptably  as 
canal  fillings,  are  the  oxychlorid  of  zinc  and  gutta-percha. 

The  zinc  cement  when  in  paste  form  may  be  readily  adapted  to  any 
accessible  canals,  and  it  maintains  during  and  for  some  time  after  set- 
ting an  antiseptic  action.  The  peculiar  and  specific  influence  exerted 
by  this  material  upon  the  albuminous  constituents  of  the  tooth  may  be 
seen  as  a  not  infrequent  sequel  to  its  employment  as  a  l)ulp  caj)})ing. 
Many  of  such  teeth  whose  pulp  chambers  have  been  opened  some  years 
after  the  capping  operation  are  found  to  have  had  their  pulps  changed 
to  a  dry  tough  mass  which  has  not  been  the  seat  of  septic  invasion  ; 
moreover,  the  normal  color  of  the  dentin  of  such  teeth  has  been  main- 
tained, showing  that  no  extensive  chemical  decomposition  has  occurred 
in  the  contents  of  the  tubules.  As  a  canal  filling  it  becomes  very  hard, 
remains  white.  Its  removal  when  indicated  may  be  accomplished  by 
repeated  applications  of  sulfuric  acid  after  the  Callahan  method  of  open- 
ing canals. 

When  freshly  mixed  the  oxychlorid  paste  is  markedly  irritating  to 
vital  tissue  with  which  it  is  brought  in  contact,  and  considerable  irrita- 
ti(m  to  the  apical  portions  of  the  peridental  membrane  not  infrequently 
follows  its  use  as  a  canal  filling.  This  irritation,  which  may  be  produc- 
tive of  much  pain,  is  due  to  the  diifusion  of  a  portion  of  the  zinc  chlorid 
through  the  apical  foramen  before  it  has  entered  into  chemical  combina- 
tion with  the  zinc  oxid  of  the  powder  used  in  forming  the  cement.  This 
irritative  action,  though  closely  similar  in  its  symptttmatology  to  the  early 
stages  of  septic  inflammation  of  the  apical  tissues,  does  not  terminate  in 
suppuration,  but  subsides  after  a  time  varying  from  a  few  hours  to  a  day 
or  two,  complete  resolution  taking  place  in  all  cases  where  the  canal  fill- 
ing has  been  judiciously  performed.  This  chemical  irritation  from  the 
uncombined  zinc  chlorid  may  be  avoided  by  first  placing  a  minute  pledget 


MATERIALS  FOR  FILLING    TEE  ROOT  CANAL.  423 

of  cotton  at  the  apex  of  the  canal,  saturated  witli  a  mild  antiseptic — ^-g-, 
creosote,  carbolic  acid,  or  an  essential  oil. 

When  the  meshes  of  cotton  are  filled  with  the  paste  made  thin,  the 
zinc  chlorid  acts  upon  the  cotton,  converting  it  into  amyloid ;  so  that 
if  a  pellet  of  cotton  moistened  with  a  sedative  antiseptic  be  placed  in 
the  apical  portion  of  a  root  canal  and  the  thin  paste  placed  over  it,  the 
filling  of  the  apex  after  the  chemical  action  noted  consists  of  the  un- 
changeable impervious  amyloid  and  not  of  cotton. 

Long  thin  gutta-percha  cones  are  readily  made  plastic,  but  the 
adaptation  of  the  material  to  the  walls  of  the  canal  is  less  intimate  than 
is  that  of  the  oxy chlorid  of  zinc.  It  is  unchangeable  in  the  conditions 
under  which  it  is  placed,  and  is  the  most  bland  and  unirritating  of 
filling  materials.  Its  removal  after  proper  placement  is  difficult  but  by 
no  means  impossible.  The  gutta-percha  compound  known  as  temporary 
stopping  has  similar  properties,  but  is  less  tough  in  texture. 

The  last  of  the  plastics  introduced  is  a  resinous  substance  called  the 
balsamo  del  deserto.  It  is  probably  an  exudation  from  one  of  the 
varieties  of  pine  or  fir.  Its  virtues  and  employment  were  first  described 
by  Dr.  W.  H.  White  of  Silver  City,  N.  M.  His  experiments  indicate^ 
that  the  resin  has  a  pronounced  antiseptic  action  ;  the  antiseptic  value  of 
the  material  is  enhanced  in  practice  by  the  addition  of  from  3  to  5  per 
cent,  of  oil  of  cassia,  which  combination  is  that  which  is  now  furnished 
by  the  supply  houses.  It  adheres  to  wet  surfaces,  and  is  perfectly 
non-irritating  to  soft  tissues  with  which  it  is  brought  in  contact.  It 
remains  unchanged  when  employed  as  a  canal  dressing.  Dr.  White 
finds  that  the  roots  of  temporary  teeth  which  have  been  filled  with  the 
material  suffer  no  interference  with  the  resorj)tion  process  because  of  its 
presence. 

Thin  solutions  of  gutta-percha  in  chloroform  (chloro-percha)  have 
wide  employment  as  fillings  for  fine  and  tortuous  root  canals.  These 
solutions  may  be  carried  into  any  canal  which  will  admit  the  finest 
broach.  They  shrink  in  hardening,  so  that  a  canal  filling  of  such  a 
solution  does  not  hermetically  seal  the  cavity  when  the  material  is 
hardened. 

The  solution  is  usually  employed  in  combination  with  the  gutta- 
percha cones.  Dr.  R.  Ottolengui  ^  recommends  a  method  which  may 
be  followed  with  advantage  :  A  number  of  pieces  of  floss  silk  about  an 
inch  long  are  saturated  with  chloro-percha  and  dried ;  these  are  then 
thrust  in  a  chloro-percha  canal  filling  while  it  is  fluid.  Should  it  ever 
become  necessary  to  remove  the  filling,  the  projecting  end  of  one  of  the 
pieces  of  silk  is  caught,  and  the  entire  filling  may  be  withdrawn. 

^  See  International  Dental  Journal,  vol.  xv.,  1894,  p.  690. 
^  Methods  of  Filling  Teeth. 


424  THE  TREATMENT  AXD   FILLING    OF  ROOT  CANALS. 

The  use  of  siilul  in  this  connection  was  first  dcscrihcd  and  advocated 
by  Dr.  A.  E.  Mascort  of  Paris.'  Salol,  the  salicylate  of  jihcnol,  is  mildly 
antiseptic.  When  brought  into  contact  with  alkalies  it  is  decomposed 
into  carbolic  and  salicylic  acids,  two  powerful  antiseptics.  It  melts  at 
40°C.  (104°F.),  and  if  fused  at  or  but  little  above  this  heat  it  crys- 
tallizes in  a  few  minutes  ;  if  the  heat  be  raised  to  a  higher  point  crystal- 
lization is  delayed  for  some  time  after  the  mass  has  cooled  far  below  its 
normal  melting-point.  The  melted  salol  may  be  readily  carried  into  any 
canal  which  will  admit  the  finest  broach.  Portions  of  the  material  which 
mav  be  carried  beyond  the  apical  foramen  apjiear  to  be  unirritating. 

Keports  as  to  the  })crmanence  and  value  of  this  material  vary  from 
enthusiastic  endorsement  to  imqualified  condemnation.  Many  of  those 
who  have  used  salol  have  found,  upon  reopening  canals  which  have 
been  filled  with  it,  an  absence  of  the  salol ;  however,  where  the  i)ractice 
has  been  to  employ  a  central  canal  filling  of  gutta-percha,  a  cone  of 
which  material  is  thrust  into  the  melted  salol,  in  such  cases  its  absence 
has  not  been  observed.  Salol  has  been  found  to  suffer  rapid  decomposi- 
tion in  canals  which  have  been  treated  with  one  of  the  fixed  alkalies 
just  before  the  salol  was  inserted. 

Paraffin  has  been  employed  for  a  canal  filling,  made  fluid  by  heat  and 
carried  into  the  canals  ;  it  is  bland,  unirritating,  unchangeable,  and  easily 
removable.^  It  mav  be  used  in  combination  with  salol  or  thymol,  both 
of  which  freely  dissolve  in  melted  paraffin,  conferring  upon  the  mass  an 
antiseptic  value,  or  it  may  be  mixed  with  aristol,  and  used  as  a  filling  in 
sterilized  canals.^ 

Before  discussing  the  cleansing  of  pulp  canals,  certain  means  and 
methods  suggested  for  avoiding  the  necessity  for  the  toil  and  care 
necessary  to  mechanically  cleanse  the  more  inaccessible  canals  require 
consideration.     These  agents  are  preservative  pastes. 

Mummification  of  the  Pulp. — As  early  as  the  introduction  of 
arsenous  oxid  as  a  devitalizing  agent  it  was  noted  that  a  certain  per- 
centage— or  rather,  an  uncertain  jiercentage — of  cases  gave  evidence  of 
little  or  no  disease  after  the  application  of  arsenic  and  its  sealing  in  a 
cavity  by  a  filling.  Later,  it  was  found  that  applications  of  pow^erful 
antiseptics  to  exposed  pulps  not  infrequently  %vere  followed  by  a  long- 
continued  quiet  of  that  organ  ;  still  later,  when  more  definite  knowledge 
was  possessed  of  the  pathological  results  which  might  follow  the  leaving 
of  portions  of  pulp  substance  in  the  canals  of  teeth  after  devitalization 
by  arsenic,  it  was  observed  that  after  saturating  the  canals  with  creosote 
or  zinc  chlorid  solutions,  many  cases  gave  little  or  no  evidence  of  peri- 
cemental disturbance  thereafter. 

1  Denial  Cosmo.-<,  1894,  p.  3-)2.  "  Ibid.  '  Ibid.,  June  1897. 


MUMMIFICATION  OF  THE  PULP.  425 

While  it  is  unquestionably  preferable  to  always  thoroughly  remove 
the  last  vestige  of  devitalized  pulps,  certain  cases  involving  inaccessible 
or  tortuous  canals  may  present  in  which  the  time,  care,  skill,  and  expense 
involved  in  perfect  cleansing  are  detriments  to  its  universal  practice. 
The  only  other  possible  solution  of  the  difficulty  is  to  so  alter  the  tissue 
not  removed  that  it  shall  remain  permanently  aseptic,  and,  if  possible 
to  make  it  so,  antiseptic. 

Observations  derived  from  clinical  experience,  although  undoubtedly 
of  great  and  permanent  value,  are  indeterminate,  and  our  truly  scientific 
knowledge  of  this  matter  dates  from  Dr.  W.  D.  Miller's  experiments.^ 
He  credits  Dr.  Witzel  with  the  first  systematic  observations  in  this 
direction.  Dr.  Witzel  in  1874,  "  devitalized  the  crown  portion  of  pulps 
by  means  of  arsenic,  extirpated  that  portion  leaving  the  pulp  in  the 
canals  undisturbed,  their  exposed  ends  being  treated  as  freshly  exposed 
pulps."  This  is  the  method  followed  by  Herbst,  who  employs  cobalt 
(which  is  native  arsenic  sulfid  or  metallic  arsenic)  instead  of  arsenic 
trioxid. 

Dr.  Miller's  experiments  have  shown  that  none  but  the  most  power- 
ful and  penetrating  antiseptics  have  value  as  permanent  sterilizers. 
These  are  :  The  cyanid,  bichlorid,  and  salicylate  of  mercury,  sulfate 
of  copper,  and  oil  of  cinnamon.  Orthocresol,  carbolic  acid,  trichlor- 
phenol,  and  zinc  chlorid  penetrate  the  pulp  tissue  rapidly,  but  are  too 
diifusible,  disappearing  in  a  few  weeks. 

He  classifies  salicylic  acid,  eugenol,  campho-phenique,  hydronaphthol, 
a-  and  ^-naphthol,  acetico-tartrate  of  aluminum,  and  some  essential  oils, 
resorcin,  thallin,  sulpho-carbolate  of  zinc,  etc.,  as  being  of  doubtful 
value. 

Those  nearly  or  quite  worthless  are  iodoform,  basic  anilin  coloring 
matters,  borax,  boric  acid,  dermatol,  europhen,  calcium  chlorid,  hydro- 
gen dioxid,  sozoiodol  salts,  tincture  of  iodin,  spirit  of  camphor,  and 
naphthalin. 

The  preparation  giving  the  best  results  consisted  of — Mercuric  chlo- 
rid, 0.0075  gram  ;  thymol,  0.0075  gram,  in  tablet  form. 

The  pulp  is  devitalized  ;  the  crown  portion  and  all  the  root  portion 
readily  accessible  is  removed ;  one  of  the  tablets  is  placed  in  the  pulp 
chamber,  crushed  by  means  of  an  amalgam  plugger,  and  covered  with 
gold  foil.  The  mercury  salt  tends  to  discolor  the  crown  of  the  tooth, 
so  that  its  employment  should  be  restricted  to  the  posterior  teeth ; 
indeed,  the  necessity  for  its  use  would  be,  as  a  rule,  found  with  these 
teeth,  being  those  from  which  it  is  most  difficult  to  extract  pulp  rem- 
nants.    Dr.  Miller  expresses  faith  in  the  power  of  oil  of  cinnamon  to 

^  Proc.  Columbian  Dental  Congress,  1893. 


42fi 


THE   TRKATyfKST  AND   FfLUXa    OF  ROOT  CANALS. 


IHTinancntly  storilizo  i)iil])  fragments.  lie  suggests  the  cNiuTiiucntal 
aijjilieation  of  the  sterilizing  tablets  to  such  teeth  as  are  readily  sal- 
vable  yet  Avhieh  are  for  various  reasons  ''consigned  to  the  forceps." 
Dr.  Theodore  Siklerberg  of  Sydney,  N.  S.  W.,  reports  excellent 
results  from  a  continuous  practice  of  this  variety  of  pulp  sterilization. 
He  employs  a  paste  composed  of — 


I|i.  Alum  exsic, 
Thymol, 

Glycerol, 
Zinc  oxid, 


q.s. 


to  make  stiff  paste. — M. 


Tt  will  he  noted  that  he  substitutes  dried  alum  for  the  tannin,  originally 
used  by  him  as  the  hardening  agent  :  his  experiments  .showed  the 
tannin  to  be  productive  of  discoloration.  Mercuric  chlorid  is  set  aside 
for  the  same  reason.  Oil  of  cassia  employed  in  tlu-  paste  also  caused 
discoloration.  At  present  Dr.  Soderberg  adds  a  small  quantity  of 
cocain  to  the  paste  to  prevent  the  pain  arising  from  the  action  of  the 
dried  alum.  He  states  (Nov.  1895)  that  he  has  in  a  year  applied  the 
})aste  in  97  cases  and  has  had  no  untoward  results.  The  method  of 
placing  the  material  is  shown  in  Figs.  387,  388. 


Fig.  387 


Fig.  388. 


a,  Caries  exposing  a  horn  of  the  pulp. 


a,  Root  portion  of  pulp ;  6,  mummifying  paste ; 
r,  zinc  phosphate ;  d,  gold  or  amalgam. 


C.  A.  Firth  of  Queenleyan,  N.  S.  W.,'  advises  the  omission  of 
zinc  oxid  from  the  paste,  to  avoid  the  formation  of  the  brown  tannate 
of  zinc.  He  suggests  the  use  of  a  mixture  of  tannic  acid  and  thymol 
equal  parts,  made  into  a  paste  with  glycerol  and  applied  with  ivory 
instruments,  to  avoid  diseolorations.  He  expresses  himself  as  gratified 
at  the  results  obtained.    Another  formula  suggested  by  the  same  gentle- 


Dental  Cosmos,  May,  189G. 


MUMMIFICATION   OF  THE  PULP.  427 


DESCRIPTION  OF  FIGS.  389,  390,  AND   391. 

Fig.  389.— Fig.  3  gives?  in  contrast  a  sectional  view  of  deciduous  and  permanent  upper  teeth 
divided  through  their  lateral  diameters. 

Fig.  4,  a  sectional  view  of  the  corresponding  lower  teeth  divided  through  their  antero-posterior 
diameters,  a,  b,  c  represent,  respectively,  the  deciduous  and  permanent  front  incisors  in  con- 
trast :  d,  e,f,  the  lateral  incisors  ;  g,  h,  i,  the  canines ;  k,  deciduous  molars,  upper  and  lower ;  and 
I,  m,  the  successors  to  the  deciduous  molars,  the  bicuspids ;  ?;,  o  represent  permanent  molars, 
c,/,  i,  m,  0  have  dotted  lines  indicating  the  thickness  of  enamel  removed  by  wear,  atrophy  of  the 
cementum,  and  reduction  in  the  size  of  the  pulp  due  to  progressive  calcification,  these  changes 
being  incident  to  old  age. 

Fig.  390  represents  in  Fig.  1,  letters  a  to  h  and  a  to^.  the  longitudinal  or  vertical  sections  of 
the  sixteen  upper  teeth,  showing  the  labio-palatal  diameter  of  the  pulp  chamber  and  canal  in 
crown  and  roots,  the  section  of  the  molars  being  through  the  anterior  buccal  and  palatal  roots, 
while  the  bicuspids  d  e  and  d_e  illustrate  the  result  of  such  a  compression  of  the  root  as  to 
divide  the  pulp  chamber  into  two  canals— a  condition  which  so  frequently  exists  in  these  flattened 
roots.  The  double-lettered  series,  d  d  to  h  h  and  dd  to  fiji,  represent  in  the  molars  a  section 
through  the  posterior  buccal  and  the  palatal  roots,  from  which  is  quite  readily  recognized  the 
slightly  greater  lateral  diameter  of  the  pulp  chamber  in  the  crown  and  the  larger  canal  in  the  poste- 
rior buccal  root  over  that  in  the  anterior  buccal  root,  while  the  bicuspids  lettered  eedd  and  ddee 
illustrate  a  modified  pulp  chamber  and  canal,  with  bifurcation  of  the  root  in  one,  these  being  cut 
through  a  different  axis  or  plane  from  the  single-lettered  series. 

Fig.  2,  letters  o  to  ft  and  a_  to  h_,  represent  the  sixteen  lower  teeth  with  the  section  through 
their  long  diameters,  as  in  the  upper  series.  These  incisors  illustrate  the  compressed  or  flat- 
tened condition  of  their  roots  in  contrast  with  the  cylindrical  character  of  the  roots  of  the  upper 
incisors,  while  the  bicuspids  d  e  and  d_e  illustrate  the  singleness  of  their  pulp  chamber  and  the 
cylindrical  condition  of  their  roots  as  in  contrast  with  the  flattened  or  compressed  condition  of 
the  roots  of  the  upper  bicuspids.  The  molars  /,  g,  k  and  f.  g.  h  represent  sections  through  the 
anterior  root,  illustrating  its  compressed  condition  and  divided  pulp  chamber  in  the  first  and 
second  molar,  and  a  somewhat  flattened  one  in  the  anterior  root  of  the  third  molar  ;  //,  g  g  ,hh 
and  //,  g  g,  h  h  represent  the  single  and  cylindrical  pulp  chamber  in  the  posterior  root  of  the 
lower  molars,  while  bb,  cc  and  aa.bb  represent  the  incisors  and  canines  of  the  same  series,  with 
modified  pulp  chambers  arising  from  modified  development. 

Fig.  391. — Fig.  l,from  a  to  ft  and_a  to _ft,  represents  the  upper  teeth,  with  transverse  or  horizon- 
tal section  through  the  base  of  the  pulp  chamber  in  the  crown,  viewing  the  entrance  to  the  canals 
of  the  several  roots,  while  the  same  letters  in  Fig.  2  represent  the  lower  series  in  the  same 
manner. 

Fig.  3  represents  the  upper  teeth,  with  the  transverse  or  horizontal  section  made  below  the 
largest  diameter  of  the  pulp  chamber  and  through  the  canals  after  they  have  diverged  from  the 
central  chamber,  but  before  the  roots  into  which  they  run  have  in  the  molars  bifurcated. 

Fig.  4  in  like  manner  represents  the  lower  series,  well  illustrating  the  flattened  or  compressed 
condition  of  the  canal  in  anterior  roots  of  the  molars  and  the  division  of  the  chamber,  as  is  fre- 
quently found  in  the  roots  of  the  lower  incisors. 

The  letters  a  a,bb,  c  c,  d  d,ff,  dd  and  e  e  (Fig.  3)  represent  the  relative  shapes,  whether  circu- 
lar, oval,  or  flattened,  of  the  pulp  canal  in  the  roots  of  the  upper  central  and  lateral  incisors, 
the  canines,  the  first  and  second  bicuspids,  and  the  first,  second,  and  third  molars,  while  the 
same  letters  in  Fig.  4  represent  the  relative  shapes  of  the  pulp  canal  in  similar  teeth  in  the 
lower  series. 

1  These  figures  are  taken  from  v.  Carabelli's  Anatomie  des  Mundes. 


Fig.  389. 
(For  description,  see  page  427.) 


'^^^^^(^^^a*   a. 


^-^ 


=?^ 


428 


Fig.  390. 

(For  description,  see  page  427. ; 


429 


Fk;.  3'.)1. 
(For  descriptiun,  suo  page  4'J7.) 


430 


FORMS  OF  PULP  CHAMBERS  AND  CANALS. 


431 


I^.  Mercuric  chlorid, 
Thymol, 
Acid,  carbolic, 
Acid,  tannic, 
Morph.  niur., 
Ol.  menth,, 
Ol.  cassise. 


da.  2.0  grams ; 

da.  1.5  gram  ; 

cici.  q.  s.  to  make  stiff  paste. — M. 


"  A  tannate  of  mercury  is  formed ;  it  is  insoluble,  and  but  little  pain 
is  caused  by  its  absorption." 

It  is  to  be  understood  that  these  preparations  and  this  method  of 
pulp  preservation  are  only  to  be  utilized  when  conditions  exist  which 
would  preclude  the  perfect  cleansing  and  filling  of  canals.  These  may 
be  economic  or  the  impracticability  of  thoroughly  extirpating  all  pulp 
remnants.  Failing  in  perfect  extirpation,  the  paste  is  to  be  packed  into 
parts  where  the  irremovable  pulp  remnants  exist. 

Formalin  and  its  isomeric  modification,  paraform,  have  been  used  as 
mummifying  agents,  with  reported  satisfactory  results,  but  the  use  of 
these  substances  as  mummifying  agents  is  still  in  the  stage  of  exjjeri- 
mental  study.  The  irritating  nature  of  formalin  suggests  caution  in 
its  permanent  application  to  pulps  or  pulp  canals,  as  several  cases  of 
chemical  necrosis  of  tissues  about  the  teeth  have  been  reported  from  the 
injudicious  use  of  the  drug  in  question. 

Topographical  Anatomy  of  the  Pulp  Chambers  and  Oanals. 

A  familiarity  with  the  topographical  anatomy  of  pulp  chambers  and 
canals  is  an  essential  preliminary  to  their  proper  opening  and  cleansing. 
Figs.  389,  390,  and  391  (see  pp.  428-430)  illustrate  the  average  pulp- 
chamber  forms. 

The  following  outline  figures  (Figs.  392-427)  are  exact  reproductions 


Fig.  392. 


Fig.  393. 


s 


Upper  central  incisor. 


Upper  lateral  incisor. 


of  sections  made  of  typical  teeth  which  have  been  shown  by  comparison 

with  numerous  other  sections  to  be  about  the  average  anatomical  forms. 

The  Upper  Central  Inoisor. — The  pulp  chamber  (Fig.  392)  approxi- 


432 


THE  TREATMENT  AM)   FILLING    OF  ROOT  CANALS. 


mates  in   form   that  of  tlic  tooth  itself.     The  oj>ening  of  the  eanal  is 
seen  to  be  almost  circular,  and  in  the  eentr.il  axis  of  the  tooth. 

Upper  Lafo'df  Incifior. — The  chamber  of  the  lateral  ineisor  (Fig.  39o) 
has  a  similar  form  ;  the  canal  exhibits  a  tendency  to  diverge  from  the 


Fio.  394. 


Fio.  395. 


Ftg.  396. 


Upper  lateral  incisors  (Ottolengui). 

straight  line  toward  the  aj^ical  end  (see  Figs.  394-396).     The  entrance 
to  the  canal  is  nearly  oval. 

Upper  Canine. — The  chamber  of  the  up})er  canine  is  large  and  open 
and  has  an  elliptical  canal  entrance  (Fig.  397).     The  root  of  this  tooth 


Fig.  397. 


Fig.  398. 


Fig.  399. 


Upper  canines. 


may  also  deflect  from  the  line  of  the  general  axis.     In  rare  cases  a 
bifurcation  of  the  root  is  seen  (Figs.  398,  399). 


Fig.  401. 


Fig.  402. 


Upper  first  bicuspids. 

Tlie  upper  first  bicuspid  very  commonly  exhibits  a  bifurcation  of 
the  roots  which  may  extend  to  any  distance  toward  the  crown  (Fig.  400). 
At  its  entrance  the  pulp  canal  has  a  dumb-bell  form,  the  handle  of  the 
dumb-bell  being  much  attenuated.  The  distinct  canals  may  begin 
almost  at  the  base  of  the  chamber,  or  be  evident  only  near  the  apices 


FORMS  OF  PULP  CHAMBERS  AND   CANALS. 


433 


of  the  roots.  Two  distinct  canals  may  be  present  even  in  the  absence  of 
bifurcation  of  the  root.  The  roots  of  this  tooth  may  be  much  curved. 
Fig.  401  presents  a  condition  occasionally  seen  :  a  trifurcation  of  the 
root  of  a  bicuspid.  Fig.  402  represents  a  section  through  the  buccal 
roots;  Fig.  402  also  shows  the  neck  section  of  the  tooth.  In  the  same 
mouth  were  found  three  bicuspids  exhibiting  the  same  condition.  The 
bifurcated  cuspid,  Fig.  399,  was  from  the  same  denture. 

Upper  Second  Bicuspid. — Sections  of  two  typical  forms  of  upper 
second  bicuspid  are  shown  in  Fig.  403,  ct  and  b.  In  such  a  case  as  6 — 
far  from  uncommon — it  will  readily  be  seen  what  dangers  exist  as  to 
the  difficulty  of  perfectly  filling  the  flat  general  canal  beyond  the  ellip- 
tical obstruction.     The  neck  section  in  both  types  is  almost  alike. 

Upper   First   Molar. — The  neck   section  of  the   upper   first  molar 


Fig.  403. 


Fig.  404. 


Upper  second  bicuspid. 


Upper  first  molar. 


(Fig.  404,  a)  shows  a  free  entrance  to  the  palatal  root;  the  anterior 
buccal  root  has  a  triangular  entrance,  near  the  mesio-buccal  angle  of 
the  tooth.  The  entrance  to  the  disto-buccal  root  is  very  small;  h,  Fig. 
404,  shows  a  section  through  the  buccal  roots  of  the  tooth.  Cases  are 
occasionally  seen  where  a  short  crown  is  associated  with  very  long  and 
divergent  roots  (Fig.  405). 


Fig.  405. 


Fig.  406. 


Fig.  407. 


Upper  molar. 


Upper  second  molars. 


Upper  Second  Molar. — The  arrangement  of  canals  in  the  second 
upper  molar  (Fig.  406,  a)  is  much  like  that  in  the  first;  except  that 
the  tooth  has  a  compressed  form  which  brings  the  canal  entrances  closer 
together.  A  section  through  the  buccal  roots  is  seen  in  Fig.  406,  h. 
This  tooth  occasionally  presents  marked  aberrations  in  the  location  and 

28 


434 


THE   TRKATMlCyT  AXD   FILLISC    OF  ROOT  CASALS. 


distribution  of  j)uli)  caiuJs.  Fiir.  407  illustrates  a  cast'  in  wliirh  there 
was  a  trifurcation  of  the  palatal  reot.  Other  abnormalities  of  the  canals 
of  upper  molars  are  shown  in  Figs.  40.S-413  (Ottolengni'). 


Fig.  408. 


Fig.  409. 


Vui.  no. 


Fig.  411. 


Fig.  412. 


Ki(i.  4l:i. 


Upper  molars  (Ottolengui). 


rjtpcr  TJdrd  Jlolar. — The  three  roots  of  the  upper  third  molar  are 
frequently  compres.sed  together,  giving  the  external  appearance  of  a 


Fig.  414. 


Upper  third  molars. 

single  round  conical  root.     In  many  instances  there  will  be  found  but 
a  single  large  canal,  as  in  Fig.  41  i,  (i.     The  rule  is  three  canals,  as 

Fig.  416.  Fig.  417. 


Fig.  415. 


9 


® 


Lower  incisors  iiiid  canine. 


.shown  in   Fig.  414,  b,  which  shows  also  a  section  through  the  buccal 
roots.     The  root  is  generally  curved  backward  more  or  less. 

1  Methods  of  FiUlny  Teeth. 


FORMS  OF  PULP  CHAMBERS  AND   CAXALS 


435 


Loum^  Anterior  Teeth. — Tlie  forms  of  the  canals  and  canal  entrances 
to  the  lower  anterior  teeth  are  shown  in  Figs.  415-417.  The  form  of 
partial  canal  bifurcation  shown  in  Figs.  416  and  417  is  noted  frequently 
in  longitudinal  sections  of  typical  teeth. 

Lower  Bicuspids. — The  forms  of  the  canals  in  the  lower  bicuspids 
are  much  alike  ;  the  canal  of  the  first,  however,  exhibits  a  tendency  to 
the  dumb-bell  form  of  entrance  (Figs.  418,  419).     Tortuosities  of  the 


Fig.  418. 


Fig.  419. 


Lower  first  bicuspid. 


Lower  second  bicuspid. 


canal  are  far  from  uncommon,  many  of  them  of  such  nature  as  to  ren- 
der full  and  complete  entrance  to  their  ends  next  to  impossible ;  in 


Fig.  420. 


Fig.  421. 


Fig.  422. 


Lower  bicuspids. 


Fig.  420  the  root  was  of  corkscrew  form,  in  Fig.  421  bent  at  right 
angles,  and  in  Fig.  422  a  short  crown  is  associated  with  an  extremely 
long  and  bent  root. 


Fig.  423. 


Lower  first  molars. 


Lower  First  3IoIar. — The  lower  first  molar  usually  presents  two 
canals  :  a  large  open  canal  for  the  posterior  root,  as  seen  in  Fig.  423, 
a  and  b,  while  the  anterior  root  presents  a  flat  ribbon-like  canal  very 


430 


THE   TREATMEyr  ASD   EILLING    OF  ROOT  CASALS. 


(lilliciilt  ot"  oiitnuicc.  A  tran>V(.'r.so  loii^itiuliiial  section  of  the  ante- 
rior root  is  shown  in  Fig.  423,  c.  In  order  to  effect  an  entrance  to 
the  majority  ot"  these  eanals,  it  is  al)solutely  essential  tliat  the  rubber 
(lam  be  aj)})lie(J  and  the  tooth  well  dried.  A  section  through  both  roots 
is  shown  in  Fig.  423,  6.  Not  uncommonly  two  distinct  anterior  canals 
are  found,  and  in  rare  instances  two  distal  roots  may  be  present,  as 
shown  in  Fig.  423,  d.  The  roots  of  this  tooth,  as  those  of  the  other 
lower  molars,  as  a  rule,  bend  backward.  Fig.  424  (from  Ottolengui) 
shows  an  exaggeration  of  this  bending. 

This  tooth  not  infrecjucntly  recjuircs  canal  treatment  before  the  roots 
are  fully  formed.     A  section  through  the  anterior  half  of  an  immature 


Fig.  424. 


Fig.  425. 


/'US-. 


Lower  first  molar. 


Lower  first  molar,  immature. 


tooth  is  shown  in  Fig.  425,  a;  through  the  posterior  half.  Fig.  42"),  b. 

Lower  /Second  Molar. — A  section  of  the  lower  second  molar  resem- 
bles that  of  the  first,  but  distinct  double  canals  in  the  anterior  root  are 
more  frequently  seen,  as  shown  in  the  section  of  the  anterior  half  in 
Fig.  426,  o) 

Lower  Third  Molar. — In  tlie  low^cr  third  molar  the  roots  are  fre- 
quently compressed  together,  exhibiting  bifurcation  toward  their  apices 
(Fig.  427). 


Fig.  426. 


Fig.  427. 


Lower  second  molar. 


Lower  third  molar. 


The  canals  of  any  tooth  may  exhibit  constrictions  or  flexions  at  any 
points  of  their  lengths.  Although  there  is  no  absolute  indication  as  to 
the  presence  of  flexions  or  abnormal  lengths,  an  examination  of  the 
overlying  gum  should  always  be  made,  Ayhen  lengths  and  irregularities 
may  possibly  be  determined  if  the  gum  tissue  and  alyeolar  wall  be  very 


INSTRUMENTS  FOR   CANAL    TREATMENT.  437 

thin.  If  any  of  these  irregularities  be  present  it  is  important  that  they 
be  discovered  and  additional  care  be  taken  to  eifect  a  complete  entrance 
to  the  canals. 

Instruments  for  Oanal  Treatment. 

The  description  thus  far  has  included  the  territory  to  be  operated 
upon  and  its  condition  as  regards  sepsis,  the  agents  commonly  employed 
to  produce  asepsis  and  antisepsis,  and  those  applied  to  maintain  these 
conditions.  The  first,  the  condition  of  the  root  canals  and  dentin  ;  the 
second,  the  various  antiseptics  employed  therein ;  the  third,  the  several 
materials  used  as  canal  fillings.  The  next  study  includes  the  instru- 
ments employed  and  their  specific  applications. 

The  first  are  enamel  chisels.  These  are  employed  to  cut  down  weak 
unsupported  enamel  walls  and  those  portions  of  enamel  removable  by 
such  instruments,  which  interfere  with  direct  access  to  the  pulp  canals. 
The  next,  burs,  of  several  forms ;  the  first,  that  variety  known  as  the  "  den- 
tate fissure  bur,"  for  cutting  enamel ;  next  rose,  inverted  cone,  and  oval 
forms  for  enlarging  cavities  and  removing  infected  dentin.  Next,  several 
forms  of  broaches,  canal  cleansers,  and  probes,  Gates-Grlidden  reamers 
for  enlarging  canals  ;  syringes,  pluggers,  and  finally  rubber  dam  and  the 
appropriate  selection  of  clamps. 

In  relation  with  this  latter  device,  it  is  to  be  recalled  that  demon- 
strations have  shown  the  saliva  to  be  a  highly  infective  fluid,  for  the 
reason  that  it  contains  a  variety  of  pathogenic  organisms  which  must  be 
excluded  from  pulp  canals  if  asepsis  of  these  passages  is  hoped  for.  No 
other  single  means  serves  so  effectively  as  isolation  by  the  rubber  dam. 

A  variety  of  syringes  will  be  required,  a  large  instrument  for  irriga- 
tion (Fig.  428),  to  wash  away  loose  debris  which  may  be  present  in  the 
cavities ;  smaller  syringes  will  be  required  to  accurately  place  definite 
quantities  of  medicaments  in  canals  (Figs.  429,  430,  and  431). 

Dentate  fissure  burs  are  invaluable  instruments  for  removing  por- 
tions of  sound  enamel  walls  which  interfere  with  direct  access  to  the 
root  canals.  Cutting  from  within  outward,  giving  the  bur  a  sawing 
motion,  a  groove  may  in  a  few  minutes  be  extended  across  the  occlusal 
face  of  a  molar  from  a  distal  cavity  to  a  point  directly  over  the  ante- 
rior root. 

Large  rose,  inverted  cone,  and  oval  burs  are  employed  to  remove 
the  dentin  which  may  obstruct  direct  entrance  to  the  canals ;  these  are 
as  a  rule  to  be  used  with  a  draw-cut,  placed  first  in  the  deepest  portion 
of  the  cavity,  and  while  revolving  drawn  toward  the  operator.  Care  is 
to  be  exercised  that  no  more  than  necessary  of  the  walls,  particularly 
the  floor  of  the  pulp  chamber,  is  to  be  burred  away,  to  avoid  mechan- 
ically weakening  the  tooth. 


408  TIIK   TREATMEST  AXP    r/LLL\<;    (>F  HOOT  ('AS M.S. 

The  hnuH'lics  cmplctycd  arc  of"  s('vcr:il  forms.     A  l)ro;icli  is,  acciiratolv 
.^peakino-,    an    instrument    desiiiiicd    to   enhiruc   openinirs ;    so    tliat    tlie 


Fi<;.  42S. 


Fui.  429. 


Fl(i.  430. 


'I 


Dental  syringe. 


Minim  syringe. 


J.  N.  Karrar's  alveolar  abscess  syringe. 


barbed  nerve  broach  is  not  employed  as  a  broach  but  as  a  pulp-extrac- 
tor (Fig.  432).  They  and  other  forms  of  extractors  (Fig.  433)  are  us>»i 
to  loosen  and  remove  debris  fi*om  canals. 


II^STRUMENTS  FOR   CANAL   TREATMENT. 
Fig.  431. 


439 


Bulb  syringe. 


The  toughness  of  these  instruments  is  remarkable.  They  are  so  tem- 
pered that  they  can  be  bent  in  any  desired  direction  and  Ayhen  properly 
manipulated  will  readily  follow  a  small  and  crooked  canal  to  the  apex 
without  danger  of  breaking  off.     Two  forms  :  with  sharp  hooks,  for 


Fig.   432. 


Barbed  pulp-extractors  and  holder. 

removing  the  pulp ;  and  straight,  with  the  ends  slightly  roughened, 
for  carrying  a  shred  of  cotton  in  cleansing  out  the  canal  or  treat- 
ing alveolar  abscess. 

The  next  instruments  employed  in  this  connection  are  what  are 
known  as  Donaldson's  pulp-canal  cleansers  (Fig.  434).  The  points  of 
these  pulp-canal  cleansers  are  reduced  so  as  to  enter  the  canal  readily, 
and  the  barbs,  which  are  cut  of  just  sufficient  depth  to  accomplish 
their  work,  are  arranged  spirally  around  the  shaft,  in  effect  forming  a 
screw,  so  that  no  two  cuts  are  exactly  opposite  each  other  (see  enlarged 
view,  a,  Fig.  434).  With  ordinarily  careful  usage  these  cleansers  will 
remove  the  pulp  substance  perfectly,  without  liability  to  be  broken  or 
to  become  fastened  in  the  canal.  If  at  any  time  the  instrument  does 
not  withdraw  readily  from  the  root,  a  turn  or  two  to  the  left  (unscrew- 
ing) will  at  once  release  it. 

They  are  made  of  tough  steel  piano-wire,  with  polished  vulcanite 
handles  ;  also  without  handles,  to  be  used  in  broach-holder. 

The  enlarged  view  of  the  Gates-Glidden  nerve-canal  drill  (Fig. 
435)  shows  the  peculiarity  of  the  safety  Glidden-point,  which  will  not 


440  THE  TREATMENT  AXD  FILLISG   OF  ROOT  CANALS. 

Fig.  433.  i''i"-  ■^^^^ 


Q 


Dr.  Donaldson's  pulp-canal  cleansers. 


enlarge  the  canal,  l)Ut  will  merely  guide 
the  drill  into  a  canal  no  wider  than  itself, 
until    it    reaches    the    root-apex,  through 
which  only  the  sharp  point  will  pass,  and 
produce  a   sensation    of  pain   that   gives 
notice  of  its  protrusion ;   yet,  unless  the 
foramen  is   wilder   than   the  base  of  the 
guide,    the     Gates    drill     will     not     cut 
flirouf/h    the  end    of  the    root — a  danger 
that    the     improved     drill    is     specially 
designed    to    avoid.       The    reamers    are 
made    with    their  thinnest  part    near  the 
junction    of    shaft    and    stem,    so    that 
should   fracture  of  the  tool  occur,  a  long 
piece    will    be  left    protruding   from    the 
tooth   and  may  be  readily  withdrawn. 
Using  the  series,  one  after  the  other,  with  care  and  judgment,  even 
a  tortuous  canal  may  be  suitably  enlarged ;  but  it  should  be  kept  in 
mind    that    many   roots    are    thin   at    their 
apical   portions,    and    their   canals,    if   much 
enlarged,     may    be    cut    through     laterally ; 
hence    the    advisability    of    employing    usu- 
ally  the  smaller  sizes   of  drills,   and  always 
the  smallest  first  when  the  canal  is  narrow. 
There  is  a  diversity  of  opinion  as  to  the 
wisdom  and  propriety   of  using   reamers   of 
any   kind    in    pulp    canals.       They   are    con- 
demned  in  toto   by   some  operators  ;   others  advise  their   employment 
in  all  cases. 


Dr.  Donaldson's  spring- 
tempered  nerve-bristles. 


Fig.  435. 


Improved  Gates-Glidden  nerve- 
canal  drill  for  engine  work. 


THE  CLEANSING   OF  CANALS.  441 

The  Cleansing  of  Canals. 

The  student  has  been  made  familiar  with  the  pathological  conditions 
he  is  called  upon  to  treat,  and  with  his  armamentarium,  including  the 
medicinal  agents  employed  in  their  correction,  and  is  now  prepared  to 
apply  the  one  to  the  other. 

It  is  most  apro])os  at  this  juncture  that  the  arguments  for  and  against 
the  reaming  of  root  canals  should  be  reviewed.  The  valid  objections 
urged  against  reaming  as  a  routine  practice  are,  first,  the  danger  of 
encroachment  upon  the  cementum  by  the  reamer ;  second,  the  breaking 
of  the  delicate  reamers  in  the  canal  and  the  difficulty  and  often  impos- 
sibility of  removing  the  fragment  when  such  accident  occurs  ;  third,  the 
liability  of  forming  false  canals  by  inability  to  confine  the  drill  to  the 
anatomical  canal.  The  argument  advanced  in  support  of  the  practice  is 
the  direct  and  ready  access  attained  by  it  to  the  length  of  the  canal. 
Owing  to  the  fineness  and  tortuosity  of  many  canals  it  is  impossible  for 
the  operator  to  assure  himself  that  he  has  thoroughly  cleansed  and  filled 
them  ;  by  accurately  and  properly  reaming  the  canals  directly  accessible 
to  fine  reamers  they  are  given  such  form  that  a  filling  may  be  placed 
with  a  reasonable  assurance  that  the  apex  is  hermetically  sealed.  It  is 
urged  that  as  many  roots — notably  the  anterior  roots  of  lower  molars, 
the  anterior  buccal  roots  of  upper  molars,  the  roots  of  upper  bicuspids 
and  of  lower  incisors — have  a  flattened  form,  their  pulp  canals  have  a 
ribbon  form.  In  reaming  such  canals  there  is  danger  of  the  reamer 
impinging  upon  the  cementum  at  the  thin  portion  of  the  root.  The 
advocate  of  root  reaming,  therefore,  advises  in  such  cases  the  employ- 
ment of  Donaldson's  canal  cleansers  to  scrape  away  the  canal  walls, 
enlarging  them  uniformly. 

The  danger  of  breaking  reamers  is  always  an  imminent  one,  al- 
though such  accidents  are  commonly  due  either  to  poorly  made  or 
imperfectly  tempered  instruments,  or  to  carelessness  upon  the  part  of 
the  operator.  Even  the  most  skilful  must  be  ever  on  the  alert  to  detect 
any  unusual  resistance  oiFered  to  the  advance  of  the  reamer.  This 
danger  increases  if  the  direction  of  the  canal  diverges  from  a  straight 
line.  It  is  obvious  that  with  any  instrument  which  is  being  rotated,  its 
point  must  be  kept  in  line  with  its  shaft  to  minimize  the  strain  on  the 
part  immediately  above  the  cutting  portion. 

The  employment  of  reamers  is  therefore  advised  only  in  nearly  straight 
and  rounded  roots  ;  the  central  idea  to  keep  in  mind  is  that  reamers  are 
employed  merely  to  uniformly  enlarge  canals  which  already  exist,  never 
to  form  new  ones.  Root  canals  which  have  a  flattened  form  are  en- 
larged by  means  of  the  cleansers,  using  progressively  increasing  sizes, 
and  supplementing  their  action  where  and  when  necessary  with  sulfuric 


442 


THE  TREATMENT  AXD   FIl.LINd    OF  ROOT  CANALS. 


Fig.  4.")t). 


acid,  as  advisi'd  in-  I)r.  .1.  II.  Callaliaii.'     This  method  is  nlVrcat  value; 

it  fiiniislios  a  means  for  enterinii;  and  thoroiio;hly  clejuisiiii;  and  enhirg- 

ing  canals  which  hef'ore  its  introduction  were  regarded  as  impossible  of 

entry. 

It  has  no  doubt  been  observed  by  every  operator,  how  seldom  roots 

which  have  been  well  prepared  for  artificial  crowns  of  the  post  variety 
l)ecome  the  seat  of  pericementitis.  This  fact  sug- 
gests tliat  the  mechanical  removal  of  the  existing 
boundary  walls  of  the  root  canals,  by  removing 
those  })ortions  of  dentin  invaded  by  septic  organ- 
isms may  lessen  the  opportunity  of  sepsis.  Miller 
has  shown  -  that  this  infection  of  dentin  about 
canals  is,  as  a  rule,  superficial  (Fig.  437).  The 
observations  made  in  the  essay  of  Dr.  Miller 
show  also  that  any  danger  to  the  lateral  peri- 
cementum by  invasion  of  the  dentinal  tubules 
leading  from  the  root  canal  is  remote  in  the 
extreme.  Infection  to  some  depth  does  occur, 
however  (Fig.  436).  It  is  undisputed  that  the 
source  of  septic  infection  of  the  pericementum 
is  from  the  canals  by  way  of  the  apical  foramen, 

Fig.  487. 


il-ri' 


m^ 


Fis.  4o6.— SectDF  of  a  cross  section  from  a  diseased  root:  a,  cement;  b,  stratum  granulosum ; 
c,  very  narrow  and  finely  branched  tubules  ;  d,  infecte<l  district.  (X  150.) 

Fig.  437. — Dentin  from  the  root  of  an  abscessed  tooth,  showing  the  penetration  of  cocci  to  a 
depth  of  about  (",,  mm.  {,la  in.).    The  side  a-6  bordered  upon  the  canal.  (X  1000.) 


Proc.  Ohio  Staie  Dental  Society,  1894. 


Dental  Comnos,  1890,  p.  353. 


THE  CLEANSING   OF  CANALS.  443 

and  if  the  tract  there  represented  be  made  aseptic  no  trouble  need  be 
feared. 

As  the  object  in  all  succeeding  operations  is  to  remove  and  not  to 
institute  a  septic  condition,  care  must  be  exercised  that  no  septic  organ- 
isms be  introduced  by  the  operator  into  the  field  of  operation.  The 
first  step  is  therefore  the  rendering  aseptic  of  this  field.  The  teeth 
should  be  cleansed  first  with  a  brush  and  soap,  then  the  mouth  be  rinsed 
with  an  antiseptic,  as  3  per  cent,  pyrozone,  10  per  cent,  solution  of 
meditrina,  or  a  lilac-colored  solution  of  potassium  permanganate.  The 
instruments  are  to  be  sterilized,  and  to  effect  this  object  an  excellent 
means  is  by  dipping  the  meclianically  cleansed  instruments  in  strong 
ammonia  water.^  If  any  food  or  pulp  debris  occupy  the  pul]>  chamber  it 
is  to  be  washed  away  with  the  antiseptic  employed  to  sterilize  the  mouth. 
The  rubber  dam  is  adjusted,  and  direct  sterilization  of  the  canals,  and, 
when  indicated,  of  the  tissues  at  the  apex  of  the  root,  is  to  be  attained. 

Method  of  Entrance  to  Canals. — The  first  step  or  stage  of  the 
operation  is  the  gaining  of  direct  and  free  access  to  every  canal  of  the 
tooth.  This  may  at  times  appear  to  involve  the  removal  of  an  undue 
amount  of  the  crown  of  the  tooth.  Unfortunately  this  is  true,  but 
efforts  at  the  conservation  of  too  much  of  the  crown  structures  and 
form  are  frequently  followed  by  incomplete  cleansing  and  filling  of  the 
canals.  This  latter  is  the  greater  evil  of  the  two,  so  the  cutting  away 
of  the  crown  is  always  to  be  done  when  necessary  to  accomplish  the 
end  in  view. 

In  the  vast  majority  of  cases  in  which  it  is  necessary  to  remove  a 
putrescent  or  septic  pulp  the  carious  process  has  invaded  the  crown  of 
the  tooth  extensively  ;  the  cavity  of  decay  is  therefore  excavated  until 
perfectly  free  from  carious  dentin ;  weak  enamel  walls  are  dressed 
away  by  means  of  enamel  chisels,  and  usually  direct  access  to  the  pulp 
chamber  is  gained.  This  is  still  insufficient ;  the  cavity  must  be 
opened  so  that  the  finest  size  of  canal  bristle  can  be  carried  directly  to 
the  apex  of  the  root  without  danger  of  fracturing  the  instrument. 

In  central  incisors,  as  the  carious  cavities  usually  open  upon  the 
approximal  surfaces,  entrance  is  gained  to  the  pulp  chamber  by  extend- 
ing at  the  palatal  aspect  of  the  cavity  a  groove  from  the  cavity  to 
over  the  entrance  of  the  pulp  chamber  (a.  Fig.  438). 

The  same  rule  is  observed  with  the  lateral  incisors  and  canines. 
Should  the  pulp  have  died  subsequently  to  the  insertion  of  fillings 
which  are  mechanically  faultless,  entrance  to  the  pulp  canal  is  made  in 
the  basilar  pit  (b,  Fig.  439).  For  canines  the  opening  is  made  at  a 
higher  point,  about  one-third  the  way  toward  the  cutting  edge.  These 
openings,  while  they  should  be  large  enough  to  afford  free  access  to  the 

^  See  also  Chapter  IV. 


444 


THE   TREATMEXT  AXD   FILLING    OF  ROOT  CANALS. 


caiml^,  should  iu»t  he  iiuulc  so  lar^c  as  to  wcakiii  the  ci'own,  or  tlierc  la 
dang;er  ol"  iVacturiue:  it  wlicn  in  pliysiological  use. 

Cavities  in  l)ifnsj)i(ls  invading-  the  |)id|)  arc  usually  upon  the  ap- 
j)ro\inial  surlaccs  ;  tlicy  arc  to  he  extended  over  the  oeelusal  face  of 
the  tooth  until  access  to  the  canals  may  be  had  (sec  Fig.  440). 


Fig.  4;W.       Fig.  439. 


Fig.  440. 


® 


Cavity  in  bicuspid. 


Fig.  441. 


i 


The  same  procedures  are  to  be  followed  in  molar  teeth.  In  lower 
molars  if  the  carious  cavity  be  upon  the  distal  wall,  it  is  to  be  artificially 
lengthened  across  the  occlusal  face  until  the  probe  may  be  carried 
directly  into  each  canal  (Fig.  441,  a) ;  the  same  method  is  pursued  if 
for  a  mesial  cavity.  In  upper  molars,  especial  care  is  required  to  gain 
primary  access  to  the  anterior  buccal  root,  and  tooth  structure  must  be 
cut  away  until  this  access  is  secured  (Fig.  441,  b).  Should  the  carious 
cavities  open  upon  the  buccal  faces  of  the  posterior  or  lingual  faces  of 
the  anterior  teeth,  the  upper  cavity  edge,  that  farthest  from  the  gum, 
must  be  extended  toward  the  cutting  edge  of  the  tooth  until  a  bent 
probe  may  be  readily  passed  to  the  apex  of  each  root  (Fig.  441,  r).  In 
operating  upon  many,  or  most,  of  the  canals  of  the  posterior  teeth  it  is 
necessary  to  bend  the  l)ulp  extractor  or  canal  cleanser  until  it  is  almost 
or  quite  at  a  right  angle  with  the  instrument  carrier. 

In  the  six  anterior  lower  teeth  where  openings  are  to  be  made  in 
them  in  the  absence  of  large  cavities  of  decay,  entrance  is  effected 
through  the  lingual  wall. 

The  advice  of  Dr.  J.  Foster  Flagg  is  appended,  as  to  the  position 
of  tap  openings  to  be  made  in  the  several  teeth,  when  the  teeth  if 
carious  have  not  the  carious  cavity  in  such  position  as  to  afford  access 
to  the  pulp  chamber  : 

"  By  means  of  a  diamond  drill  or  an  inverted  cone  bur,  a  rough 
spot  is  made  in  the  centre  of  the  face  to  be  jierforated  ;  this  prevents 
sli])ping  of  the  spear-pointed  drill  which  is  then  employed  to  enter  the 
pulp  chamber.  The  outlines  of  the  chamber  are  to  be  obliterated  with 
burs."  The  dentate  bur  is  a  most  effective  means  of  enlarging  such 
openings.     "The  o})ening  is  to  be  enlarged  until  a  fine  probe  may  be 


TREATMENT  OF  CANALS.  445 

passed   into  each   canal ;   the   teeth    are   tapped  in   the    following   sit- 
uations : 

Upper  Teeth. — Centrals  and  laterals  :    On  the  lingual  face. 

Canines  :  On  the  tuberosity,  or  disto-labially. 

First  or  second  bicuspids  :  On  occlusal  or  buccal  face. 

First  molars  :  On  occlusal,  or,  as  a  second  choice,  on  buccal  face. 

Second  molars  :  On  occlusal,  mesio-occlusal,  or  buccal  face. 

Third  molars  :  On  mesio-occlusal  face. 

Lower  Teeth. — Centrals  and  laterals  :  On  lingual  face  just  posterior 
to  cutting  edge. 

Canines  :  On  disto-labial  portion  near  the  gum. 

Bicuspids  :  On  mesio-buccal  face. 

First,  second,  and  third  molars  :  On  mesial,  buccal,  or  mesio-occlu- 
sal face." 

Treatment  of  Canals. 

The  tooth  and  adjacent  teeth  being  isolated  by  the  rubber  dam, 
direct  access  to  each  canal  having  been  gained,  the  tooth  having  its 
walls  sterilized  by  flooding  the  enlarged  pulp  chamber  with  a  reli- 
able germicide,  and  each  instrument  which  has  been  or  is  to  be  used 
being  sterilized,  the  subsequent  procedures  depend  entirely  upon  the 
condition  of  the  pulp  chamber,  canals,  and  dentin  (and  perhaps  the  peri- 
cementum), as  regards  sepsis.  One  of  the  several  conditions  described 
in  the  opening  of  the  chapter  is  present ;  which  of  these  it  is,  governs 
the  therapeusis. 

First :  A  case  in  which  the  pulp  has  been  intentionally  devitalized  and 
extirpated.  The  pulp  having  been  removed  en  masse  it  has  carried  with 
it,  provided  of  course  no  organisms  have  been  introduced  during  or  subse- 
quent to  its  extirpation,  all  of  the  sources  of  infection.  The  remote 
danger  is  now  the  existence  of  small  fragments  of  pulp  tissue  which 
if  unremoved  may  form  a  soil  for  the  development  of  organisms  obtain- 
ing entrance  to  them ;  or  blood  may  have  escaped  into  the  canals  where 
the  dead  pulp  was  torn  from  its  connection  at  the  apex.  The  hemorrhage 
may  be  reduced  to  a  minimum  and  the  operation  of  pulp  extirpation  in 
most  cases  be  rendered  quite  bloodless  by  the  use  of  one  of  the  various 
preparations  of  suprarenal  extract  in  combination  with  the  local  anes- 
thetic as  an  application  to  the  pulp  tissue  previous  to  its  removal.^ 
Where,  however,  any  exudation  of  blood  or  plasma  takes  place,  it  must 
be  removed  along  with  any  remaining  organic  debris. 

Hydrogen  dioxid,  being  the  agent  which  will  most  quickly  and 
effectively  disorganize  the  blood  corpuscles,  is  carried  into  the  canals 
and  permitted  to  act  for  a  few  minutes,  when  it  is  absorbed  by  means  of 

'  See  Chapter  ,  p. 


446 


THE  TREATMENT  AST)   FILLISG    OF  ROOT  CANALS. 


cotton,  or  taper  twists  of  bibulous  paper  ;  tlien  canal  cleansers,  be^innin<; 
witii  the  smaller  sizes,  are  employed  to  scrape  the  walls  of  the  canals  free 
of  anv  adherent  pidp  shreds  or  odontoblasts  which  may  have  been  torn 
off  when   the   pulp  was   removed.     Larger  sizes  are  to  succeed   these 
until  the  caliber  of  the  canal  is  made  larger  and  smooth.     If  it  be  a 
roiMid   root   and    there   be   any  interference   with    the  passage  of  these 
instrunu'Uts  to  the  apex  of  the  root,  it  is  evident  that  tlu'  sanu>  difficulty 
would  be  found  in  carrying  filling  material  to  its  ajx-x.     A  judicious 
reaming  of  the  root  removes  this  difficulty  and  is  therefore  done.     That 
size  of  the  Gates-(jlid<len  reamer  which  will  enter  the  canal  readily  is 
revolved  by  hand,  or,  if  in  the  engine,  is  revolved  very  slowly,  stopping 
the  moment  anv  resistance  is  felt.     The  reamer  is  frequently  withdrawn 
to  remove  the  debris  which  collects  behind  it.     As  soon  as  resistance 
is  felt,  a  fine  canal  cleanser  is  passed  beyond  the  point  and  the  walls 
scraped,  when  the  reamer  is  reapplied  ;  this  alternation  of  instruments 
is  continued  until   sensitivity  shows  that  the  point  of  the  reamer  has 
reached  the  pericementum.     The  next  size  of  reamer  is  then  employed 
to  enlarge  the  canal  uniformly.     As  soon  as  a  canal  is  reamed  a  tem- 
porarv  dressing  of  alcohol  on  cotton  is  placed  in  it  to  prevent  the  ingress 
of  debris  from  other  canals — tliat  is,  if  it  be  a  tooth  having  two  or  more 
roots.     In   upper   molars,  the   palatal,  and  in  lower  molars  the  distal, 
root  is  to  be  first  cleansed  and  dressed.     If  the  subject  of  o])eration  be 
a  single-rooted  tooth,  preparation  is  now  made  for  hermetically  sealing 
the  apex  and  filling  the  canal ;  if  a  multi-rooted  tooth,  the  canal  next  in 
size  is  entered  if  the  root  be  round  as  evidenced 
by  the  general  shape  of  the  canal.     For  example, 
the  anterior  roots  of  lower  molars,  the  buccal  roots 
of  upper  molars  or  of  bicuspids,  which  exhibit  a 
round  opening,  have    usually  but    not    always  a 
rounded  body  ;  those   showing  a  ribbon-like  out- 
line are  likely  to  have  a  corresponding  outward 
form.     Any  efforts  at  reaming  such  canals  should 
be    confined    to    that   portion  showing  a   roiuKh-d 
opening  ;  thus,  if  a  lower  molar,  the  finest  reamer, 
rotated  by  hand,  the  device  of  Dr.  "\V.  AV.  Walker 
(Fig.  442),  is   employed   to  enter  and  enlarge  the 
buccal  and  lingual  extremities  of  the  ril)bon-like  canals, 
enlarging  should   be   done  with   the   canal   cleansers.     The   same   rule 
applies  to  the  buccal  roots  of  upper  molars  and  to  bicuspids.     When 
any  doubt  exists,  the  enlarging  should  always  be  done  with  the  cleansers 
in.stead  of  the  reamers. 

Not  infre(|uently  cases  are  found  in  whieli  the   root  canals,  or  one 


Fig.  442. 


Iker  pulp-caiial 
reamers. 

Anv  furtlier 


TREATMENT  OF  CANALS.  447 

of  them,  may  have  such  contracted  caliber  as  to  refuse  entrance  to  the 
finest  canal  cleansers.  As  a  rule,  such  canals  will  be  found  in  the  buc- 
cal roots  of  upper  molars  and  the  anterior  root  or  roots  of  lower  molars  ; 
occasionally  the  bicuspids,  particularly  the  upper  first  bicuspids,  will 
exhibit  this  condition.  It  is  in  such  cases  that  the  method  of  cleansing 
and  enlarging  introduced  by  Dr.  Callahan  will  be  found  effective.  A 
rose  bur  is  employed  to  form  a  small  pit  of  which  the  entrance  of  the 
pulp  canal  is  the  centre.  In  this  pit  a  drop  of  sulfuric  acid,  50  per 
cent,  solution,  is  placed ;  immediately  upon  the  contact  of  the  acid  the 
finest  size  of  Donaldson  canal  cleanser  is  passed  as  far  as  it  will  go  into 
the  canal,  the  cleanser  is  inserted  and  partially  withdrawn,  scraping 
away  the  calcium  sulfate  formed  by  the  action  of  the  acid  upon  the  cal- 
cium salts  of  the  tooth.  The  acid  is  quickly  neutralized  and  fresh 
applications  are  made  drop  by  drop,  the  scraping  and  pumping  with  the 
cleanser  being  continued  until  the  point  of  the  instrument  is  felt  to 
reach  or  pass  the  apical  foramen.  Any  organic  matter,  such  as  filaments 
or  minute  fragments  of  pulp  tissue,  which  may  have  been  present  in  the 
canal  is  destroyed.  This  applies  also  to  organic  matter  undergoing  de- 
composition or  to  organisms  which  may  be  present.  As  there  is  no 
marked  degree  of  force  required  in  the  operation  it  may  be  pursued 
even  in  cases  of  pericementitis  or  acute  abscess,  to  gain  direct  and  free 
entrance  to  the  seat  of  morbid  action,  the  focus  of  germ  development. 

In  the  event  of  the  operator  being  unable  to  detect  through  instru- 
mental means  the  openings  of  minute  canals.  Dr.  Callahan  advises  that 
a  pellet  of  cotton  containing  a  minute  portion  of  acid  be  placed  over  the 
probable  situation  of  each  canal  and  sealed  in  over  night.  The  follow- 
ing day,  when  the  rubber  dam  is  applied  and  the  cavity  dried,  the  spot 
of  application  of  acid  will  be  represented  by  a  small  white  area,  in 
which,  if  a  canal  entrance  exist,  it  will  be  represented  by  a  black  dot. 
A  pit  is  made  at  this  point  and  acid  is  applied,  when  entrance  by  cleansers 
is  attempted ;  should  failure  to  gain  entrance  result,  it  is  most  probable 
that  the  canal  is  almost  or  quite  obliterated  with  secondary  deposits 
formed  by  a  receding  pulp,  hence  no  future  sepsis  is  probable.  As 
soon  as  the  cleanser  is  felt  to  touch  or  pass  the  a])ical  foramen  the 
canals  are  syringed  out  with  a  saturated  solution  of  sodium  bicarbonate. 
Carbon  dioxid  is  disengaged,  which  drives  the  debris  left  in  the  canals 
into  the  pulp  chamber,  and  the  acid  is  neutralized. 

Thus  far  has  been  described  the  entrance  to  and  thorough  cleansing 
and  uniform  enlarging  of  canals  of  a  tooth  from  which  the  intentionally 
devitalized  pulp  has  been  extracted  ;  the  immediate  question  is,  What 
treatment  shall  now  be  pursued  ?  Owing  to  the  method  of  pulp  with- 
drawal, the  contents  of  the  dentinal  tubules  are  as  yet  chemically  un- 
changed ;    and  it  scarcely  requires  argument  to  demonstrate  that_,  can 


448  THE  TREATMENT  AND    FfLLIXr;    OF  ROOT  CANALS. 

they  ho  kept  in  ;i  i^tahlo  coiKhtion,  they  constitute  the  l)e.^t  inateiial  tor 
occupaiK'v  of  the  tubules.  Examining:  the  list  of  inccncaiucnts  appliea- 
l)le  as  pn'servatives  zinc  ehlorid  is  the  airent  fixed  upon  as  the  one 
whieh  will  best  ])roeure  an  unehan<:;eal)le  eouditiou  of  the  cDntcnts  of 
the  tubules.  The  experiments  of  Prof.  Jas.  Truman  '  have  >ho\vn  that 
this  a_i]:ent  (piiekly  dilfuses  throu^jh  a  eapillarv  tube  eontainini;  albumin, 
eonvertiui;  it  into  a  whitish  eoajfulum,  an  albuminate  of  /ine,  which 
every  anatomist  knows  to  be  one  of  the  most  efficient  of  all  preserva- 
tives. Anatomical  specimens  of  parts  injected  with  a  zinc  ehlorid 
solution,  and  which  have  been  subjected  to  all  the  conditions  known  to 
favor  the  development  of  putrefaction,  remained  unchanged  after  the 
lapse  of  years.  It  is  advised,  therefore — advice  endorsed  by  a  majority 
percentage  of  operators — that  a  solution  of  zinc  ehlorid  be  now  j)laced 
in  each  canal.  A  twist  of  absorbent  cotton  is  dipped  in  a  solution  of 
the  salt.  Should  the  apical  foramen  be  large,  a  weak  solution,  about 
10  per  cent.,  is  employed  ;  if  fine,  the  strength  of  the  solution  may  be 
40  per  cent.  Unless  carelessly  manipulated  or  too  great  an  excess  of 
the  coagulant  be  employed  there  is  but  little  danger  of  forcing  the  solu- 
tion beyond  the  apex  of  the  root.  After  about  ten  or  fifteen  minutes 
the  application  is  withdrawn  and  cotton  or  paper  cones  passed  in  the 
canal  to  absorb  any  excess  of  the  ehlorid  which  may  be  present,  and  the 
canals  are  now  ready  for  filling. 

The  use  of  formalin  as  an  ingredient  of  pulp-mummifying  pastes  has 
already  been  referred  to.  (See  p.  431.)  Caution  in  its  use  for  that  pur- 
pose was  suggested  because  of  the  marked  destructive  effect  which  it  has 
been  observed  to  produce  upon  living  tissue  when  a])plied  in  sufficient 
concentration  or  in  considerable  quantity  for  an  extended  period  of  time. 
As  a  topical  application  to  root  canals,  its  activities  can  be  controlled  with 
more  certainty  than  when  it  is  permanently  sealed  into  a  canal  as  an 
ingredient  of  mummifying  paste. 

Formalin  is  the  proprietary  name  for  a  40  per  cent,  aqueous  solution 
of  the  gas  formic  aldehyd  or  formaldehyd,  CHgO.  It  is  a  powerful 
diffusible  antiseptic  and  possesses  the  property  of  tanning  or  hardening 
proteid  substances,  forming  with  them  insoluble  compounds  which  appear 
to  possess  persistent  antiseptic  properties. 

For  rendering  the  contents  of  the  dentinal  tubuli  sterile,  fixed,  and 
unchangeable,  formalin  may  be  classed  as  fully  equal  in  value  to  zinc 
ehlorid,  while  for  the  treatment  of  infected  dentin  and  of  cases  where 
infective  invasion  has  reached  beyond  the  apical  foramen  to  the  periapical 
tissues,  the  diffusibility  of  formaklehyd  gives  it  a  decided  advantage  over 
all  other  sterilizing  agents. 

'  Proc.  Academij  of  Stomatology,  Philadelphia,  1894. 


THE  ROOT-CANAL  FILLING.  449 

In  cases  of  non-infected  canals  where  the  vital  pulp  has  been  surgi- 
cally extirpated,  the  previously  cleansed  canal  may  be  wiped  out  with  a 
broach  armed  with  cotton  Avhich  has  been  moistened  with  a  10  per  cent, 
solution  of  formalin  and  then  be  followed  by  immediate  root  filling  with 
safety.  Where,  however,  the  medicament  is  to  be  left  in  situ  as  a  canal 
dressing,  as  in  the  case  of  an  infected  canal  following  the  removal  of  a 
putrescent  pulp,  a  much  more  dilute  solution  should  be  employed.  One 
to  2  per  cent,  formalin  solution  in  quantity  no  more  than  sufficient  to 
dampen  the  cotton  dressing  may  be  loosely  sealed  in  a  septic  canal  with- 
out danger  of  producing  undue  irritation,  and  one  such  application  is  in 
many  cases  all  that  will  be  required  to  effect  thorough  disinfection  of  the 
root  canal  if  uncomplicated  by  chronic  apical  disturbance.  The  per- 
centage solutions  here  advised  are  to  be  understood  as  centesimal  parts 
of  the  40  per  cent,  aqueous  solution  of  formaldehyd  known  as  formalin, 
and  not  as  percentages  of  the  gas  itself. 

The  Root-canal  Filling. 

When  oxychlorid  of  zinc  has  been  determined  upon  as  the  perma- 
nent canal  filling,  the  preliminary  treatment  of  the  canal  with  zinc 
chlorid  solution  is  superfluous,  as  the  coagulating  and  antisejjtic  action 
of  the  zinc  chlorid  used  in  making  the  oxychlorid  cement  fully  answers 
the  purpose  in  the  short  period  of  time  elapsing  before  chemical  com- 
bination of  the  fluid  and  powder  results  in  a  hardened  body. 

Examining  the  available  statistics  regarding  the  several  materials 
which  have  been  employed  for  canal  filling  in  such  cases,  there  is  found 
a  greater  percentage  of  success — that  is,  a  fewer  number  of  cases  pres- 
ent subsequent  evidences  of  sepsis — when  zinc  oxychlorid  has  been  used. 
This  is  quite  in  accord  with  rational  therapeusis ;  the  material  is  capable 
of  hermetically  sealing  the  apex  and  is  unchangeable  in  the  conditions 
surrounding  it.  Its  antiseptic  action  probably  plays  little  or  no  con- 
tinued part,  disappearing  shortly  after  the  material  sets ;  it  is,  however, 
indisputable  that  when  this  material  has  been  employed  as  a  pulp  cap- 
ping it  has  not  infrequently  converted  the  entire  pulp  into  a  hyaline 
coagulum  Avhich  has  remained  permanently  aseptic. 

This  material  is  mentioned  first  on  account  of  the  ease,  readiness,  and 
certainty  with  which  it  may  be  placed. 

Gutta-percha  ranks  second  in  point  of  favor  as  a  canal  filling ;  this 
not  on  account  of  any  deficiency  of  specific  ]jroperties  contraindicating 
its  use,  but  there  is  not  the  same  certainty  of  accurate  jjlacement  and 
hermetic  sealing  as  with  the  oxychlorid.  Gold  and  tin,  the  remain- 
ing materials  which  have  found  any  extensive  employment  in  such 
cases,  are  open  to  the  same  common  objection,  viz.  difficulty  of  manipu- 
lation. 

29 


4o()  THK  TRKATMEST  ASI>   FILIJSU    OF  ROOT  CASALS. 

These  are  the  praetieally  irreiuovaljle  materials.  The  removable 
materials  which  have  been  recommended  are,  first — 

Cotton. — It  is  due  to  Prof.  J.  Foster  Flagg  that  this  substance  has 
been  extensively  employed,  not  as  a  filling  material  per  sr,  but  as  a 
metlium  holding  an  antiseptic.  The  variety  of  cotton  employed  is  the 
crude  uncarded  cotton  wool.  Dr.  Flagg  cites  as  a  proof  of  ihe  imper- 
meabilitv  of  this  material  when  pmperly  packed,  that  bales  of  cotton 
which  have  floated  in  sea-water  for  long  })eriods,  when  oiKMied  show  no 
evidences  of  moisture  in  their   interior. 

Evidence  regarding  the  value  and  danger  of  this  material  is  con- 
flicting. It  is  asserted  by  the  advocates  of  cotton  ctinal  fillings  that, 
properly  inserted,  they  remain  unchanged  for  long  periods,  are  readily 
packed  into  position,  and  if  necessity  demand  may  be  readily  removed. 
Those  who  oppose  the  use  of  cotton  assert  that  it  soon  becomes  filled 
with  pnxlucts  of  decomposition,  and  that  after  some  years  the  texture 
of  the  material  is  destroyed,  rendering  its  removal  very  difficult.  In 
conse(jnence  of  these  conflicting  opinions,  the  weight  of  evidence  being 
with  those  who  opjKtse  its  use,  cotton  has  found  but  limited  endorsement. 

The  other  removable  materials,  salol  and  paraffin,  are  innovations 
too  recent  to  determine  their  value  and  position  as  canal  fillings.  The 
reports  regarding  salol  are  sufficiently  e(»nflicting  to  warrant  advising 
its  use  only  in  conjunction  with  a  central  mass  of  gutta-percha  or  tin 
points  ;  the.  salol  filling  the  space  between  the  gutta-i)ercha  or  metal 
point  and  the  walls  of  the  canal. 

These  are  the  arguments  for  and  against  the  several  materials ;  the 
weight  of  evidence  being  largely  in  favor  of,  first,  the  oxychlorid  of 
^inc  ;  and  second,  gutta-percha. 

The  question  is,  now,  When  shall  the  canals  be  filled  ?  Shall  it  be 
done  immediately,  or  shall  a  period  be  permitted  to  elapse  for  assurance 
that  no  inflammatory  action  shall  arise  and  the  filling  be  a  bar  to  its 
jirompt  reducti(jn "?  There  are  two  causes  which  might  be  productive 
of  inflammatory  action  :  First,  the  dental  manipulations  of  removing 
the  pulj)  and  cleansing  the  canals  might  be  productive  of  sufficient 
irritation  to  give  rise  to  inflammatory  reacti«m  ;  in  that  event  the  open 
canal  would  afford  an  escape  for  inflammatory  effusions.  The  second 
danger  would  dej)end  up<»n  whether  septic  organisms  had  been  intro- 
duced or  had  not  been  thoroughly  destroyed  ;  their  sealing  in  the  canals 
might  be  productive  of  septic  inflammati<>n.  If  the  foregoing  mea.s- 
ures  of  cleansing  have  been  followed  it  is  scarcely  ]>ossible  that  any 
organisms  could  survive.  General  exj)erience  demonstrates  that  in  but 
a  small  percentage  of  ca.ses  does  the  pericementum  suffer  markedly  from 
traumatism  during  the  cleansing  and  sterilizing  of  canals,  so  tliat  th^ 


THE  ROOT-CANAL  FILLING.  451 

weight  of  evidence  clearly  teaches  that  such  canals  naay  be  filled  at  once, 
and  little  or  no  reaction  occur. 

Rational  surgical  principles  clearly  indicate  the  propriety  and  advan- 
tage of  immediate  root  filling  in  all  cases  where  a  sterile  condition  of  the 
canal  exists  and  where  there  is  absence  of  congestion  due  to  traumatic  or 
chemical  irritation  of  the  periapical  tissues.  The  increasing  disuse  of 
arsenical  preparations  for  devitalizing  the  pulp  and  the  substitution  of 
surgical  extirpation  of  the  pulp  under  local  anesthesia  are  eliminating 
one  fruitful  cause  of  irritation  to  the  retentive  tissues  of  the  tooth  root. 
Improved  methods  of  canal  treatment  and  the  introduction  of  reliable 
germicides  for  the  purpose  have  brought  the  problem  of  canal  steriliza- 
tion almost  within  the  limits  of  certainty. 

When  dealing  with  a  non-infected  pulp  canal  from  which  the  central 
organ  has  been  surgically  removed  under  proper  antiseptic  precautions, 
it  is  no  more  rational  to  delay  the  operation  of  root  filling  and  subject  the 
case  to  the  chances  of  infection  by  repeated  placing  and  removal  of 
dressings  than  it  would  be  to  leave  an  opening  for  drainage  in  an  abdom- 
inal section  where  pus  was  not  a  factor  in  the  case  previous  to  operation. 
It  has  been  said  by  eminent  surgical  authority  that  while  "  we  are  not 
responsible  for  the  germs  we  find  in  a  part,  we  are  responsible  for  those 
we  introduce  in  a  part."  The  repeated  dressing  of  a  root  canal  is  a 
fruitful  means  for  infecting  a  part  which  in  the  case  of  a  freshly  ex- 
tracted healthy  pulp  was  originally  sterile,  which  should  have  been  kept 
so  by  the  means  already  pointed  out  and  subsequent  infection  prevented 
by  a  root  filling  which  hermetically  seals  the  canal  and  obliterates  it  as  a 
means  of  carrying  infection  to  the  peridental  membrane. 

In  using  oxychlorid  as  a  canal  filling,  it  should  be  remembered  that 
freshly  mixed  zinc  oxychlorid  is  markedly  irritating  to  vital  tissues,  and 
it  is  well  to  place  between  the  paste  and  the  tissues  of  the  apical  region 
a  barrier  to  the  former.  This  may  be  of  gutta-percha.  A  very  fine 
cone  of  gutta-percha  about  one-quarter  inch  long  is  dipped  in  oil  of  euca- 
lyptus or  oil  of  cajuput  to  soften  its  surface  :  it  is  then  carried  to  the 
apex  of  the  root  upon  a  fine  probe  and  pressed  into  position.  Or,  a 
small  pellet  of  cotton  is  dipped  in  a  strong  solution  of  thymol  or  aristol. 
It  is  extremely  probable  that  when  the  freshly  mixed  oxychlorid  is 
placed  over  it,  the  cotton  becomes  converted  into  amyloid  which  her- 
metically and  permanently  seals  the  apical  foramen  ;  the  same  change 
occurs  in  the  cotton  upon  which  the  oxychlorid  is  carried  into  position. 
Slender  wisps  of  cotton  are  rolled  thin  enough  to  pass  readily  into  the 
canals.  A  thin  paste  of  oxychlorid  is  mixed,  the  cotton  wisps  are 
rolled  in  it  until  the  meshes  are  full,  when  the  extremity  of  a  w^sp  is 
caught  upon  the  end  of  a  long,  smooth,  and  slender  canal  plugger  and 
carried  up  the  canal  to  contact  with  the  guard  at  the  apex  ;  the  plugger 


452  77/ A'   TREATMKyT  AXD   FfLLfXC    OF  ROOT  CANALS. 

is  withdrawn  about  onoi'iylitli  ol'  an  inch,  and  that  Icnjrth  of  the  cotton 
is  crimped  upon  itself;  the  remainder  of  tlie  canal  is  pluij^ed  in  the 
same  manner  until  it  is  full,  when  the  surplus  length  of  the  cotton  is 
cut  off  and  bibulous  paper  is  j)ressed  a*rainst  the  canal  fillin<j  to  absorb 
the  surplus  zinc  chlorid.  The  floor  of  the  ]>ulp  chamber  may  be  covered 
with  the  stitfenintj:  paste  from  the  mixing  slab. 

A  method  by  which  cotton  fiber  loaded  with  the  oxychlorid  may  be 
carried  to  the  root  apex  with  great  accuracy  and  precision  is  as  follows  : 
The  smallest  size  Donaldson  bristle  with  smooth  sides  has  its  hooked 
end  cut  off  with  the  scissors  and  the  cut  end  made  flat  by  i-ul)l)ing 
lightly  upon  a  fine  Arkansas  stone.  This  may  be  readily  done  by 
grasping  the  bristle  very  near  to  its  point  between  the  thumb  and  index 
finger  and  lightly  rubbing  it  back  and  forth  u|»oii  the  surface  of  the 
stone.  The  bristle  is  then  laid  flat  upon  a  glass  slab  and  burnished 
from  heel  to  point  until  the  surface  is  perfectly  smooth  and  any  burr 
turned  upon  the  point  by  the  action  of  the  stone  is  fully  removed.  A 
few  fibers  of  cotton  wool  arc  then  hold  between  the  thumb  and 
index  finger  of  the  left  hand,  the  direction  of  the  fibers  being  in  the 
line  of  the  long  axis  of  the  index  finger.  The  point  of  the  prepared 
broach  is  then  laid  upon  the  cotton  fibers,  and  both  broach  and  cotton 
are  rolled  together  between  the  finger  and  thumb.  The  rolling  action 
of  the  finger  and  thumb  serves  to  felt  the  cotton  fiber  on  to  the  broach, 
and  should  be  continued  until  the  cotton  is  evenly  felted  over  the 
squared  end  of  the  broach.  The  whole  operation  is  done  by  the  left 
hand.  The  broach  is  not  twirled  into  the  cotton  with  the  right  hand  as 
is  ordinarily  done  where  a  roughened  cotton-carrying  probe  is  used. 
With  a  smooth  broach  and  the  cotton  fil)cr  felted  on  as  described,  the 
broach  may  be  pushed  fbrwartl  with  consideral)le  force  into  a  canal 
without  puncturing  the  cotton,  which  is  securely  carried  as  far  as  the 
broach  will  go.  On  account  of  the  smoothness  of  the  sides  of  the  broach 
it  may  be  easily  withdrawn  for  a  slight  distance,  and  then  engaging  in 
the  surrounding  cotton  it  is  used  as  a  plugger  to  pack  the  cotton  ahead 
of  it,  and  the  plugging  action  continues  until  the  material  is  all  packed 
in  place.  The  adjustment  of  the  cotton  to  the  broach  as  described  really 
forms  a  tube-like  arrangement  of  the  cotton  with  the  instrument  in  its 
central  lumen — an  arrangement  greatly  favoring  the  operation  of  carry- 
ing the  cotton  into  place  and  enabling  the  operator  to  use  the  cotton  or 
any  suitable  fiber  as  a  vehicle  for  canal  dressings  or  for  permanent  filling 
in  connection  with  the  oxychlori<l  of  zinc  cement. 

If  gutta-percha  be  the  material  selected  for  filling  the  canal,  a  careful 
examination  is  made  to  determine  whether  the  apical  foramen  be  com- 
])aratively  large  or  very  small  ;  in  the  latter  case  cliloro-jiercha  may  be 
first  pumped  into  the  canals ;  in  the  former  it  is  wiser  to  omit  the  fluid, 


THE  ROOT-CANAL  FILLING. 


453 


Fig.  443. 


owing  to  the  possibility  of  passing  it  through  the  apical  foramen.  In  all 
cases  where  a  canal  filling  is  to  be  made  of  gutta-percha  cones  it  is 
advisable  to  first  lubricate  the  walls  of  the  canal  with  one  of  the  anti- 
septic oils,  cinnamon,  eucalyptus,  or  cajupiit;  these  will 
facilitate  the  passage  of  the  point  to  the  apex,  and  as  sol- 
vents of  gutta-percha  will  soften  its  surface  and  permit  a 
closer  adaptation  to  the  canal  walls.  Should  the  apical 
foramen  be  found  large  enough  to  admit  the  pointed 
extremity  of  one  of  the  gutta-percha  cones,  the  end  of  the 
latter  is  cut  oif.  The  canal  is  lubricated  with  the  essential 
oil,  the  cone  itself  dipped  in  the  same  medium,  its  base 
caught  upon  the  end  of  a  canal  plugger,  and  it  is  passed 
carefully  into  the  canal  as  far  as  it  will  go,  when  the  plug- 
ger is  withdrawn  ;  blasts  of  hot  air  from  a  hot-air  syringe 
are  directed  against  the  exposed  end  of  the  cone  until  it 
is  softened,  and  it  is  then  pressed  firmly  into  position  by 
means  of  fine  pluggers.  A  sufficient  number  of  cones  are 
added,  softened  and  packed  in  position,  filling  the, canal 
flush  with  the  pulp  chamber. 

In  fine  tortuous  canals  it  is  the  usual  practice  to  first 
pump  them  full  of  thin  chloro-percha.  A  portion  of  the 
solution  is  caught  between  the  points  of  a  pair  of  Flagg's 
dressing  pliers  (Fig.  443)  and  carried  to  the  opening  of  the 
canal,  when,  if  the  points  are  opened,  the  drop  of  fluid  is 
deposited  there ;  it  is  then  pumped  into  the  canal  by  means 
of  a  fine  smooth  broach.  To  minimize  the  leakage  due  to 
the  shrinkage  of  the  chloro-percha  in  hardening,  it  is  ad- 
vised to  thrust  into  the  fluid  material  in  the  canal  as  large 
a  gutta-percha  cone  as  the  canal  will  admit.  Dr.  Otto- 
lengui  advises  that  the  pieces  of  silk  described  in  the 
beginning  of  the  chapter  be  used  and  an  end  left  project- 
ing into  the  pulp  chamber,  when,  should  removal  of  the 
filling  ever  become  necessary,  this  end  may  be  caught  and 
the  entire  filling  withdrawn. 

Should  it  be  designed  to  fill  the  canal  with  gold,  its 
exact  length  is  measured  by  placing  a  small  disk  of  rubber 
dam  over  a  canal  plugger,  inserting  the  plugger  in  the  canal 
and  carrying  the  plugger  point  to  the  apex.  The  floor  of  the 
pulp  chamber  engages  the  rubber  dam,  and  when  the  plugger 
])oint  has  reached  the  end  of  the  canal  the  little  gauge  piece 
of  rubber  dam  marks  its  exact  length.  Minute  pieces  of 
soft  gold  foil  are  cut,  and  one  by  one  are  carried  to  the  end  of  the  canal, 
the  rubber  upon  the  plugger  being  the  guide  to  completeness  of  access  to 


Flagg's  dress- 
ing pliers. 


454 


THE  TREATMENT  AND   FTLLiyC    OF  ROOT  CANALS. 


tilt"  r()(»t  apex.  Tliis  nictliod  is  to-day  rarely  iollowed.  I)r.  \\  .  S.  Ilow 
advises  the  use  of  shredded  tin  for  seaiiiiu  the  aj)iees  of  canals.  J^y  a  series 
of  fine  probes  the  canal  length  is  measured  (as  shown  in  I'^igs.  444—448), 


Fig.  444. 


Fifi.  445. 


Fk;.  44G. 


and  particles  of  shredded  tin  foil  are  carried  to  the  apex  and  impacted 
by  means  of  measured  plungers. 

Salol  and  paraffin  are  both  manipulated  after  one  manner.  A  very 
fine  probe  is  passed  into  the  canal  to  its  apex  ;  a  portion  of  the  ma- 
terial is  caught  between  the  beaks  of  a  pair  of  dressing  pliers  (Fig.  443) 
and  held  above  an  alcohol  flame  until  it  is  melted,  when  the  closed 
beaks  are  placed  in  the  canal  beside  the  probe,  and  opened,  and  the  fluid 
material  runs  into  the  canal.  Slowly  withdrawing  the  j)rol)e,  the  fluid 
runs  into  the  space  occupied  by  the  probe,  filling  the  canal  to  the  apex  ; 
it  is  advisable,  however,  to  warm  a  broach,  and  by  a  pumping  motion 


Fig.  447. 


Fig.  448. 


TREATMENT  OF  ROOT  CANALS   WITH  MUMMIFIED   PULP.    455 

insure  the  carrying  of  the  filling  to  all  parts  of  the  canal.  If  salol  be 
employed  a  cone  of  gutta-percha  of  such  size  as  may  be  readily  carried 
to  the  apex  should  be  thrust  into  the  fluid  material,  virtually  filling  the 
greater  portion  of  the  canal  with  gutta-percha.  Several  trustworthy 
observers  have  noted  a  disappearance  of  salol  from  canals  in  which  it 
has  been  placed ;  the  gutta-percha  minimizes  the  risk  attendant  upon 
such  disappearance.  The  gutta-percha  subserves  another  purpose : 
should  it  ever  be  necessary  to  remove  the  canal  filling,  blasts  of  warm 
air  directed  against  the  end  of  the  gutta-percha  may  be  made  to  melt 
the  salol  about  it,  when  the  cone  may  be  readily  withdrawn.  This 
melting  and  withdraw^al  are  more  quickly  accomplished  if  the  central 
mass  be  of  metal.  The  use  of  salol  as  a  root-canal  filling  is  better 
adapted  to  the  deciduous  than  to  the  permanent  teeth,  owing  to  its  lack 
of  permanency  in  some  instances,  as  already  stated. 

In  combination  with  paraffin  its  stability  is  greatly  increased  and  is  an 
effective  antiseptic  non-irritant  canal  tilling. 

Treatment  of  Root  Canals  with  Mummified  Pulps. 

The  remaining  member  of  the  aseptic  cases  is  that  of  mummified 
pulp.  So  long  as  these  cases  remain  perfectly  aseptic  they  give  rise  to 
no  symptoms  and  are,  as  a  rule,  uncovered  by  accident,  rarely  by  design. 

Their  usual  history  is  as  follows  :  At  some  time  (perhaps  years) 
before,  an  exposed  or  almost  exposed  pulp  has  been  covered  with  a  cap 
or  cavity  lining  of  the  oxychlorid  of  zinc.  They  have  remained  com- 
fortable thereafter.  At  some  subsequent  time  it  may  be  necessary  to 
open  the  tooth,  usually  on  account  of  recurring  caries :  the  total 
absence  of  dentinal  sensitivity  is  noted,  the  tooth  has  changed  color  but 
little,  if  at  all,  and  the  operator  burs  carefully  toward  the  pulp  to 
determine  its  condition.  (It  should  be  remarked  here  that  absence 
of  dentinal  sensitivity  in  a  tooth  having  normal  color  and  which  con- 
tains a  very  large  filling  is  an  indication  of  aseptic  death  of  the  pulp, 
and  the  operator  should  renew  all  of  his  antiseptic  precautions  as  to 
isolation  of  the  tooth  by  the  rubber  dam  and  complete  sterilization  of 
all  instruments  and  of  the  territory  of  operation.)  The  burxing  is  con- 
tinued without  any  evidence  of  sensitivity,  and  the  instrument  is  finally 
felt  to  pass  into  the  pulp  chamber.  There  is  no  odor,  no  escape  of 
fluid,  the  pulp  being  found  dry  and  shrivelled.  If  sterilized  pulp 
extractors  are  passed  into  the  canals,  the  remnants  of  the  pulp  may  be 
withdrawn,  exhibiting  none  of  the  usual  signs  of  decomposition  such  as 
odor  and  confluent  softening.  This  is  usually  the  case  when  pulps  have 
died  under  an  oxychlorid  of  zinc  capping,  the  zinc  chlorid  acting  as  a 
preservative  antiseptic. 


456  THE  TREATMENT  ASD   FT  LI.  I  NO    OF  ROOT  CAXALS. 

Even  wluMV  the  itiilj)  lias  not  boon  suUjccteil  to  the  action  of  zinc 
chloriil  and  Mhere  its  dcatli  lias  ocennvd  from  canses  wliicli  did  not 
include  access  of  <rernis  from  the  oral  cavity,  as  in  casi^s  of  traumatic 
dcatli  of  the  pulp,  it  is  highly  improbable  that  any  organisms  are  present, 
unless  they  should  have  been  introduced  by  the  operator  from  the  ex- 
terior. The  possibility  of  this  occurring  should  prompt  caution,  for  it  is 
the  experience  of  many  that  although  organisms  have  not  been  present 
in  the  canals,  when  introduced  from  without  they  find  a  fruitful  soil  for 
devcloj>ment.  Where  the  operation  of  opening  into  these  sterile  dead 
pul))s  has  not  been  done  with  the  strictest  antiseptic  precautions,  re- 
action indicating  infection  may  occur  within  a  few  hours  or  may 
be  delayed  for  perhaps  two  days.  This  condition  may  arise  even 
ill  connection  with  teeth  whose  pulps  have  died  under  a  capping  of 
zinc  oxvchlorid,  from  the  fact  that  the  quantity  of  /ine  c-hlorid  used  in 
the  capping  material  was  insufficient  to  completely  saturate  the  pulp 
tissue  and  render  it  permanently  antiseptic.  It  is  advisable,  therefore, 
to  cleanse  the  canals  with  some  powerful  and  penetrating  antiseptic  to 
destroy  any  chance  organisms  and  to  insert  a  probationary  though  jjcr- 
fect  root  filling  until  the  time  of  danger  has  passed.  The  antiseptic 
which  meets  the  indications  is  a  3  to  5  per  cent,  formalin  solution  or  the 
ethereal  25  per  cent,  solution  of  hydrogen  dioxid  known  as  jiyrozone, 
permitted  to  remain  in  the  canals  for  several  minutes.  The  canals  are 
then  dried,  and  for  the  temporary  filling  salol  is  the  rational  indication. 
At  the  expiration  of  three  days  if  no  evidences  of  pericementitis  are 
]>rescnt  the  operator  may  remove  the  salol,  rea})ply  the  antiseptic,  and 
fill  the  canals  with  oxychlorid  or  with  gutta-percha. 

It  should  be  made  an  invariable  rule  of  jiractice  never  to  open  a 
sterile  pulp  chamber  in  which  the  jjulp  has  l)ecome  devitalized  without 
applving  the  rubber  dam  and  flooding  the  surface  of  the  tooth  or  cavity 
with  a  powerful  germicide,  through  which  fluid  the  drill  should  be  made 
to  pass,  thus  absolutely  sterilizing  its  point  and  at  the  same  time  exclud- 
ing infective  organisms  from  the  canal. 

Septic  Cases. 
The  second  great  class  of  cases,  the  septic,  comprises  those  in 
which  the  pulp  has  undergone  some  extent  of  decomposition.  As  a 
rule,  the  first  organisms  w'hich  invade  pulp  tissue  are  the  staphylo^ 
cocci  and  streptococci,  which  find  a  suitable  habitat  in  the  live  pulp. 
Advancing  first  along  the  lines  of  the  veins,  their  toxic  waste  prod- 
ucts causing  inflammation,  tlie  organisms  invade,  peptonize,  and  liquefy 
the  inflammatory  effusions.  As  these  cocci  advance  toward  the  apex 
of  the  root,  the  necrotic  and  altered  tissues  which  are  left  behind 
become  the  breeding-ground  of  other  organisms,  part  iciilaily  the  bacteria 


SEPTIC  CASES.  457 

of  putrefaction.  The  altered  portions  of  pulp  tissue  are  decomposed 
into  products  of  progressively  simpler  chemical  composition,  until  all 
of  the  albuminous  substances  have  been  transformed  :  first  peptones  are 
formed,  further  decomposition  produces  ptomains,  next  such  bases  as 
leucin,  tyrosin,  and  the  amines,  together  with  fatty  acids ;  ^  finally  the 
end  products  are  hydrogen  sulfid,  ammonia,  carbon  dioxid,  and  water 
(see  Fig.  398).  "Fermentation  and  putrefaction  can  only  occur  where  the 
fungi  concerned  live,  and  the  extent  of  decomposition  is  conditioned  by  the 
number  of  fungi''  (Ziegler). 

As  there  are  several  distinct  types  of  decomposition,  so  is  there  a  cor- 
responding number  of  varieties  of  organisms.  The  septic  cases  may  be 
divided  into  two  classes  :  First :  Those  in  which  septic  invasion  has  not 
passed  beyond  the  apical  foramen  and  given  evidence  of  pericemental 
irritation  or  inflammation,  these  tissues  being  threatened  though  not 
invaded.  Second :  Those  in  which  the  pericementum  has  become  the 
seat  of  septic  invasion.  This  latter  class  is  subdivided  according  to  the 
nature  and  extent  of  the  septic  processes  :  the  first  subdivision  comprises 
cases  of  acute  pericementitis  non-purulent ;  the  second,  of  chronic  peri- 
cementitis without  evident  pus  formation  ;  the  third,  of  purulent  peri- 
cementitis, which  may  be  either  acute  or  chronic. 

1.  In  the  first  of  the  first  class  of  these  cases — those  in  which  the 
suppurative  process  has  invaded  the  pulp  to  near  its  end — the  necrotic 
portions  of  the  pulp  are  undergoing  putrefactive  decomposition.  To- 
ward the  end  of  the  process,  when  the  apical  portion  of  the  pulp  is 
invaded,  it  is  not  uncommon  to  find  evidences  of  pericemental  irritation ; 
this  frequently  ceases  spontaneously,  as  though  the  irritation  liad  caused 
the  formation  of  a  barrier  between  the  tissues  of  the  apical  region 
and  the  suppurating  pulp.  An  increasing  discoloration  of  the  dentin 
shows  the  contents  of  the  dentinal  tubules  to  be  also  undergoing  de- 
composition. It  is  necessary  to  remove  this  mass,  destroying  the 
products,  the  causes,  and  the  soil  of  decomposition  :  this  without  carry- 
ing infection  to  the  vital  tissues  beyond  the  apex.  When  the  odor  of 
hydrogen  sulfid  may  be  detected,  it  is  evidence  that  the  ultimate  de- 
composition of  albuminous  matter  is  in  progress.  As  it  is  quite  prob- 
able and  an  imminent  danger  that  organisms  might,  upon  a  broach 
injudiciously  employed,  be  carried  from  the  body  of  the  putrescent 
mass  to  the  apex  of  the  root,  it  is  the  part  of  wisdom  and  prudence  to 
destroy  the  organisms  as  a  primary  measure.  There  is  no  quicker  or 
effective  means  of  destroying  H2S,  and  probably  the  causes  leading  to 
its  production,  than  applications  of  iodin.  The  reaction  involved  in 
the   decomposition    of  HgS  by  iodin   was   pointed  out  by  Dr.  W.   F. 

'  Ziegler,  GeTieral  Pathology,  1895,  p.  437. 


458  THE  TREATMENT  AND   FILLINC'    OF  ROOT  CANALS. 

Litcli:'  "  111  iKissiiii;  a  stream  of"  liydi-oircii  siiltid  lliiniiMli  tincture  oi' 
iodin,  the  latter  eleineiit  seizes  upon  tlie  liy(lr()ti;eii,  foniiinii-  liydriodic 
acid,  wliieli  veinaiiis  in  solution,  the  sulfur  falls  as  a  preeipitate  ;  the 
solution  is  deeol(»rized."  Any  excess  of  iodin  which  remains  may  be 
rcadilv  removed  by  an  application  of  ammonia  water,  a  solution  of 
ammonium  iodid  bcintj  formed  which  may  be  readily  washed  away. 

A  penetrating  antiseptic  is  now  indicated,  to  sterilize  to  as  great  a 
depth  as  practicable.  A  5  per  cent,  solution  of  formalin  fulfils  this 
indication.  It  is  permitted  to  act  for  some  time.  The  contents  of  the 
canal  are  scraped  away,  never  pushing  the  broach  by  which  the  scraping 
is  done,  for  fear  of  carrying  organisms  deeper  into  the  canal. 

As  stated,  se])tic  canals  contain  certain  fatty  bodies  and  derivatives 
of  albumin,  together  with  more  or  less  partially  disorganized  ])id})  tissue 
and  a  mixed  bacterial  infection.  Examining  the  list  of  therapeutic 
agents  it  is  seen  that  one  of  them,  sodium  dioxid,  possesses  properties 
capable  of  neutralizing  each  of  the  offending  elements.  This  nuiterial 
may  be  employed  either  in  the  solid  form  or  in  solution.  Solutions  of 
sodium  dioxid  must  be  made  with  great  care  to  prevent  eseai)e  of  the 
oxvgen.  A  tumbler  of  distilled  water  is  set  in  a  vessel  containing  ice- 
Avater;  into  the  distilled  water  the  sodium  dioxid  is  dusted  very  slowly 
in  small  amounts.  Each  addition  is  attended  by  the  evolution  of  heat.^ 
The  sodium  dioxid  is  added  to  the  point  of  saturation,  and  reduced  to 
the  desired  percentage  strength  by  additions  t)f  distilled  water.^ 

A  drop  of  the  saturated  solution  is  placed  upon  a  wisp  of  asbestos 
fiber  (as  it  destroys  cotton  fiber)  and  is  carried  into  the  canal ;  in  a  few 
moments  the  cavity  may  be  syringed,  and  a  deeper  application  of  the 
dioxid  solution  made — this  time  of  50  per  cent,  solution.  Each  time 
the  asbestos  is  removed  it  is  seen  that  the  discolored  dentin  surrounding 
the  canal  becomes  whiter;  the  discoloring  matter  in  the  tubules  has  been 
destroyed. 

When  a  broach  may  be  passed  freely  to  the  apex  of  the  root,  and 
the  solution  comes  away  clear  from  the  root,  sterilization  is  presumably 
complete.  A  10  per  cent,  solution  of  sulfuric  acid  is  pumped  into  the 
canals  by  means  of  iridium  broaches  ;  this  neutralizes  any  free  alkali 
which  may  be  present.  The  canal  or  canals  are  next  washed  out  with 
hot  distilled  water,  dried  with  cotton,  filled  with  alcohol,  and  \vell  dried 
by  blasts  of  warm  air. 

Many   operators    immediately    and    permanently    fill    such    canals ; 

»  Dental  Cosmos,  1882. 

^  Dr.  \Vm.  Trueman  advises  that  the  soldered  lid  of  the  can  containing  tlie  oxid  be 
perforated  as  a  pepper  caster,  and  the  sodium  dioxid  sliaken  int(i  the  distilled  water 
through  the  perforations. 

*E.  C.  Kirk,  Denial  Cosmos,  vol.  xxxv.  p.  lyo;  F.  T.  Van  Woert,  ibid.,  vol.  xxxvi. 
p.  499. 


CASES  IN   WHICH  PERICEMENTITIS  IS  PRESENT.  459 

however,  as  there  is  the  possibility  that  sterilization  may  not  be  abso- 
lute, it  is  the  usual  practice  to  fill  the  canals  tentatively  yet  perfectly. 
Salol  and  a  metallic  point  make  an  excellent  canal  filling  in  such 
cases.  When  the  canals  and  dentinal  walls  are  dried  by  means  of  the 
alcohol  and  warm  blast  they  are  filled  wdth  salol  made  very  fluid,  and 
the  metallic  point  thrust  into  the  canal  containing  it.  Some  slight 
pericemental  disturbance  may  follow,  but  quickly  subsides  under  the 
influence  of  a  counter-irritant  applied  to  the  gum  over  the  root  (tr. 
iodin.,  tr.  aconit.  et  chloroform,  da.  pars  ceq.  The  crown  cavity  is  sealed 
with  sticky  temporary  stopping  for  a  few  days,  when  if  the  condition 
of  the  pericementum  is  found  normal,  the  salol  filling  is  removed  (if 
the  operator  desires)  by  heating  a  pair  of  tweezers  and  grasping  the 
protruding  end  of  the  metal  cone.  It  is  the  general  practice  to  then 
fill  the  canal  with  oxychlorid  or  gutta-percha. 

Should  the  case  present  evidences  of  profound  change  in  the  contents 
of  the  tubules,  i.  e.  much  discoloration,  the  50  per  cent,  solution  of 
sodium  dioxid  may  be  sealed  in  the  canal  for  a  day ;  the  next  day  the 
canals  are  syringed  freely  with  an  acid  solution  of  hydrogen  dioxid. 
Dr.  Kirk  advises  that  the  dentin  be  saturated  with  the  sodium  dioxid 
solution,  then  upon  the  addition  of  hydrochloric  acid,  hydrogen  dioxid 
is  formed  wherever  the  sodium  has  penetrated,  and  drives  out  the  soapy 
matters  formed  by  the  action  of  sodium  hydroxid  upon  the  products  of 
decomposition. 

Preliminary  to  filling  the  canals  it  is  the  usual  practice  to  fill  them 
for  a  few  minutes  with  an  antiseptic,  which  will  exercise  an  influence 
over  a  considerable  period  of  time.  Of  all  antiseptics,  oil  of  cinnamon 
gives  evidence  of  the  most  prolonged  presence  when  so  placed.  The  use 
of  cinnamon  oil  in  the  pulp  chambers  of  front  teeth  is,  however,  objec- 
tionable, owing  to  the  tendency  of  the  oil  to  discolor  the  dentin  structure. 
It  is  therefore  preferable  in  these  cases  to  use  a  dressing  of  dilute  for- 
malin (2  per  cent,  solution),  w-hich  by  its  difiusibility  thoroughly  penetrates 
the  tubuli,  sterilizing  their  contents. 

Cases  in  which  Pericementitis  is  Present. 

The  next  class  for  consideration  includes  the  cases  in  which  the 
tissues  of  the  apical  region  are  invaded.  The  first  evidence  of  such 
invasion  is  tenderness  of  the  tooth  upon  pressure.  The  cause  of  this  is, 
no  doubt,  the  inflammatory  reaction  of  these  tissues  consequent  upon  con- 
tact and  absorption  of  the  waste  products  of  organisms  which  are 
developing  in  the  pulp  canal.  In  the  milder  cases  the  tooth  is  sore  to 
the  touch,  is  slightly  loose  and  extruded,  and  the  gum  over  the  aifected 
root  is  redder  than  normal.  Here,  as  in  all  grades  of  this  disturbance, 
the  aim  is  to  get  rid,  first,  of  the  causes  of  the  inflammation  ;  second,  when 


460  THE   TREATMENT  AM>    FIIJJXC    OF  ROOT  CANALS. 

iuross;iry  to  treat  the  iiiflaimnatioii  itxll'.  1  ii  ctVcctiiiu  an  cut  I'aiicc  into  the 
canals  of  such  tcrlli — antl  of  cour.-f  they  ^Imnld  ))<•  opened  and  cleansed 
as  quickly  and  as  tiioroui;iily  as  ])()ssil)lc — "  tiic  tooth  should  receive 
lateral  support  against  the  pressure  of  the  burs  used  in  excavating  ;  if 
the  cavity  be  approxinial  the  tip  of  a  finger  is  placed  against  the  face 
of  the  tooth  on  the  opposite  side  to  the  bur.  Should  the  ilirection 
of  entrance  be  in  a  perj)cndicular  line  a  ligature  of  linen  twine  having 
long  ends  may  be  tied  tightly  about  the  neck  of  the  tooth,  and  traction 
exerted  as  a  counter-pressure."  ' 

If  the  conditions  ])ennit,  the  cleansing  and  sterilizing  are  to  be  well 
done  at  once.  Shoukl  the  tooth  be  too  tender  to  j)ennit  the  usual 
manipulations,  the  gross  mass  is  removed  by  treatment  with  sodium 
dioxid  solution  or  by  syringing  with  meditrina  and  stirring  with 
broaches ;  then  a  pellet  of  cotton  saturated  with  lysol,  a  strongly  alka- 
line and  penetrating  cresol,  is  placed  against  the  putrescent  mass  ;  the 
gum  is  painted  with  iodin  at  a  little  distance  from  the  site  of  the  inflam- 
mation. When  quiet  is  secured,  the  cleansing  and  sterilization  of  the 
canals  should  be  thoroughly  done  ;  and  a  dressing  of  a  sedative  anti- 
septic introduced.  Campho-phenique  or  cinnamon  oil  answers  well  in 
this  ])articular. 

In  more  pronounced  cases  the  tenderness,  extrusion,  and  looseness 
of  the  tooth  are  more  marked  ;  in  case  the  tooth  should  contain  a  filling 
beneath  which  a  l>nlp  has  died — and  this  is  a  common  history  of  such 
cases — the  release  of  the  imprisoned  mephitic  gases  is  imperative.  Ex- 
ercising counter-pressure,  a  very  sharp  and  small  spear-pointed  drill  is 
passed  through  the  wall  into  the  pulp  chamber  ;  it  may  bo  necessary  in 
cases  of  extreme  soreness  to  effect  this  entrance  at  tiie  neck  of  the  tooth 
as  the  shortest  path.  After  a  few  minutes  the  opening  is  syringed  out 
with  meditrina,  and  a  blister  is  applied  over  the  gum  at  a  distance  from 
the  tooth,  about  two  teeth  posterior  to  it.  Several  coats  of  saturated 
alcoholic  solution  of  iodin  applied  in  succession  as  rapidly  as  the 
preceding  application  has  dried  and  until  the  surface  is  coated  with 
a  bronze-like  layer  of  iodin  will  produce  satisfactory  counter-irrita- 
tion. An  area  of  about  1|  to  2  centimeters  diameter  may  be  thus 
covered.  The  patient  is  directed  to  immediately  take  a  hot  mus- 
tard foot-l>ath,  and  to  use  frequently  a  8  per  cent,  solution  of  pyro- 
zone  or  other  strong  antiseptic  solution  as  a  mouth-wash.  W'lien 
the  tooth  is  much  extruded  and  is  kept  irritated  by  striking  upon  the 
occluding  tooth,  it  is  advisable  to  place  a  cap  over  the  tooth  ])osterior 
to  the  one  afiected.  A  cap  may  be  readily  made  in  a  few  minutes,  by 
taking  an  impression  in  moldine  or  in  plaster  of  the  tooth  to  be  capped, 
pouring  a  small  die  of  fusible  metal ;  drive  this  into  a  block  of  soft 
'  J.  Foster  Flagg's  Lectures. 


CASUS  IN   WHICH  PERICEMENTITIS  IS  PRESENT.  461 

lead,  and  then  swage  a  piece  of  silver  or  German  silver,  No.  26,  to  fit 
the  die.  This  cap,  covering  the  occlusal  face  and  about  half  the  walls 
of  the  tooth,  is  attached  by  means  of  zinc  phosphate,  thus  securing 
surgical  rest  for  the  affected  tooth.  It  was  at  one  time  a  general  prac- 
tice to  permit  the  vent  hole  drilled  at  the  neck  of  a  tooth  to  remain 
open  for  the  escape  of  the  gases  of  decomposition,  consequently  the 
eases  were  in  a  constant  state  of  sepsis.  The  practice  is  obsolete  and 
is  to  be  unqualifiedly  condemned. 

In  cases  where  the  inflammatory  action  runs  high,  the  tooth  is  ex- 
tremely tender,  much  extruded,  and  loose,  the  gum  over  the  tooth  be- 
comes livid,  the  pulse  increases,  there  is  some,  and  there  may  be  marked, 
febrile  action,  the  tongue  is  coated  and  the  breath  offensive.  Energetic 
measures  are  necessary  to  avert  necrotic  action  in  the  apical  tissues. 
In  this,  as  indeed  in  all  cases  without  exception,  the  promptness  and 
thoroughness  of  relief  depends  primarily  upon  the  thoroughness  with 
which  the  exciting  cause  of  the  inflammation  is  removed,  i.  e.  the  septic 
contents  of  the  pulp  chamber.  In  any  case  where  direct  access  may  be 
had  to  the  canals,  and  this  is  very  frequently  the  case,  every  effort  short 
of  that  producing  great  suffering  to  the  patient  should  be  employed  to 
wash  away  and  broach  away  the  putrescent  material,  using,  where  ne- 
cessary, sulfuric  acid  to  enter  the  canals,  powerful  antiseptics  always 
preceding  the  broach.  Lysol  is  an  excellent  medicament  in  this  con- 
nection, and  campho-phenique  another.  The  canal  is  syringed  freely 
and  repeatedly  with  3  per  cent,  pyrozone,  which  should  also  be  used  as 
an  antiseptic  mouth-wash.  Local  bloodletting,  as  advised  by  Dr.  G.  V. 
Black,^  is  frequently  an  effective  means  for  securing  relief.  Make  a 
deep  cut  in  the  gum,  clear  to  the  process,  the  incision  to  be  about  one- 
quarter  inch  from  the  margin  of  the  gum  and  encircling  the  neck  of  the 
tooth  ;  this  will  tend  toward  unloading  the  engorged  vessels  of  the  apical 
region.  Dry  cups  over  the  face  and  to  the  neck,  and  always  hot  mus- 
tard foot-baths,  are  valuable  adjuncts. 

Should  the  inflammatory  disturbance  run  high,  and  a  full,  bounding 
pulse,  coated  tongue,  marked  fever,  constipation,  headache,  and  other 
febrile  symptoms  appear,  attempts  should  still  be  made  to  abort  the 
inflammatory  action.  After  as  thorough  a  cleansing  of  canals  and  anti- 
septic washing  as  possible  under  the  circumstances,  local  bloodletting 
as  described  and  advised  by  Dr.  Litch  ^  is  efficient,  by  means  of  Swedish 
leeches,  washing  the  gum,  touching  it  with  sugar,  then  applying  the 
leech,  which  should  be  first  placed  in  a  test-tube,  the  mouth  of  the  tube 
then  being  placed  over  the  gum  ;  when  the  leech  is  gorged,  it  drops  back 
into  the  tube.     The  mouth  is  then  rinsed  with  warm  water,  to  continue 

^  American  System  of  Dentistry,  vol.  i.  p,  927. 
2  Ibid.,  vol.  i.  p.  928. 


462  TIIK   TRKATMF.ST  A.\D    FILLIMl    OF   fx'ooT  CAXALS. 

the  bleeding,  (^iiiniii  in  doses  never  less  tlian  ijr.  vj  is  given  in  the  hope 
of  limiting  the  exudation  int<i  the  inflamed  area.  As  one  of  the  best  and 
most  effeetive  means  of  derivation  is  the  indnetion  of  watery  alvine  dis- 
charges, the  patient  may  be  direeted  to  take  a  .saline  cathartic  or  a  rectal 
injection  of  half  an  ounce  of  pure  glycerin.  If  the  pulse  remain  full  and 
hounding,  and  headache  persist,  tr.  aconiti  or  tr.  veratri  viridis  is  to 
be  used  as  an  arterial  sedative,  gtt.  j  of  the  tr.  aconiti  rad.,  or  gtt.  ij  of 
the  tr.  veratri  viridis,  repeated  every  hour,  until  the  pulse  slows  and 
lessens  in  volume  and  tension.  At  bedtime,  if  the  inflammation  be  not 
markedly  lessened,  a  sedative  diaphoretic  is  administered,  Dover's  pow- 
der in  full  dose,  gr.  x,  given  in  hot  lemonade  ;  while  the  patient  is  drink- 
ing the  latter  he  or  she  is  to  be  well  wrapped  in  hot  blankets  and  the 
ivvt  and  legs  immersed  in  a  hot  mustard  foot-bath.  The  following 
morning  a  saline  cathartic — magnesiie  sulph.  sss — is  given  in  a  goblet 
of  water.  These  directions  (substantially  those  given  by  Dr.  Litch, 
ibid.),  may  be  followed  with  gratifying  results  in  many  cases  ;  even 
when  the  inflammation  is  not  aborted,  its  violence  is  almost  invariably 
lessened. 

Should  the  inflammation  remain  at  its  height  for  more  than  twenty- 
four  hours,  it  is  almost  certain  that  pus  has  formed,  and  the  indication 
is  to  give  it  exit.  A  spear-pointed  bistoury  is  thrust  through  the  gum 
over  the  apex  of  the  affected  root  with  such  decided  force  as  to  pene- 
trate the  process  if  possible.  In  the  event  of  not  accomplishing  this 
end,  the  point  of  a  spear-head  drill  revolving  very  rapidly  is  jiassed 
through  the  process  to  the  apical  region.  Although  this  operation  may 
be  performed  very  quickly  it  may  be  necessary  to  administer  nitrous 
oxid  to  quiet  the  patient  and  render  the  drilling  })ainless.  Anesthesia 
may  be  secured  by  means  of  the  injection  of  5  minims  of  a  1  per  cent,  solu- 
tion of  cocain,  to  which  has  been  added  1  to  2  minims  of  a  1  ])er  mille  solu- 
tion of  suprarenal  extract.  Dr.  Black  has  described  a  painless  method  of 
effecting  an  entrance  to  the  apical  region.^  A  napkin  is  placed  about  the 
parts,  the  gum  dried  and  touched  at  the  point  of  election  with  a  drop  of 
95  per  cent,  solution  of  carbolic  acid  (trichloracetic  acid  full  strength 
may  be  used).  The  necrosed  membrane  is  scraped  away  by  means  of  a 
coarsely  serrated  plugger  until  sensation  is  felt,  when  another  drop  of 
acid  is  applied,  and  the  scratching  is  resumed  until  the  bone  is  laid 
bare  ;  a  sharp  chisel  is  then  used  to  open  the  apical  region.  No  blood 
should  be  drawn  during  the  operation  except  at  the  last  step. 

The  case  in  its  present  stage  belongs  to  and  is  described  in  the  suc- 
ceeding chapter,  upon  Alveolar  Abscess.  In  any  case  presenting  in 
which  there  is  reason  to  believe  the  patient  is  the  victim  of  syphilis — 
and  alveolar  periostitis  is  an  occasional  accompaniment  of  tertiary  syphi- 
'  American  System  of  Dentistnjy  vol.  i.  p.  298. 


TREATMENT  OF  CHRONIC  PERICEMENTITIS.  463 

lis  ^ — the  use  of  large  doses  of  potassium  iodid  is  imperatively  indicated. 
Unless  decided  measures  are  taken  to  abort  such  cases — and  the  usual 
antiphlogistic  measures  are  of  little  avail — dangerous  involvement  of 
the  general  periosteum  may  occur,  leading  to  necrosis.  Not  less  than 
gr.  vj  doses  of  potassium  iodid  are  to  be  administered  every  three  hours. 
Should  there  be  evidence  of  detachment  of  the  periosteum,  indicated  by 
boggy  swelling,  a  bistoury  is  to  be  passed  boldly  to  the  bone,  making  a 
large  and  free  incision. 

Treatment  op  Ohbonic  Pbbicementitis. 

The  most  usual  form  of  chronic  apical  pericementitis  is  that  associ- 
ated with  pus  formation.  It  will  be  discussed  in  the  succeeding  chapter 
under  the  head  of  Chronic  Apical  Abscess. 

A  not  inconsiderable  number  of  cases  may  be  seen  in  which  pus 
formation  is  not  evident  and  yet  a  chronic  inflammation  is  present  in 
the  tissues  of  the  apical  region.  If  the  pulp  chamber  be  open  the 
cause  is  evident,  and  its  treatment  has  been  described.  A  not  inconsid- 
erable number  of  cases  are  due  to  mal-occlusion.  This  point  is  to  be 
carefully  observed,  for  it  frequently  affects  teeth  containing  vital  pulps 
and  free  "from  caries.  The  tooth  is  slightly  loose  and  sore  to  pressure. 
Examination  reveals  abnormal  occlusion,  either  too  severe  or  in  the 
wrong  direction.  Should  the  tooth  contain  a  filling,  it  usually  gives  a 
normal  response  to  applications  of  heat  and  cold  ;  examining  the  filling 
a  spot  is  seen  marking  excessive  occlusion  ;  in  both  cases  grinding  oflP 
the  redundant  tooth  structure  or  filling  and  applying  a  counter-irritant 
over  the  apex  subdues  the  inflammation.  Its  exciting  cause  being 
removed,  it  subsides. 

A  class  of  cases  is  occasionally  met  with  in  which  there  is  evidence 
of  sluggish  and  persistent  inflammation  about  the  apices  of  pulpless 
teeth  which  have  been  filled ;  acute  inflammatory  disturbance  of  a 
severe  grade  occurs  but  seldom.  The  most  common  cause  of  this  con- 
tinued inflammation  is  probably  the  decomposition  of  a  minute  filament 
of  pulp  tissue  which  has  not  been  removed  from  a  canal  ;  or,  again, 
well-cleansed  canals  which  have  not  been  filled  to  the  apex.  Such 
cases  are  those  of  mild  sepsis  :  perfect  restoration  to  health  is  only  pos- 
sible by  re-cleansing,  sterilizing  and  perfectly  filling  the  canals.  These 
teeth  are  always  more  or  less  hypersensitive  even  though  it  be  unnoticed, 
and  therefore  are  not  of  a  full  measure  of  service  until  cured. 

Other  cases  in  which  there  is  reasonable  assurance  of  perfect  steril- 
ization and  complete  filling  exhibit  vascular  sluggishness  over  the  apex 
of  the  root.     Continued  and  repeated  massage  is  beneficial,^  the  disorder 

^  See  case — Heath,  Injuries  and  Diseases  of  the  Jaws,  3d  edition.  ' 

^  Dr.  W.  F.  Eehfuss,  International  Dental  Journal,  vol.  xi.  p.  581. 


464  THE  TREATMEST  AND  FILLING   OF  ROOT  CAXALS. 

being  apiKircntly  due  to  paralysis  ot"  vessel  walls  and  not  to  se|)tie 
causes.  The  tonus  of  the  vessels  may  he  improved  liy  ap|)lieation  of 
the  fjalvauic  current.  This  ])rineiple  lias  wide  ap])lieation  in  licneral 
medicine  and  surp^ery. 

It  is  to  be  remembered  that  when  the  tissues  aixtut  the  apex  of  a 
root  have  been  irritated,  it  may  be  for  months,  by  the  products  of  a 
deeomj»osin2:  i)nlp,  a  series  of  degenerative  changes  may  iiave  occurred 
in  them  wliieli  recpiire  some  time  to  remedy.  Sterilization  should  be 
prolonged,  and  too  hasty  a  stopping  of  the  canal  be  avoided.  In  such 
cases,  after  each  periodical  treatment  the  canal  should  be  dressed  with 
some  stimulant  antiseptic  :  cann)ho-pheni([Ue  ;  oil  of  cinnamon,  or  the 
admirable  1,  2,  3  mixture  of  Dr.   Klack  : 

Oil  of  cinnamon,  1  part ; 

C'arl)olic  acid,  2  parts; 

Oil  of  wintergrecn,  3      " 

Repeated  applications  of  tr.  aconit.  et  iodin.  arc  to  be  made  to 
the  gums. 

A  source  of  chronic  apical  pericementitis — frequently  not  detected 
until  abscess  has  formed  and  discharged,  it  may  be,  at  a  distant  point — 
is  found  in  the  death  of  a  l)ulp  from  throndnis  or  jugulation.  At  some 
period  the  tooth  has  received  a  blow,  or,  it  nuiy  be,  has  been  moved 
too  rapidly  by  a  regulating  appliance,  or  idiopathic  puljiitis  has  occurred. 
Years  afterward,  a  chance  examination  may  reveal  a  deeper  color  of 
the  gum  overlying  the  tooth  than  over  the  others  ;  by  reflected  light  it 
shows  an  opacity  or  discoloration  of  the  body  of  the  tooth.  It  may  be 
slightly  sore  to  percussion,  which  elicits  a  dull  sound.  "■  Dead  pulp"  is 
diagnosticated ;  the  tooth  is  opened  under  extraordinary  antiseptic  pre- 
cautions and  cleansed  freely  with  sodium  dioxid — the  ideal  material  in 
this  instance — dried,  and  filled  at  least  tentatively  with  salol. 

Another  class  of  cases  in  which  a  similar  condition  of  the  pulp  is 
found  consists  of  those  in  which  a  pulj)  has  died  from  repeated  thermal 
shock  received  through  a  metallic  filling  jdaccd  in  too  close  proximity 
to  it.  Although  constructive  action  resulting  in  secondary  deposits  is 
the  usual  consequence  of  such  irritation,  profound  degenerative  changes 
in  the  tissue  of  the  pulp  frequently  occur  at  later  periods.  The  treat- 
ment is  the  same  as  in  the  preceding  case. 

Unless  the  degree  of  antisepsis  stated  be  employed  in  cleansing  the 
canals  of  such  cases,  an  annoying  and  it  may  be  an  obstinate  perice- 
mentitis is  lighted  up  which  is  difficult  to  conquer. 

A  word  of  caution  should  be  spoken  in  regard  to  the  importance  of 
the  removal  of  inflanmiatory  troubles,  particularly  the  subacute  forms, 
which  affect  the  apical  pericementum.     It  is  supposed  and  with  good 


TREATMENT  OF  CHRONIC  PERICEMENTITIS.  465 

reason  that  not  only  may  tumor  formations  have  their  beginning  in 
chronic  inflammations ;  various  reflex  disturbances  of  sensation  and  of 
special  sense  may  be  traced  to  such  sources ;  but  any  inflammation 
having  such  an  anatomical  situation  is  a  smouldering  fire  which  may 
under  certain  systemic  conditions  become  a  pathological  conflagration. 

Finally,  the  injudicious  use  of  arsenical  preparations  in  pulp  devitali- 
zation may  result  in  chronic  irritation  to  a  part  of  or  the  entire  peridental 
membrane,  the  irritative  action  being  prolonged  indefinitely  after  extirpa- 
tion of  the  pulp  and  successful  filling  of  its  canal.  This  condition  is  due 
to  the  diffusion  of  the  arsenic  through  the  dentinal  structure  and  cemen- 
tum,  and  is  a  result  which  is  more  easily  avoided  than  cured.  Where 
the  arsenical  application  has  been  unduly  prolonged  by  circumstances 
beyond  the  control  of  the  operator,  and  the  possibility  of  undue  penetra- 
tion of  the  poison  is  suspected,  the  application  of  silver  nitrate  to  the 
canal  walls  will  render  the  arsenic  inert  by  combining  with  it  to  form  the 
insoluble  silver  arsenite. 

The  possibility  of  disturbance  to  the  peridental  membrane  which  may 
be  induced  by  arsenical  pulp  applications  should  limit  its  use  only  to  such 
cases  where  surgical  extirpation  of  the  pulp  under  local  anesthesia  is 
deemed  to  be  practically  impossible. 


30 


CHAPTER    XVIII. 

DENTO-ALVEOLAR  ABSCESS. 

By  Heney  H.  Burchard,  M.  D.,  D.  D.  S. 


Definition. — In  describing  the  septic  inflammation  affecting  the 
tissues  of  the  apical  region  in  the  previous  chapter,  it  was  stated  that  a 
common  result  of  the  inflammatory  action  was  cellular  necrosis  and  pus 
formation  ;  this  condition  is  known  as  alveolar  abscess  or  dento-aheolar 
abscess. 

Although  alveolar  abscess  affecting  some  other  portion  of  the  peri- 
cementum may  and  does  occur  without  death  of  the  pulp,^  septic  infec- 
tion and  bacterial  invasion  of  the  tissues  of  the  periapical  region  from 
infected  pulp  canals  is  the  most  common  source  and  cause  of  the  affec- 
tion. The  term  as  technically  applied  refers  to  septic  apical  pericemen- 
titis. 

Causes  of  Dento-alveolar  Abscess. 

The  exciting-  causes  of  the  disease  process  will  be  found  in  the  pyo- 
genic cocci  and  probably  other  pyogenic  organisms  which  inhabit  and 
develop  in  the  deepest  portions  of  the  putrescent  pulp,  finding  entrance 
to  the  periapical  tissues  through  the  apical  foramen  of  the  tooth.  Dr. 
Schreier  of  Vienna  found  diplococcus  pneumonia  to  be  the  excitant  of 
inflammation  in  seventeen  out  of  twenty  cases  of  dental  periostitis 
examined  by  him.^  The  ptomains  and  other  waste  products  formed  as 
the  result  of  the  life  processes  of  these  organisms  cause  poisoning  and 
debility  of  the  cellular  elements  of  the  part.  Even  granting  that  the 
organisms  are  present  as  the  exciting  cause,  there  is  another  factor 
involved  which  determines  to  a  great  extent  the  occurrence,  time  of 
occurrence,  and  severity  of  the  disease,  /.  e.  the  predisposing  causes — 
including  under  this  head  the  condition  of  the  tissues  which  favors  or 
deters  the  development  of  the  organisms. 

Predisposing-  Causes. — It  is  uncj[uestionably  true  that  different  in- 
dividuals will  exhibit  in  their  tissues  marked  differences  in  the  degree 

^  Cases  reported  in  Proc.  Academy  of  Stomatology  of  Philadelphia,  1895. 
'''  Oesterr.-ungarische  Viertelj.  fiix  Zahnheilk.,  April  1893. 

467 


468  DENTO- ALVEOLAR  ABSCESS. 

of  resistance  to  tlu>  ijivasioii  of  disoaso  causes.  It  is  a  well-recognized 
axiom  of  pathology  tliat  one  of  the  most  potent  antiseptics,  if  not  the 
most  potent,  is  the  inherent  resistance  of  healthy  |)rotoplasm  ;  that  is, 
healtiiv  tissues  offer  a  harrier  to  the  development  of  the  exciting  causes 
of  disease,  while  tissues  which  are  debilitated  through  any  of  the  many 
causes  that  affect  them  exhibit  a  diminisiied  resistance  to  the  invasion 
of  the  causes  of  acute  disease.    * 

Prominent  among  the  causes  which  favor  the  development  and  ex- 
tension of  pyogenic  processes  are  the  inherited  conditions  indefinitely 
classified  as  strumous.  The  tissues  of  children  having  a  family  history 
of,  for  example,  syjihilis  or  tuberculosis,  frequently  exhibit  evidences 
of  lack  of  vital  resistance.  They  are  attacked  and  readily  succumb  to 
agencies  which  affect  children  of  healthy  parentage  but  slightly  if  at  all. 
Inflammations  about  the  teeth  or  of  the  soft  tissues  of  the  month  run  a 
severe  course ;  septic  affections  of  the  pericementum  are  attended  by 
involvement  of  neighboring  lym])hatics  and  by  evidences  of  septic 
intoxication.  These  predispositions  may  persist  throughout  the  life  of 
the  individual ;  as  a  rule,  however,  they  grow  less  pronounced  or  less 
evident  with  age. 

Acquired  cachectic  conditions  of  the  adult  also  form  a  strong  pre- 
disposition to  invasion  of  the  tissues  by  pathogenic  organisms.  It  is  a 
matter  of  frequent  observation  that  tuberculosis  and,  in  a  more  pro- 
noimced  degree,  syphilis  are  constitutional  conditions  which  markedly 
diminish  the  resistance  of  the  tissues.  Inflammatory  disturbances 
which  in  an  individual  free  from  cachexia  would  probably  be  circum- 
scribed, when  they  occur  in  the  cachectic  are  diffuse  and  virulent. 
Local  predisposing  causes  consist  of  faulty  hygiene,  producing  debility 
of  the  tissues,  for  it  is  noted  that  abscess  is  more  likely  to  run  a  virulent 
course  in  unclean  mouths  than  in  those  kept  free  from  fermenting  and 
putrefying  masses ;  this  is  a  general,  though  not  a  universal  truth. 

Pathology  and  Morbid  Anatomy. 

The  pathology  of  septic  pericementitis  has  been  described  in  Chapter 
XVII.  That  of  alveolar  abscess  begins  as  soon  as  there  is  death  of 
cellular  elements  in  the  exudation.  The  exudation  is  liquefied  in  the 
focus  of  the  inflammation  by  the  action  of  ferments  ;  the  leucocytes  are 
invaded  by  and  strive  to  devour  the  pyogenic  cocci  which  are  present — 
the  species  of  warfare  described  by  Metchnikoff;  the  leucocytes 
succumb,  die,  and  form  pus  corpuscles,  which  are  found  to  contain  the 
pvogenic  cocci.  The  cellular  exudate  is  then  broken  down  into  a 
granular  detritus,  which,  with  the  dead  corpuscles  and  peptonized  effu- 
sion, constitutes  pus. 

The   diplococcus  of  pneumonia   is   said  to   be  a   constant   attendant 


PATHOLOGY  AND  MORBID  ANATOMY.  469 

on  alveolar  abscess,  and  this  particular  organism  is  believed  by 
Schreier  to  be  the  usual  excitant  of  the  inflammatory  action  in  these 
cases. 

The  primary  seat  of  the  abscess  is  usually  in  the  pericementum, 
between  its  attachment  to  the  cementum  and  its  attachment  to  the 
alveolus.  From  the  central  cavity  of  softening  the  necrotic  process 
spreads  peripherally ;  cell  by  cell  the  inflammatory  wall  forming  the 
outlines  of  the  abscess  and  the  exudates  are  liquefied  and  the  cavity 
grows  larger.  The  cancellated  bone  about  the  apex  of  the  root  is  in- 
volved and  becomes  the  seat  of  osteomyelitis  and  molecular  necrosis. 
Larger  and  larger  grows  the  volume  of  the  abscess  until  the  periosteum 
covering  the  alveolar  process  is  involved,  softened,  and  raised  from  the 
bone.  The  inflammatory  action  precedes  the  advance  of  the  pus  along 
the  line  of  least  resistance ;  and  if  it  run  high  the  periosteum  may  be 
softened  over  quite  an  extensive  area  and  raised  from  the  bone  by  the 
exudation  beneath  it.  The  pus  penetrating  the  periosteum,  the  soft  tis- 
sues are  involved  and  softened,  when  the  pus  breaks  through  the  mu- 
cous membrane,  discharging  usually  by  the  shortest  route  from  the 
abscess  to  the  exterior.  The  progress  of  septic  destruction  is  along  the 
line  of  least  resistance,  and  although  as  a  rule  this  points  upon  the  ex- 
ternal surface  of  the  gum  immediately  above  the  apex  of  the  affected 
root,  it  may  follow  other  directions.  In  some  cases  the  pus  finds  exit 
through  the  pulp  canal  of  the  affected  tooth,  forming  what  is  commonly 
though  incorrectly  known  as  blind  abscess.  This  form  of  abscess  dif- 
fers from  that  with  external  fistula  as  a  result  of  its  mode  of  formation 
rather  than  because  of  any  essential  difference  in  its  pathology.  The 
history  of  an  acute  inflammatory  stage  is  usually  absent  or  it  has  caused 
but  slight  disturbance.  Invasion  of  the  apical  pericementum  by  bac- 
teria has  been  slow  and  superficial  and  the  inflammatory  reaction 
restricted  to  the  tissue  immediately  surrounding  the  apical  foramen; 
the  necrotic  process  has  been  ulcerative  in  character,  molecular  death 
of  the  membrane  taking  place  slowly  until  the  tissue  about  the  foramen 
is  lost  and  the  denuded  apex  projects  into  a  necrotic  cavity  which  allows 
of  drainage  of  its  contents  through  the  foramen  and  root  canal.  In 
these  cases  the  abscess  cavity  is  usually  comparatively  small,  and  the 
inflammatory  action  is  less  severe  than  when  the  pus  has  a  longer  path 
of  exit  (see  Fig.  449). 

The  pus  may  exhibit  evidences  of  semi-encystment.  Collections 
may  apparently  remain  in  the  tissues  of  the  gum  for  long  periods  with- 
out fistula.  A  case  in  practice  presented  conditions  similar  to  that 
exhibited  in  the  illustration  (Fig.  450) ;  it  had  existed  for  several  years 
about  a  replanted  tooth,  and  responded  ])romptly  to  treatment. 

In  other  cases  the  line  of  tissue  destruction  and  pus  escape  is  along 


470 


DEyrO- ALVEOLAR  ABSCESS. 


the  lu'rii-cnu'iitum,  tlu'  ])us  discharging  at  the  neck  of"  the;  aifocted  tootli. 
Many   <»i'   these    cases   occur 

in  connection    uith   pnlplcss  l<i».. -1)0. 

teeth  which  have  cU»ngatcd, 
or  those  in  which  there  has 
already  heen  h)ss  ol"  peri- 
cementum. 

Abscesses  njion  the  upper 
central  or  lateral  incisors  may 

Fk;.  449. 


Blind  abscess  at  the  root  of  an  upper 
incisor  (Black):  a,  abscess  cavity 
in  bone;  b,  drill  hole  exposing  the 
pulp  chamber  fur  treatment. 


Acute  alveolar  abscess  of  a  lower  incisor  with  pus  cav- 
ity between  the  bone  and  the  periosteum  (Black): 
a,  pus  cavity  in  the  bone  ;  6,  pus  between  the  peri- 
osteum and  bone;  c,  lip:  d,  tooth  ;  e,  tongue. 


perforate  the  nasal  floor  (see  Fig.  451).    After  a  period  of  marked  perice- 


FiG.  452. 


Alveolar  abscess  at  the  root  of 
a  superior  incisor  discharging 
into  the  nose  (Black);  a,  large 
abscess  cavity  in  the  bone;  b, 
mouth  of  fistula  on  the  floor  of 
nostril;  c,  lip;  (/.tooth. 


Alveolar  abscess  at  the  root  of  an  upper 
molar  discharging  into  the  antrum  of 
Highmore  (Black):  a,  abscess  cavity  in 
the  bone ;  b,  mouth  of  fistula  on  the 
floor  of  the  antrum ;  c,  pus  in  the  antral 
cavity. 


mental  disturbance,  the  inflammatory  action  running  high,  causing  pain 
and  swelling  of  the  nostril  of  the  same  side,  the  symptoms  may  suddenly 


PATHOLOGY  AND  MORBID  ANATOMY. 


471 


abate  without  any  evident  signs  of  pus  having  been  discharged.  Soon 
after  a  purulent  discharge  may  be  noted  from  the  nostril,  leading  to  the 
belief  that  purulent  nasal  catarrh  (ozena)  is  present ;  many  of  these  cases 
are  diagnosed  and  treated  as  ozena.  In  injection  of  the  pulpless  incisor, 
particularly  with  pyrozone,  the  pus  and  fluid  are  seen  to  emerge  from  the 
nostril,  exhibiting  the  true  source  of  the  pus.  Abscesses  upon  upper 
second  bicuspids  and  molars  may  perforate  the  floor  of  the  antrum 
(Fig.  452). 

In  the  lower  jaw  the  pus  may  pass  out  of  the  alveolar  process  and 

Fig.  453.  Fig.  454. 


Chronic  alveolar  abscess  at  the  root  of  a  lower  incisor 
with  a  fistula  discharging  on  the  face  under  the 
chin  (Black) :  a,  abscess  cavity  in  the  bone ;  b,  b,  6, 
fistula  following  in  the  periosteum  down  to  the 
lower  margin  of  the  body  of  the  bone  and  dis- 
charging on  the  skin. 


Chronic  alveolar  abscess  of  the  root  of 
a  lower  incisor  with  abscess  cavity 
passing  through  the  body  of  the  bone 
and  discharging  on  the  skin  beneath 
the  chin  (Black) :  a,  very  large  ab- 
scess cavity ;  6,  mouth  of  the  fistula. 


fail  to  perforate  the  overlying  soft  tissues,  pursuing  a  path  which  may 
lead  to  its  exit  upon  the  face  beneath  the  jaw  or  chin  (Fig.  453).  In 
others  the  pus  may  burrow  through  the  body  of  the  bone  and  open 
upon  the  face.     (See  Figs.  454,  455.) 

In  a  case  of  persistent  fistula  opening  upon  the  side  of  the  face  over 
the  body  of  the  lower  maxilla,  there  was  no  evidence  of  inflammatory 
disturbance  in  the  edentulous  gum.  An  exploratory  incision,  made  at 
a  point  indicated  by  a  probe  passed  into  the  sinus,  revealed  the  presence 
of  a  small  root-fragment.  Healing  of  the  fistula  was  spontaneous  upon 
its  removal.  Prof.  M.  H.  Cryer^  records  a  case  of  abscess  opening 
-  Proc.  Academy  of  Stomatology,  1896. 


472 


DENTO-ALVEOLAR  ABSCESS. 


over  the  ImuIv  of  tlu>  lower  maxilla  inun»'(liately  anterior  to  the  frroove 
for  tlie  faeial  art<Ty  (Fig.  456).      A  ilixihle  jtrobe  passed  into  the  tistuhi 


Fig.  455. 


Fio.  1  •")<"•• 


Fistulu  passing  ilown   ihrougli  the  body  of  the 
lower  maxilla  (Black). 


Abscess  with  tortuous  sinus  oi)eninK  ui)ou 
the  face:  A,  tissue  of  cheek;  B,  floor 
of  mouth ;  C,  abscess  tract. 


appeared  to  enter  the  submaxillary  triangle  ;  in  the  absence  of  evident 
dental  cause,  the  case  had  been  diagnosticated  and  treated  as  abscess  of 
the  submaxillary  gland.  The  direction  taken  by  the  probe  gave  no 
iudieation  of  a  tooth  being  involved.  The  usual  theraj>eutie  measures 
applied  to  a  submaxillary  abscess  proving  unavailing,  a  serial  examina- 
tion, one  of  many,  of  the  teeth  of  that  side  was  made.  In  one  tooth,  the 
second  molar,  was  a  large  amalgam  filling.  The  pulp  responded,  though 
feebly,  to  the  usual  tests  for  vitality  ;  upon  entrance  to  the  tooth  the 
anterior  portion  of  the  pulp  was  found  partially  vital,  the  posterior 
portion  dead  and  decomposing.  The  pulp  was  removed  ;  antiseptics 
were  pumped  through  the  posterior  root,  found  exit  at  the  fistula,  and 
the  causal  relation  of  the  putrescent  pulp  and  the  abscess  was  shown 
by  a  prompt  disappearance  of  the  disease. 

In  one  case  of  abscess  upon  a  lower  third  molar,  the  pus  made  en- 
trance into  the  tissues  about  the  insertion  of  the  internal  pterygoid 
muscle.  Cases  have  been  recorded  in  which  the  ])us  from  abscess  about 
a  low'cr  molar  has  burrowed  through  the  bone  and,  caught  beneath  the 
platysma  myoides  muscle,  it  has  passed  down  the  muscle,  discharging 
from  an  opening  upon  the  neck  or  upon  the  shoulder. 

Abscess  upon  an  upper  molar  may  find  exit  upon  the  face  beneath  the 
malar  bone.  Occasionally  the  duct  of  Steno  may  be  involved  in  the 
abscess  tract  and  salivary  fi.stula  result.  Dr.  Black  states'  that  the 
cases  of  abscess  opening  beneath  the  malar  bone  are  usually  of  the  acute 
variety.  As  a  rule,  however,  cases  which  exhibit  the  pus  exit  at  a  dis- 
tance from  the  seat  of  abscess  are  of  the  chronic  variety. 

The  acute  and  chronic  cases  differ  as  to  their  clinical  histories. 
'  American  System  of  Dentistry,  vol.  i.  p.  940. 


CLINICAL  HISTORY  OF  ACUTE  ALVEOLAR  ABSCESS.         473 

Clinical  History  op  Acute  Alveolar  Abscess. 

Cases  of  apical  pericementitis  in  which  suppuration  occurs  usually 
present  pronounced  evidences  of  severe  inflammatory  action.  The 
throbbing  and  tenderness,  swelling  and  vascular  engorgement  are 
marked ;  there  may  be,  and  usually  is,  more  or  less  febrile  disturb- 
ance with  its  attendant  symptoms  ;  a  full,  bounding  pulse,  more  or  less 
oedema  of  the  surrounding  parts,  the  eye  of  the  aifected  side  may  be 
injected,  etc.,  as  described  in  Chapter  XVII.  under  the  head  of  Acute 
Pericementitis.  In  from  twenty-four  to  forty-eight  hours  a  spot  of 
fluctuation  makes  its  appearance  at  the  summit  of  the  swelling,  the  spot 
becomes  yellow  and  soon  opens,  affording  escape  to  the  abscess  contents. 
As  soon  as  the  pus  has  discharged  the  inflammatory  symptoms  subside 
promptly  and  a  persistent  fistula  remains,  communicating  with  the 
abscess  cavity.  This  comparatively  benign  course  and  termination  is 
not  universal.  It  is  not  at  all  uncommon  to  find  cases  which  at  the 
height  of  the  inflammatory  disturbance  exhibit  evidences  of  septic 
intoxication.  The  septic  substances  formed  by  the  micro-organisms, 
and  in  other  cases  the  organisms  themselves,  gain  entrance  to  the  lymph 
channels  and  are  conveyed  to  the  nearest  lymphatic  glands,  producing 
evidences  of  inflammation  in  them  ;  swelling  and  pain  of  these  glands 
are  very  common.  Cases  are  recorded  in  which  streptococci  appear  to 
have  invaded  the  subcutaneous  tissue,  giving  rise  to  marked  phleg- 
monous inflammation.  Dental  literature  contains  the  records  of  many 
cases  indicating  the  occurrence  of  a  pyemic  condition  consequent  upon 
alveolar  abscess  ;  organisms,  by  gaining  entrance  to  the  blood  channels, 
forming  septic  emboli. 

The  mild  and  less  severe  cases  run  the  average  course  described. 
Many  of  them  by  finding  early  exit  of  the  pus  through  the  pulp  canal 
of  the  affected  root  have  comparatively  light  inflammatory  disturbance  ; 
in  those  cases  in  which  the  evacuation  of  the  pus  is  delayed,  or  in 
which  the  opening  occurs  at  points  distant  from  the  disease  focus,  the 
inflammatory  action  may  be  severe  and  prolonged.  If  the  pus  point 
toward  the  face,  the  skin,  the  subcutaneous  tissues,  and  it  may  be  the  in- 
ternal periosteum  also  exhibit  evidences  of  marked  inflammation  ;  there 
is  much  swelling,  the  skin  may  become  oedematous,  there  is  redness, 
heat,  and  throbbing  pain.  The  external  application  of  poultices  by  the 
patient,  not  at  all  an  uncommon  mode  of  domestic  treatment,  may 
aggravate  the  symptoms,  soften  the  tissues,  and  induce  the  progress  of 
the  pus  to  the  exterior. 

If  in  any  of  the  cases  which  point  in  the  mouth  an  undue  swelling  is 
formed  at  the  height  of  prolonged  inflammatory  action,  pus  beneath  the 
periosteum  is  to  be  feared,  the  pus  stripping  the  softened  membrane 


474  DENTO  ALVEOLAR  ABSCESS. 

from  tlio  Ixtno  over  a  cci'tain  area.  Sliuiild  these  cases  not  olttaiii  (|iiiek 
relief  l)V  ovaeiiatioii  of  tlie  pus,  necrosis  of  the  deniided  hone  may  occur 
(Fie:.  457).  Reattachment  of  the  periosteum  may  take  ])h»ce  even  after 
extensive  separation,  provided  the  pus  be  evacuated  early. 

Fig.  457. 


Necrosis  of  the  buccal  plate  of  the  alveolar  process  from  alveolar  abscess  (Black). 

Cachectic  conditions  exert  a  strong  modifying  influence  upon  the 
course  and  termination  of  alveolar  abscess.  In  strumous  or  dei)i]itated 
persons  the  disease  tends  to  invade  neighboring  structures,  whose  resist- 
ance is  lessened.  This  is  well  illustrated  by  a  case  of  obstinate  maxil- 
lary caries  which  destroyed  the  entire  process  of  one  side,  the  begin- 
ning of  the  disease  being  apical  pericementitis  of  a  lower  bicuspid. 
The  carious  process  became  chronic  soon  after  the  extraction  of  the 
offending  tooth,  and  persisted  until  the  death  of  the  patient  from 
tuberculosis. 

Alveolar  abscess  occurring  in  syphilitic  patients  is  prone  to  involve 
the  deep  structures,  and  more  or  less  necrosis  is  not  an  uncommon 
sequel. 

Clinical  History  of  Chronic  Alveolar  Abscess. 

After  the  subsidence  of  the  symptoms  attendant  upon  the  formation 
and  discharge  of  acute  abscess,  there  is  rarely  a  spontaneous  healing  or 
filling  of  the  ab.scess  cavity  and  tract  with  healthy  granulation  tissue ; 
the  development  of  organisms  in  the  abscess  cavity  and  J>ulp  canal  con- 
tinues and  produces  a  continuance  of  the  suppurative  process,  forming  a 
chronic  abscess. 

In  other  cases  abscess  may  have  developed  without  marked  inflam- 
matory symptoms,  and  yet  a  prolonged  and  obstinate  pus  formation 
occurs  in  the  tissues  of  the  apical  region,  the  pus  finding  exit  through 
the  pulp  eaual,  constituting  what  is  known  as  blind  abscess,  one  of  the 
most  common  of  the  chronic  types. 

Many  of  the  cases  which  open  upon  the  face  are  of  the  chronic 
variety ;   during  the  development  of  the  abscess  and  its  discharge  there 


DIAGNOSIS  AND  PROGNOSIS.  475 

may  be  but  little  evidence  of  inflammatory  action  about  the  affected 
tooth.  This  is  a  common  history  of  cases  which  have  followed  the 
death  of  a  pulp  through  trauma,  years  before  the  discovery  of  the  ab- 
scess. At  some  period  a  tooth  receives  a  severe  blow,  and  for  some 
time  is  the  seat  of  traumatic  pericementitis,  which  subsides  :  it  may  be 
years  after  that  a  fistula  is  established  in  the  mouth  or  upon  the  face, 
without  a  history  of  inflammatory  disturbance. 

As  pointed  out  by  Dr.  Black,  the  direction  of  pus-burrowing  in 
chronic  abscess  is  determined  by  gravity  ;  thus,  if  the  abscess  be  upon 
a  lower  incisor  the  pus  may  burrow,  opening  beneath  the  chin,  as  shown 
in  Figs.  455,  456. 

Sir  John  Tomes  ^  has  called  attention  to  the  tendency  of  pus  to  open 
at  the  angle  of  the  jaw  in  abscesses  affecting  the  lower  third  molars  (see 
cases  noted  above). 

Diagnosis  and  Prognosis. 

Diagnosis. — If  the  pericementum  of  a  pulpless  and  open  tooth  have 
been  the  seat  of  acute  and  marked  apical  inflammation  of  septic  origin 
for  a  longer  period  than  thirty-six  hours  pus  is  almost  invariably 
formed,  and  alveolar  abscess  is  present.  The  diagnostic  symptoms  are 
those  of  acute  pericementitis  desA'ibed  in  Chapter  XVII.  In  case  any 
marked  inflammatory  disturbance  is  found  about  the  maxillary  region 
either  within  or  without  the  mouth,  examination  of  the  teeth  of  the 
affected  side  should  always  be  made,  as  a  large  percentage  of  such  in- 
flammations are  of  dental  origin.  Any  fistula  existing  in  the  maxillary 
regions,  either  within  or  without  the  mouth,  is  to  be  suspected  as  having 
origin  in  a  septic  pericementitis  of  some  tooth. 

A  soft  silver  probe  is  to  be  passed  along  the  tract  to  determine  its 
direction  and,  if  possible,  which  tooth  is  affected.  As  a  rule,  such  a 
tooth  will  itself  exhibit  objective  evidences  of  abscess  and  the  patient 
will  give  a  history  of  subjective  symptoms — those  of  inflammation  of 
pericementum. 

Should  the  tooth  indicated  as  the  affected  one  be  free  from  caries, 
the  thermal  test  is  to  be  applied  to  indicate  the  vitality  or  the  necrosis 
of  the  pulp.  Should  the  tooth  not  respond  to  applications  of  a  pointed 
piece  of  ice,  it  is  possible  it  may  offer  slight  response  to  applications  of 
heat.  It  is  next  examined  by  light  reflected  from  the  ordinary,  or 
better,  the  electric  mouth  mirror,  when,  if  the  pulp  be  dead,  opacity  of 
the  crown  will  be  detected. 

An  abscess  upon  an  upper  incisor  opening  upon  the  nasal  floor  may 
cause  a  discharge  simulating  that  of  ozena ;  an  examination  of  the  nose 
will  reveal  a  teat-like  elevation  upon  the  mucous  membrane  covering 

^  Dental  Surgery. 


476  DENTO-ALVEOLAn   ABSCESS. 

tile  iias;il  ll(Kir  niitl  :iii  iiicisoi-  hciicntli  will  We  Iniiiid  ciirioiis  and  liavini!; 
a  piitri'sccMt  |»iil|),  iir,  ii"  iioii-cariuii-,  a  lilstory  ol"  t  I'aiiinatic  pcriccincn- 
titi-  ami  a  present  opacity. 

It  niav  he  mentioned  liei'<'  in  eonneetion  with  death  of  the  pulp  from 
traumatisMi,  that  eontinned  thread-hitinu:,  hitint;'  very  hard  siihstanees 
sueli  as  pieces  of  ice,  nnts,  etc.,  may  cause  death  oi'  the  origan,  presum- 
ably hy  thromhosis. 

It  is  possible  that  the  direction  taken  hy  the  prohe  which  is  passed 
into  the  fistula  will  ])oint  away  from  the  teeth  present,  passin«2;  into  a 
space  from  which  a  tooth  has  been  extracted.  In  that  event  tiio  ])res- 
enco  of  a  root  frai>inent,  or  ])ieee  of  necrosed  process,  may  be  suspected.' 
Should  the  neighboring  teeth  be  excluded  as  causes  of  an  iuflanunation, 
then;  should  be  no  hesitation  in  making  an  exjiloratory  incision  down 
to  the  end  of  the  probe  which  has  been  i)assed  into  the  fistula.  Cases 
of  dentigerous  cysts  have  been  detected  in  this  manner.  This  condition 
would,  however,  be  suspected  when  there  was  an  absence  of  a  tooth  or 
teeth  from  the  arch,  no  evidence  past  or  present  of  pericementitis  in 
anv  of  the  teeth  of  the  arch,  and  a  cystic  tumor  ])resent  in  the  jaw,  or  it 
mav  be  a  fistula  discharuinti:  upon  the  face  after  a  history  of  maxillary 
periostitis. 

Caries  or  necrosis,  although  in  many  cases  the  result  of  septic  apical 
pericementitis,  may  yet  exhibit  fistuhe  opening  into  the  mouth,  without 
evident  connection  with  the  teeth.  As  a  rule,  cases  of  necrosis  exhibit 
marked  and  wide  evidences  of  chronic  inflammation  of  the  tissues  over- 
Iving  the  dead  or  dying  bone;  there  are  usually  several  fistuhe  dis- 
charging from  it. 

Caries  may  have  but  a  single  fistula  and  simulate  closely  ordinary 
alveolar  abscess.  Diagnosis  is  made  by  passing  an  excavator  through 
the  fistula.  Dead  bone  is  readily  detected  by  touch,  it  has  a  rotten  feel ; 
in  caries  the  instrument  may  be  passed  through  the  dead  bone  in  various 
directions,  and  a  characteristic  dead  sound  is  elicited  by  tapping  upim  it. 
Careful  examination  of  the  teeth  must  be  made  in  all  of  these  cases,  to 
determine  the  condition  of  the  l)ulp  and  pulj)  canals. 

In  passing  an  instrument  through  a  listula  to  the  apex  of  an  ab- 
scessed root,  where  the  disease  action  has  been  of  long  duration,  it  may 
be  found  that  the  apex  of  the  root  is  denuded  of  pericementum,  and 
roughened — that  is,  the  apical  ceraentum  is  necrotic ;  foreign  deposits 
may  be  detected  occupying  portions  of  the  necrotic  area. 

Prognosis. — There  are  several  factors  which  enter  into  the  prognosis 

of  a  tooth  and  its  surroundings  which  are  affected  by  alveolar  abscess. 

First,  the  severity  and  character  of  the  inflammatory  action  and  septic 

invasion.     In  cases  in  which   inflammatory  action  is  localized  and  pre- 

'  See  case — Dr.  Black,  American  System  of  Dentistry,  vol.  i. 


TREATMENT.  477 

senting  none  or  but  little  febrile  disturbance  the  prognosis  is,  as  a  rule, 
favorable  ;  but  a  slight  amount  of  tissue  necrosis  occurs.  Should,  on  the 
other  hand,  the  inflammatory  action  proceed  with  volcanic  violence,  it 
is  possible  that  not  only  may  the  pericementum  suffer  extensively,  but  a 
considerable  portion  of  the  periosteum  over  the  process  may  be  raised 
from  the  bone  during  the  escape  of  the  pus.  Should  this  separation  of 
periosteum  be  maintained  for  more  than  a  fcAV  hours,  the  underlying 
bone  may  suffer  to  the  extent  of  necrosis.  In  case  of  marked  lymphatic 
involvement,  the  neighboring  glands  being  swollen  and  tender,  or  even 
the  skin  over  them  exhibiting  evidences  of  glandular  inflammation 
beneath,  more  or  less  septic  intoxication  will  probably  occur,  and  un- 
less the  focus  of  infection  be  promptly  sterilized,  septicemia  is  to  be 
feared. 

Should  evidences  of  diffuse  cellulitis  occur,  indicating  the  invasion 
of  streptococci  into  the  adjacent  soft  tissues,  it  is  a  danger  signal  of 
threatening  pyemia.^  Heath  -  records  a  case  of  oedema  of  the  glottis  due 
to  the  involvement  of  the  connective  tissues  about  the  glottis  in  the 
oedema  accompanying  a  developing  abscess  upon  a  lower  molar. 

The  prognosis  is  good  in  a  vast  majority  percentage  of  cases,  when 
the  offending  tooth  is  extracted  early  in  the  attack,  or  at  its  height ; 
this  applies  even  with  apparently  very  grave  cases  ;  still  the  prognosis 
as  to  the  retention  of  the  affected  tooth  is  also  very  good,  unless  the 
abscess  run  a  phagedenic  course.  In  many  of  the  cases  of  chronic 
abscess  having  a  distant  discharge  the  abscess  may  be  cured  and  the 
tooth  retained.  Other  cases  obstinately  refuse  to  heal  so  long  as  the 
offending  tooth  is  present. 

Treatment. 

Treatment  of  Acute  Abscess. — The  general  principles  of  treat- 
ment of  alveolar  abscess  are  those  for  the  treatment  of  abscess  in  any 
part ;  the  details  are  of  course  modified  in  accordance  with  the  anatom- 
ical peculiarities  of  the  part  to  be  acted  upon.  These  principles  are 
the  removal  of  all  dead  matter,  together  with  the  active  causes  of  the 
inflammation  and  suppuration,  i.  e.  micro-organisms  and  their  products, 
and  the  induction  of  a  tissue  regeneration  which  shall  serve  to  restore 
parts  lost  through  the  formation  of  the  abscess.  The  therapeutic  means 
applied  are  instrumental  and  medicinal.  The  instrumental  are  the 
instruments  employed  to  gain  access  to  the  focus  of  disease  action,  and 
those  applied  in  the  mechanical  removal  of  dead  parts.  The  medicinal 
measures  include  the  agents  employed  to  wash  out  the  abscess  tract ; 
second,  those  applied  to  destroy  the  active  causes  of  the  suppuration  ; 

^  See  case — Dr.  E.  C.  Kirk,  Proc.  Odonfolngical  Society  of  Pennsylvania,  1892. 
'''  Injuries  and  Diseases  of  the  Jaws,  3d  ed. 


478  DENTO-ALVKOLAR  ABSCESS. 

tliird,  tlic  rcmcdli's  applied  to  iiidiico  new  ti>siio  ^rowtli  ;  and  next,  those 
employed  to  iiiaiiitain  asepsis  until  tiio  healing  process  is  complete. 

The  threat  primary  objects  in  the  manatrement  of  aeute  alveolar 
abscess  are  tour:  First,  it"  the  ease  be  seen  early,  to  use  every  endeavor 
to  abort  the  inflammation,  as  described  in  Chajiter  XVII.  Second, 
to  limit  as  far  as  possible  the  extent  of  ])us  formation,  hence  tissue 
destruction  ;  third,  the  earliest  possible  evacuation  of  the  pus  which  has 
formed  ;  fourth,  the  thorough  sterilization  of  the  abscess  cavity  and  its 
walls. 

Cases  when  seen  may  be  at  any  stage  of  the  disease  process  from  an 
incipient  pericementitis  to  the  establishment  of  a  fistula.  The  treatment 
of  the  early  cases  is  that  of  pericementitis.  In  all  of  these  cases  one  fact 
is  never  to  be  forgotten  :  that  the  pulp  canals  are  the  centres  of  infec- 
tion, and  the  more  quickly  and  thoroughly  they  are  drenched  with 
powerful  antiseptics  the  more  limited  will  be  the  inflammatory  action 
both  in  degree  and  extent,  and  the  more  limited  will  be  the  ])us  forma- 
tion. Attempts  are  therefore  made  to  enter  and  sterilize  cavities  pari 
pasfiu  with  the  antiphlogistic  measures  applied  to  abort  or  limit  inflam- 
mat(»ry  action. 

Treatment  of  Abscess  without  Fistula. — Abscess  has  been  de- 
scribed by  the  older  surgical  pathologists  as  the  process  through  which 
Nature  rids  herself  of  an  irritant.  This  is  in  a  measure  true,  but  it  is 
essentially  a  destructive  and  not  a  conservative  process.  Nature  does 
rid  herself  of  the  irritant  through  supj)iiration  ;  but  it  is  done  at  the 
expense  of  tissue  loss,  and  the  wise  surgeon  endeavors  to  remove  the 
irritant  and  limit  the  destruction.  After  the  inflammatory  action  has 
persisted  at  its  height  for  twenty-four  hours,  ])us  is  probably  present 
in  the  tissues  of  the  apical  region  ;  if  immediate  exit  be  given  to  the  pus 
the  inflammatory  symjitoms  will  subside.  If  the  tooth  be  not  so  sensi- 
tive as  to  preclude  touch  upon  it,  an  endeavor  is  made,  after  washing 
the  pnlp  chamber  with  powerful  antiseptics,  to  pass  a  very  fine  Donald- 
son's bristle  through  the  apical  foramen.  In  many  cases  this  may  be 
done  ;  the  pus  escaping  through  the  canal,  the  inflammatory  symptoms 
begin  to  subside.  This  is  a  case  of  acute  blind  abscess  ;  its  treatment 
will  be  first  discussed. 

The  conditions  existing  are  more  or  less  remnants  of  pulp  tissue 
undergoing  putrefactive  decomposition  ;  the  contents  of  the  dentinal 
tubules  are  also  in  process  of  dissolution.  Beyond  the  apical  foramen 
is  a  fibrous  tissue  containing  bloodvessels  and  nerves,  in  the  meshes  of 
which  tissue  ])us  is  forming.  Beyond  the  s|)ots  of  suj)pui'ation,  the 
tissues,  which  are  in  small  ])art  fibrous  but  are  niaiidy  osseous,  are  the 
seat  of  inflammation. 

The  pus  evacuated,  the  parts  tend  to  spontaneous  recovery  provided 


TREATMENT. 


479 


the  sources  of  irritation  be  removed.  The  first  step  in  sterilization  is 
the  destruction  of  putrescent  matter  in  the  pulp  canals.  If  the  tooth 
be  sore  after  evacuation  of  the  pus  through  the  apical  foramen,  the 
patient  is  directed  to  use  repeatedly  an  antiseptic  mouth-wash,  3  per 
cent,  pyrozone  or  any  of  the  solutions  of  hydrogen  dioxid,  and  report 
in  a  few  hours,  when  the  broach  is  again  passed  through  the  apex  of 
the  root,  the  canal  syringed  out  with  hydrogen  dioxid  and  dismissed  for 
twenty-four  hours,  when  the  inflammatory  symptoms  will  have  so  far 
subsided  as  to  permit  working  upon  the  tooth.  At  this  sitting,  a  slight 
flow  of  pus  will  still  be  found  ;  the  canals  are  syringed,  rubber  dam 
applied,  but  never  with  a  clamp  on  the  affected  tooth.  Sodium  di- 
oxid either  dry  or  in  50  per  cent,  solution  is  placed  in  the  canals,  and 
frequent  re-applications  made.  At  the  expiration  of  about  a  half-hour 
the  canals  and  abscess  cavity  are  syringed  out  with  an  acid  solution  of 
hydrogen  dioxid,  and  dried.  The  canals  will  now  be  sterilized  and  also 
the  general  abscess  cavity.  It  is  possible,  however,  and  probable,  that 
organisms  may  still  occupy  the  deeper  recesses  of  the  tissue  bounding 
the  abscess  cavity.  The  parts  forming  the  abscess  wall  are  of  com- 
paratively low  vitality  and  may  not  dispose  of  organisms  present  as 
would  be  done  in  more  vascular  tissues.  It  is  the  usual  practice,  there- 
fore, to  apply  to  them  a  powerful  antiseptic  :  campho-ph^nique,  Dr. 
Black's  1,  2,  3  mixture,  and  lysol  are  all  admirable  agents  in  this  par- 
ticular ;  they  are  pumped  into  the  abscess  sac  as  well  as  possible,  and 
the  excess  in  the  canals  wiped  away  with  wisps  of  cotton. 

There  will  be,  immediately  following  this  operation,  a  greater  or 
less  amount  of  exudation  from  the  abscess  walls,  which  diminishes  as 
granulation  proceeds  about  the  apex  of  the  root.  The  condition  is  one 
of  granulating  ulcer.  An  escape  is  provided  for  this  exudation  by 
leaving  the  dried  canals  unfilled  for  twenty-four  hours,  when  a  loose 
cotton  dressing  may  be  applied,  hermetically  sealing  the  cavity  com- 
municating with  the  saliva  after  each  dressing.  In  two  days  the  dress- 
ing is  removed,  always  sterilizing  the  tooth  walls  and  isolating  it  when 
the  cavity  is  to  be  opened.  On  the  third  day  a  larger  dressing  of 
cotton,  dipped  in  campho-phenique  and  wrung  out,  may  be  applied. 
After  two  days,  should  the  cotton  exhibit  little  or  no  evidence  of  exuda- 
tion, a  firmer  dressing  is  applied,  to  remain  about  four  days  ;  the  next 
dressing  remains  a  week,  when  the  abscess  cavity  should  be  filled  with 
tender  granulations.  Pending  the  organization  of  the  granulation  tissue 
there  is  probably  no  better  canal  filling  than  salol  having  a  core  of 
gutta-percha.  It  is  unirritating  and  may  be  applied  without  causing 
irritation.  Dilute  solutions  of  forraaldehyd  have  been  found  to  be 
extremely  useful  in  this  class  of  cases  as  Avell  as  in  all  cases  involving 
sterilization  of  the  pulp  canal.     The  high  antiseptic  value  of  formalde- 


480  DENTO- ALVEOLAR  ABSCESS. 

hyd  and  its  great  penetrating  power  placo  it  among  tlic  most  satisfactory 
agents  in  the  dental  pharmacopaMa.  For  tlie  treatment  of  root  canals 
M'ith  aj)i('al  pericementitis  a  wisp  of  cotton  moistened  with  a  5  per 
cent,  solntion  of  formalin  (the  40  per  cent,  solntion  of  the  gas  in 
water)  and  sealed  in  the  canal  will  in  a  few  honrs  completely  sterilize  it, 
so  that  usually  the  canal  may  be  permanently  closed  within  twenty-four 
hours.  Rarely,  a  second  dressing  is  required.  Stronger  solutions  of 
formalin  are  irritating  and  should  be  avoided,  as  they  may  cause 
necrosis  if  used  beyond  the  strength  stated,  or  even  in  that  strength 
if  used  in  too  large  quantity  or  too  frequently. 

Should  the  eifort  to  enter  the  apical  region  through  the  canal  fail,  and 
pus  be  present,  an  entrance  should  be  effected  through  the  gum.  At  a 
point  on  the  gum  immediately  overlying  the  aj)ex  of  the  attected  root, 
a  pointed  bistoury  is  cpiiekly  thrust  down  to  the  bone,  the  l)leeding  is 
encouraged  by  the  use  of  hot  water  for  several  miinites,  when  a  i)ellei 
of  cotton  wliieh  has  been  di])ped  into  95  per  cent,  carbolic  acid  is  laid 
against  the  periosteum  at  the  bottom  of  the  cut.  In  a  few  seconds  a 
spear  drill  driven  by  the  engine  is  j^assed  through  the  bone  into  the 
tissues  of  the  apical  region.  Any  bleeding  which  may  occur  is  encour- 
aged as  above  mentioned.  For  washing  the  incisions  and  the  abscess 
in  such  cases  there  is  no  agent  more  acceptable  than  a  20  per  cent,  solu- 
tion of  phenol  sodique,  it  being  both  sedative  and  antiseptic.  A  thread 
of  floss  silk  dipped  in  carbolic  acid  is  passed  into  the  fistula  to  the  seat 
of  abscess,  its  projecting  edge  lying  uj)on  the  gum  ;  this  will  prevent  too 
rapid  a  healing  of  the  fistula.  The  case  now  resembles  an  abscess  with 
a  fistulous  opening,  the  next  variety  of  acute  alveolar  abscess  ;  the  treat- 
ment for  both  is  the  same. 

Treatment  of  Abscess  "with  Fistula. — Cases  of  acute  alveolar 
abscess  discharging  through  a  fistulous  opening  are  either  seen  when 
the  pus  has  perforated  the  bone  and  is  making  its  exit  through  the  soft 
tissues,  or  in  cases  where  the  inflammatory  symptoms  run  high,  the 
usual  methods  of  al)orting  the  inflammation  having  failed,  pus  forms 
and  the  abscess  discharges  rapidly,  it  may  be  within  thirty-six  hours. 
The  use  of  pepper  plasters  and  like  devices  to  induce  pointing  of  an 
abscess  are  irrational ;  they  render  no  service  which  cannot  be  per- 
formed better  and  more  expeditiously  by  an  incision  made  down  to 
the  bone  by  means  of  a  sharp  bistoury.  In  all  cases  of  acute  apical 
pericementitis  where  the  swelling  of  the  gum  is  marked,  an  early  and 
deep  incision  is  useful  and  advisable.  If  pus  be  already  formed  and 
the  abscess  pointing,  escape  is  aflbrded  it  ;  if  the  })us  have  not  yet  per- 
forated the  periosteum  that  structure  receives  early  relief  from  a  condi- 
tion which  might  threaten  it.  The  greater  the  swelling  the  more 
imperative  is  the  necessity  for  this  incision,  which  must  be  freely  made. 


TREATMENT.  481 

A  sharp  curved  bistoury  is  held  as  a  pen,  its  point  directed  always 
toward  the  bone,  and  is  passed  boldly  down  to  the  bone  immediately 
over  the  apex  of  the  root. 

Inflammatory  symptoms,  as  a  rule,  subside  promptly  as  soon  as  exit 
is  aiforded  the  pus.  As  soon  as  the  tooth  may  be  operated  upon,  its 
canals  are  to  be  treated  as  virulently  and  deeply  infected  centres,  opened 
freely  and  sterilized  with  the  utmost  thoroughness.  The  usual  and 
satisfactory  method  of  accomplishing  this  is  by  means  of  a  50  per  cent, 
solution  of  sodium  dioxid ;  after  which  a  stout  syringe  filled  with  3 
per  cent,  pyrozone  is  to  have  its  contents  driven  forcibly  through  the 
abscess  tract,  the  application  to  be  repeated  until  the  peroxid  comes 
away  clear.  A  few  drops  of  campho-phenique  or  Dr.  Black's  1,  2,  3 
mixture  are  placed  in  the  pulp  canal  by  means  of  Flagg's  dressing 
pliers.  This  may  be  drawn  into  the  abscess  sac  along 
its  tract,  emerging  at  the  fistulous  opening,  by  a  little  ^^^-  ^'^^• 

device  of  Dr.  T.  M.  Hunter.^  One  of  the  rubber  cups 
used  for  finishing  fillings  and  cleaning  teeth  is  to  have 
its  tool  opening  filled  with  gutta-percha,  th&  concavity 
of  the  cup  moistened  and  pressed  flat  against  the  gum, 
covering  the  fistula ;  removing  the  pressure  from  the 
centre  of  the  cup  but  keeping  its  edges  closely  in  con- 
tact with  the  gum,  a  suction  is  created  drawing  the 
medicament  through  the  abscess  tract.  The  writer  has 
used  these  cups,  but  mounted  on  a  No.  300  mandrel 
(Fig.  458),  for  this  purpose  for  several  years ;  indeed 
the  discovery  that  Dr.  Hunter  had  employed  and  ad- 
vised it  as  a  means  of  emptying  abscess  cavities  was  a 
gratifying  surprise,  as  he  states  that  they  serve  this 
purpose  admirably. 

The  sterilized  canals  are  now  to  be  thoroughly  filled  with  cotton  twists 
or  gilling  twine  which  has  been  moistened  with  the  last-named  antisep- 
tic, or  5  per  cent,  formalin,  the  crown  cavity  sealed,  and  the  case  dis- 
missed. In  twenty-four  hours,  only  a  slight  serous  exudate  should  be 
pressed  from  the  fistula.  In  a  week  the  abscess  cavity  should  be 
healed.  In  that  time  a  permanent  canal  filling  may  be  inserted,  but  it 
is  wiser  to  defer  the  filling  of  the  crown  cavity  for  some  time — that  is, 
if  it  is  to  be  filled  with  cohesive  gold. 

In  case  of  acute  abscess  where  marked  inflammatory  symptoms  with 

involvement  of  neighboring  parts  persists  after  the  evacuation  of  the 

pus,  the  gum  overlying  the  tooth  being  purplish  and  tumid,  the  tooth 

very  loose,  and    no    diminution   of  the    attendant    fever,  neighboring 

structures  in  addition  to  the  tooth  are  in  danger,  and  the  latter  should 

^  Dental  Cosmos,  vol.  xxxiv.  p.  82. 
31 


482  DEyTO-ALVEOLAR  ABSCESS. 

be  extracted.  An  early  and  free  incision  will  Ireqncutly  axx-rt  this  con- 
dition and  necessity  t'or  extraction. 

Should  the  ease  when  first  seen  exhihit  marked  evidences  of  involve- 
ment of  the  tissnes  of  the  face,  a  threatening  of  the  abscess  towaixl 
pointinor  on  the  face,  prompt  and  active  measures  are  necessary.  As  a 
rule  in  these  cases  the  pernicicMis  domestic  practice  of  applying  poultices 
to  the  face  has  been  t'ollowed,  and  in  consequence  the  tissues  of  the 
cheek  are  distende<^l  and  softened,  lessening  the  suffering  but  inducing 
the  flow  of  pus  along  the  line  of  softening.  Compresses  wet  with  lead- 
water  and  laudanum — 

^l.  Plumbi  subacet.,  oj  ; 

Tr.  opii,  3}  ; 

Aqua%  Oj.— M. 

should  be  laid  upon  the  face,  and  an  incision  made  at  tlie  line  of  junc- 
tion of  the  cheek  with  the  gum,  down  to  the  bone  over  the  a}>ex  of 
the  root.  As  a  rule,  in  these  cases  the  pus  has  found  its  way  into  the 
tissues  of  the  cheek,  but  drains  thn^igh  the  incision  ;  a  cut  mnst  always 
be  made  away  from,  not  toward  the  cheek,  to  avoid  cutting  the  facial 
artery  or  any  of  its  branches.  Opening  upon  the  face  may  be  averted 
by  this  means,  even  when  the  pus  is  beneath  the  skin.  The  danger  of 
inclusion  of  the  duct  of  Steno  shoidd  be  borne  in  mind  should  the  case 
be  one  of  abscess  upon  an  upper  molar,  and  energetic  measures  pursued 
to  prevent  the  establishment  of  that  annoying  trouble,  salivary  fistula. 

When  fluctuati(^n  oi^  the  inflammatory  tumor  upon  the  face  becomes 
evident,  indicating  that  an  external  opening  mnst  be  made,  it  is  prefer- 
able that  it  be  made  with  a  sharp  knife  and  n«n  by  suppuration.  Sears 
left  bv  abscesses  discharging  spontaneously  are  irregular  and  disfiguring, 
those  following  clean  incision  are  but  a  line.  A  curved  bistoury  is  used 
to  transfix  the  summit  of  the  swelling,  the  knife  is  then  carried  outward, 
makinjr  an  incision  about  an  inch  long.  In  this  as  in  all  cases  of  abscess 
where  pus  is  detected  the  indication  is  to  give  it  immediate  exit. 

It  occasionally  occurs  that  abscess  may  be  found  upon  the  lateral 
aspect  of  a  tooth  containing  a  vital  pulp.  The  tooth  is  free  from 
caries,  and  is  perfectly  translucent.  The  most  usual  situations  of  these 
abscesses  are  upon  the  labial  faces  of  the  anterior  teeth  and  the  buccal 
faces  of  the  molars,  between  the  gingival  margin,  which  may  be  intact, 
and  the  apex  of  the  root.  As  a  rule  the  evacuation  of  the  pus  and 
dressing  with  antiseptics  causes  a  speedy  disa}ipearance  of  the  abscess. 
Left  to  themselves  they  discharge  as  a  rule  at  the  giun  margin.  They 
are  a  frequent  associate  of  the  condition  gra}»hically  described  by  Dr. 
G.  V.  Black  as  phagedenic  pericementitis.  Believers  in  the  gouty 
origin  of  this  disorder  note  their  occurrence  in  gouty  j^tients.*     In 

*  Typical  case:;  are  recorded  in  Proc.  Academy  of  Stomatology  0/  Philadelphia,  1895. 


TREAT3IEJS^T.  4S3 

these  cases  the  abscess  is  attended  by  more  or  less  destruction  of  the 
pericementum.  Cases  may  be  seen  in  which  the  abscess  involves  the 
tissues  near  the  apex  of  the  root,  the  pulp  being  vital ;  its  death,  how- 
ever, will  doubtless  residt  from  the  invasion. 

Acute  apical  abscess  may  discharge  at  the  margin  of  the  gimi,  follow- 
ing the  pericementum.  These  cases  are  to  be  treated  as  abscess  with 
fistula.  In  some  cases  subsequent  to  the  treatment  of  the  abscess  there 
appears  to  be  a  restoration  of  the  pericementum  lost  in  the  formation  of 
the  fistula.  In  others  a  permanent  loss  of  tissue  results.  This  mode 
of  discharge  is  common  about  dead  roots  which  have  been  in  the  jaw 
crownless  for  a  long  period ;  a  resorption  of  alveolar  process  has 
occurred  and  the  root  is  retained  by  fibrous  tissue.  The  treatment  in 
these  cases  is  that  accorded  any  and  all  roots  which  may  not  be  made 
ser\'iceable — extraction . 

Treatment    of    Chronic    Abscess. — For    purposes    of    treatment 
chronic  abscesses  are  divided  into  two  classes  :  those  discharsrinsr  throuarh 
the  pulp  canal,  what  are  known  as  blind  abscesses;    second,  those  dis- 
charging upon  the  gum,  at  the  neck  of  the  tooth  or  in  tact  at  anv  point, 
through  a  fistula. 

The  usual  condition  existent  with  the  blind  abscess,  is  a  cavity 
which  may  have  any  volume,  its  diameters,  however,  rarely  exceeding 
three-eighths  of  an  inch ;  this  cavity  is  bounded  upon  aU  sides  by  a 
fibrous  capsule,  analogous  to  the  indurated  surroundings  of  an  ulcer ;  the 
wall  represented  by  the  cementum  of  the  aifected  tooth-mav  be  devoid 
of  fibrous  tissue,  the  pericementum  being  necrotic.  The  pulp  chamber 
is  the  centre  of  infection  ;  the  abscess  cavity  is  the  habitat  of  bacteria, 
which  cause  the  peptonization  of  the  inflammatorv"  exudate  from  the 
wall  of  circumvallation,  and  destroy  the  exudation  corpuscles,  thus 
producing  a  continued  pus  formation.  The  observation  and  statement 
of  Dr.  Black  have  been  quoted  above,  wherein  he  states  that  gravity 
largely  determines  the  direction  pursued  by  the  pus  in  chronic  abscess. 
This  tendency  will  be  found  to  exist  with  the  blind  variety  also. 

The  tendency  of  long-continued  pus  formation  about  the  roots  of  the 
upper  teeth  will  be  to  progress  along  the  pericementiun,  resulting  in  a 
molecular  necrosis  of  that  structure  from  the  apex  downward.  The 
condition  is  represented  in  Fig.  459.  The  extent  to  which  the  apex  of 
the  root  projects  into  a  cavity  increases  with  the  progress  of  the  necrotic 
process. 

In  the  lower  teeth,  the  influence  of  gravity  carries  the  suppiurative 
process  away  from  the  apex  of  the  root,  the  abscess  cavity  increasing 
downward  (Fig.  460). 

If  the  case  be  seen  shortly  after  the  subsidence  of  the  inflammatory 
attack  which  may  have  ushered  in  the  suppurative  process,  the  cavitv 


484 


DElSTo-M  Vi:OLAR   ABSCESS. 


may  be  very  liiuitcil  in  size,  only  a  trilling  amount  ol"  the  pericementum 
being  destroyed. 

It  is  advisable  in  these  cases,  after  thorough  sterilisation  of  the  canals 
and  dentin  by  means  of  sodium  dioxid  or  formalin,  to  increase  the  si;^e  of 
the  natural  drainage-tube,  by  enlarging  the  pidp  canal ;  a  fine  Donaldson 

Fig.  459.  Fio.  460. 


Chronic  blind  abscess  of  upper  incisor,  showing  Chronic  blind  abscess  upon  lower  tooth, 

tendency  of  pus  to  jirojiressively  destroy  peri-  showing  tendency  of  pus  to  sink  into 

cementum  owing  to  the  inliuence  of  gravity.  the  snbstiinco  of  the  lower  maxilla 

owing  to  the  influence  of  gravity. 

cleanser  should  pass  freely  through  the  apical  foramen.  The  abscess 
cavity  is  now  forcibly  and  thoroughly  syringed  out  with  .'*>  per  cent, 
pvrozone.  It  is  advisable  after  effervescence  cea.ses  to  mechanically 
withdraw,  or  aspirate, the  contents  of  the  abscess.  This  may  be  readily 
done  by  passing  the  point  of  a  syringe  into  the  canal,  filling  around  it 
with  gutta-percha  and  withdrawing  the  piston,  when  the  contents  of  the 
abscess  will  flow  into  the  syringe.  Any  instrument  (syringe)  employed 
for  this  purpose  should  soak  for  hours  in  an  antiseptic  before  using  it 
in  other  cases  (a  20  per  cent,  solution  of  phenol  sodique  is  an  excellent 
sterilizing  agent) ;  the  same  syringe  should  never  be  used  for  any  other 
purpose.  A  small  amount  of  25  })er  cent,  pyrozone,  ethereal,  may  now 
be  placed  in  the  canals  and  pumped  into  the  abscess  cavity ;  then  canals 
and  sac  are  dried  l)y  means  of  warm  blasts,  and  a  wisp  of  cotton  dipped 
in  campho-phenique  and  wrung  out  is  packed  in  the  canal.  The 
patient  reports  the  day  following,  and  if  no  discomfort  be  felt  the  tooth 
remains  closed  until  the  following  day.  If  upon  opening  the  tooth  no 
evidence  of  exudation  is  seen,  and  no  effervescence  occurs  upon  applica- 
tion of  3  per  cent,  pyrozone,  the  drying  and  dressing  are  renewed,  to 
remain  about  three  days.  If  any  evidence  of  pus  be  detected,  the  canals 
and  abscess  are   syringed  with  weak  pyrozone,  and  a   small  amount 


TREATMENT.  435 

of  campho-phenique,  Dr.  Black's  1,  2,  3  mixture,  or  myrtol  may  be 
pumped  into  the  abscess,  and  by  repeated  blowing  of  warm  blasts  driven 
into  all  parts  of  the  cavity.  In  twenty-four  hours  a  slight  serous  flow 
should  be  observed,  but  if  after  three  days  any  evidence  of  pus  be  de- 
tected, it  is  the  signal  to  establish  an  external  fistula.  This  is  done  in 
the  manner  before  described.  The  treatment  is  now  the  same  as  that 
for  the  next  class  :    chronic  abscesses  having  fistulous  opening. 

Chronic  Abscess  with  Fistulous  Opening. — In  these  cases  the 
canals  are  opened  and  sterilized  as  in  all  others  by  the  powerful  anti- 
septics named.  The  abscess  tract  is  syringed  out  with  3  per  cent,  pyro- 
zone  until  bubbling  at  the  external  orifice  ceases.  The  canals  are  filled 
with  campho-phenique,  or  the  1,  2,  3  mixture,  after  the  dressing-pliers 
method,  and  drawn  into  and  through  the  abscess  cavity  and  tract  by 
means  of  the  rubber-cup  device  already  mentioned.  In  cases  in  Avhich 
the  rubber-cup  device  fails  to  cause  a  flow  of  the  medicament  from  the 
pulp  chamber  out  through  the  fistulous  tract,  the  result  may  be  attained 
by  filling  the  canals  and  pulp  chamber  with  the  fluid  desired ;  for 
example,  campho-phenique  or  strong  carbolic  acid,  and  then  placing 
over  the  cavity  a  pellet  of  unvulcanized  caoutchouc  or  warmed  and  soft- 
ened gutta-percha  base  plate  and  exerting  strong  pressure  upon  it  with 
a  ball-end  burnisher  just  enough  smaller  than  the  cavity  to  force  the 
material  well  into  the  pulp  chamber.  This  will  cause  the  medicine  to 
flow  out  at  the  fistulous  opening,  where  in  the  case  of  carbolic  acid  its 
presence  will  be  manifested  by  its  coagulating  effect  upon  the  margins 
of  the  fistulous  orifice. 

The  canals  are  to  be  temporarily  filled  with  cotton  saturated  with  an 
antiseptic,  and  as  a  rule  the  case  proceeds  rapidly  to  recovery.  Fresh 
cleansing  and  dressing  are  indicated  if  all  evidences  of  inflammatory 
action,  seen  •  in  the  gum  color,  are  not  absent  in  three  days ;  in  a  M^eek 
the  external  fistula  should  be  closed. 

If  after  a  week  the  fistula  remain  open,  discharging 
serum,  a  sterilized  excavator  is  passed  through  the 
fistula  and  it  may  detect  denudation  and  roughness  of 
the  apical  cementum.  After  a  root  has  been  the  seat 
of  chronic  apical  abscess  for  a  long  period,  not  only 
may  the  apical  pericementum  be  destroyed  (Fig.  461), 
but  the  cementum  itself  may  become  saturated  with 
the  products  of  decomposition  and  invaded  by  septic  chronic  abscess :  show- 
organisms.  It  is  not  uncommon  to  find  deposits  of  ing  denudation  of 
11.  J.I,       J  J     1  J.  C!      1,  ^Pex  of  root  (a  to  6), 

calculi  upon  the  denuded  cementum.  buch  an  apex  ^j^j^  deposits  of  cal- 
ls the  source  of  constant  irritation ;  it  is  a  foreign  cuius  upon  cemen- 
body,  and  is  to  be  removed. 

The  operation  of  removal  is  technically  known  as  amputation  of  the 


486  DEXTO- ALVEOLAR  ABSCESS. 

apex.  The  canal  t'noruughly  stcrilizccl  is  to  hv  solidly  lilli-d  with  jjutta- 
jH'ivha.  A  vortical  incision  is  nuulc  Nvliich  inchules  the  fistula  and 
exposes  the  process  ;  the  opening  through  the  process  is  enlarged,  by 
sweeping  around  its  Ixtrders  a  large  dentate  bur.  The  incision,  open- 
ino-and  abscess  cavity  are  now  packed  with  cotton  saturated  with  phenol 
sodique,  until  all  l)leeding  ceases. 

The  necrosed  cenicntum  is  now  exposed  ;  a  small  and  extremely  sharp 
fissure  bur,  driven  rapidly,  is  laid  against  the  distal  wall  of"  the  root  and 
a  constant  pressure  upon  the  bur  maintained  until  the  dead  part  is  ampu- 
tated. A  sharp  scaler  may  now  be  employed  to  round  the  edges  of  the 
root  and  make  the  cut  surface  smooth. 

The  cavity  is  syringed  with  phenol  sodique,  to  thoroughly  remove 
all  blood-clots — favorable  breeding-grounds  for  organisms  ;  as  a  final 
measure  the  walls  are  touched  with  campho-phenique,  and  the  edges  of 
the  incision  brouirht  toijether,  usintj  if  necessarv  a  stitch  to  unite  the 
upper  edges.  In  the  abscess  cavity  iodoform  or  nosophen  gauze  is  to 
be  packed,  and  renewed  in  a  couple  of  days.  For  a  week  the  patient 
is  directed  to  employ  repeatedly  a  mouth-wash  of  3  per  cent,  pyrozone. 
No  attempt  should  be  made  to  fill  such  a  tooth  with  cohesive  foil  fi)r 
several  months. 

In  some  of  the  cases  of  anomalous  root  form,  such  as  a  sharp  bend 
upon  the  upper  end  of  the  root,  and  which  renders  it  impossible  to 
gain  access  to  the  apex  of  the  root  even  through  the  aid  of  sulfuric  acid, 
it  may  be  necessary  to  treat  the  abscess  through  the  fistulous  opening. 
The  roots  are  sterilized  and  cleansed  to  as  great  a  depth  as  possible  by 
the  aid  of  sulfuric  acid  and  fine  cleansers,  and  the  endeavor  made  to 
force  hydrogen  dioxid  through  the  apical  foramen  and  out  of  the  fistula 
by  means  of  a  syringe.  The  cavity  of  the  crown  is  filled  with  pink 
gutta-percha,  and  through  it  the  n(»zzle  of  a  syringe  filled  with  3  per 
cent,  pyrozone  is  thrust,  well  up  the  canal.  The  piston  of  the  syringe 
is  forced  down  ;  it  may  be  the  solution  will  appear  at  the  opening  of 
the  fistula,  or  it  may  be  the  solution  will  fail  to  penetrate  the  fora- 
men and  its  backward  pressure  will  force  the  gutta-jiercha  from  posi- 
tion. In  that  event  myrtol  is  placed  in  the  canal,  which  is  filled  with 
thread  holding  the  same  material.  Three  per  cent.  ])yrozone  is  injected 
into  the  abscess  cavity  through  the  fistula,  until  effervescence  ceases. 
The  nozzle  of  a  minim  syringe  (Fig.  429).  charged  with  campho- 
phenique  or  the  1,  2,  3  mixture  is  passed  into  the  abscess  sac,  and  a 
couple  of  drops  deposited.  In  very  many  cases  the  abscess  will  then 
proceed  to  recovery.  The  treatment  should  be  repeated  if  necessary. 
If  several  dressings  applied  at  intervals  of  a  week  do  not  cause  a 
disappearance  of  pus  formation,  amputation  of  the -offending  portion 
of  the  root  will  be  necessarv.     An  heroic  method  of  treatinjr  chronic 


TREATMENT.  437 

abscesses  which  obstinately  refuse  to  heal  is  by  extraction  and  replanta- 
tion. The  method  applies  alone  to  single-rooted  teeth,  although  it  has 
been  successfully  performed  upon  molars. 

The  patient's  mouth  is  to  be  sterilized,  and  the  tooth  extracted.  It 
is  immediately  placed  in  a  solution  of  1  :  1000  mercuric  chlorid  at  a 
temperature  of  120°  F.  It  has  been  repeatedly  asserted,  however,  with- 
out satisfactory  demonstration,  that  the  cells  of  the  deeper  layer  of  the 
pericementum  and  the  cementoblasts,  and  also  the  cement  corpuscles 
retain  their  vitality  for  some  period  after  extraction,  and  immediate 
replantation  results  in  a  re-establishment  of  the  physiological  union 
between  the  tooth  and  alveolus.  It  is  certain  that  means  and  measures 
which  are  necessary  to  thoroughly  sterilize  the  tooth  before  its  reinser- 
tion would  be  fatal  to  any  cellular  vitality  which  might  exist  in  the 
cementum  and  its  covering. 

The  pulp  canal  is  opened  from  its  apex  and  cleaned  out  with  canal 
cleansers,  and  pyrozone  25  per  cent,  placed  in  the  canal,  where  it  is  al- 
lowed to  remain  for  some  time.  In  the  meantime  the  socket  from  which 
the  tooth  has  been  removed  is  syringed  out  with  pyrozone,  and  should 
the  pericementum  not  be  adherent  to  the  tooth,  the  depth  of  the  socket 
is  scraped  by  means  of  large  spoon  excavators  to  remove  the  tissues 
implicated  in  the  abscess.  The  cavity  is  washed  out  with  pyrozone, 
and  a  pledget  of  cotton  which  has  been  dipped  in  campho-phenique  is 
placed  in  the  socket  at  its  bottom.  The  tooth  is  dried  by  means  of 
warm  air ;  the  soft  tissues,  if  any  be  present,  at  the  apex  are  cut  away 
for  about  one-eighth  of  an  inch.  The  canal  is  filled  with  gutta-percha 
or  solidly  filled  with  gold,  the  end  of  the  root  cut  off  as  far  as  it  has 
been  denuded  of  pericementum,  smoothed,  and  returned  to  the  antiseptic 
solution.  The  cotton  is  removed  from  the  tooth  socket,  which  is 
syringed  out  with  3  per  cent,  pyrozone,  and  the  tooth  returned  to  posi- 
tion. It  is  tied  to  the  adjoining  teeth  by  means  of  silk  ligatures  or  held 
in  place  by  an  appropriate  retaining  appliance. 

Occasionally  the  seat  of  an  alveolar  abscess  may  be  at  the  bifurca- 
tion of  the  roots  of  a  molar.  This  may  occur  upon  vital  teeth  owing 
to  a  foreign  body  being  driven  beneath  the  margin  of  the  gums  and  into 
the  point  of  bifurcation.  In  these  cases  it  is  noted  that  the  inflamma- 
tion affects  the  gum  about  the  neck  of  the  tooth ;  over  the  apices  of  the 
roots  there  may  be  no  evidences  of  inflammation ;  pus  forms  and  dis- 
charges quickly.  Syringing  out  the  tract  with  3  per  cent,  pyrozone 
usually  frees  it  from  pus  and  the  offending  substance — it  may  be  a 
bristle  of  a  toothbrush — and  the  case  heals  rapidly. 

Cases  are  seen  in  which  the  gum  attachment  about  the  neck  of  the 
tooth  is  unbroken  ;  and  free  access  may  be  had  to  the  apex  of  each 
root  of    a  tooth   manifestly  suffering  from  acute  pericementitis,  pre- 


i S S  DP:y TO-AL  VEO LMl   A  liSCESS. 

suiii:il)Iv  due  ton  |nitrcsc<'iit  |)iil|).  In  :i  tl;iy  or  two  a  (liscliarti'c  of 
pus  iiiav  he  noted  aWoiit  tlic  Jicck  of  tlic  tootli.  Such  tci'tli  when 
extracted  exhibit  an  unmistakable  abscess  sac  in  tlie  pericementum  at 
the  bifurcation  of  the  roots.  Whether  the  pyogenic  organisms  have 
traversed  the  dentin  in  the  bottom  of  the  pulp  chamber  and  the 
cementum  beneath,  and  thus  inaugurated  the  suppurative  process,  is 
undetermined  ;  it  may  be,  however,  that  waste  jiroducts  from  this 
soui-cc  i'oUowing  the  channel  named  may  have  saturatetl  the  cementmn 
with  noxious  material  and  caused  the  inflammation,  or  the  organisms  may 
have  found  entrance  at  the  gum  margin.  The  diagnosis  of  such  a  con- 
dition is  most  uncertain  before  pus  finds  exit  at  the  gum  margin.  Such 
a  case  is  to  be  treated  by  sodium  dioxid,  full  strength,  placed  in  the 
floor  of  the  cavity,  frequently  washed  away  and  renewed  until  the  base 
of  the  ])ulp  chamber  is  bleached  white.  The  abscess  cavity  is  syringed 
out  with  pyrozone. 

Another  variety  of  abscess  should  receive  mention  :  that  occurring 
about  lower  third  molars,  affecting  the  gum  tissues  partially  enclosing 
the  emerging  crown.  The  gimi  overlying  and  surrounding  the  erupting 
tooth  becomes  reddened,  tumid,  and  exquisitely  sensitive ;  if  the  inflam- 
mation be  not  aborted  by  timely  incision  and  antiseptic  washes,  pus  may 
form,  and  the  ginn  acquire  an  ulcerous  a^jpearance.  The  treatment  is 
free  incision,  dividing  the  swollen  gum,  and  syringing  with  8  per  cent, 
pyrozone.  If  there  be  ulcerous  surfaces  they  are  to  be  touched  A^•ith  50 
per  cent,  solution  of  trichloracetic  acid. 

Occasionally  the  muscles  of  mastication  may  become  affected  by  the 
inflammatory  process,  and  inability  to  open  the  jaws  result.  Such  cases 
are  not  uncommon  when  the  eruption  of  the  tooth  is  delayed  by  lack  of 
room  between  the  ramus  of  the  jaw  and  the  second  molar.  The  extrac- 
tion of  this  latter  tooth  may  be  required  before  relief  is  secured. 

Complications  of  Alveolar  Abscess. 

The  complications  of  alveolar  abscess  are  due  in  acute  cases  to  the 
involvement  of  other  tissues  than  those  commonly  affected  in  the  course 
of  abscess  formation  and  discharge.  They  depend  in  great  part  upon 
peculiarities  of  the  anatomical  relations  existing  between  teeth  and  their 
surroundings,  and,  as  anatomical  variations  are  not  uncommon  in  these 
jnu'ts,  aberrations  of  disease  process  may  be  found  with  unwelcome  fre- 
quency. An  examination  of  some  of  Dr.  Cryer's  sections '  will  exhibit 
in  one  case  the  root  of  a  lower  second  bicuspid  penetrating  the  passage- 
way for  the  inferior  dental  vessels  and  nerves.  It  is  quite  possible  that 
an  abscess  upon  such  a  tooth  discharging  about  the  fibrous  sheaths  of 

^  Proc.  of  American  Dental  Association,  1895. 


COMPLICATIONS  OF  ALVEOLAR  ABSCESS.  489 

these  vessels  might  travel  to  distant  parts — backward  through  the  in- 
ferior dental  foramen,  or  forward  through  the  mental  foramen. 

The  roots  of  molar  teeth  instead  of  having  their  thinnest  bony  cov- 
ering overlying  their  buccal  aspects,  may  have  their  apices  almost  per- 
forating the  lingual  wall  of  the  bone  ;  in  others  the  apex  of  the  root  of 
a  lower  molar  is  found  beneath  the  line  of  insertion  of  the  mylo-hyoid 
muscle.  Abscess  from  such  a  ease  as  this  would  probably  discharge  not 
into  the  cavity  of  the  mouth,  but  in  the  submaxillary  triangle.  (See 
the  case  of  Dr.  Cryer's  noted  early  in  the  chapter.)  Dr.  Harrison 
Allen '  records  one  of  these  cases.  The  septic  roots  of  a  lower  third 
molar  were  the  exciting  cause  of  pericementitis,  followed  by  osteitis 
and  maxillary  periostitis.  Pus  found  exit  beneath  the  mylo-hyoid 
muscle  and  gravitated,  forming  a  collection  about  the  hyoid  bone,  and 
from  that  point  passed  upward  upon  the  face  in  the  line  of  the  facial 
artery.  The  abscess  in  addition  pressed  directly  upward  against  the 
floor  of  the  mouth  and  caused  unilateral  glossitis,  from  the  mechanical 
effects  of  which  upon  the  organs  of  respiration  the  patient  died.  The 
duration  of  the  extra -maxillary  complication  was  but  four  days. 

In  the  progressive  resorption  of  the  inner  substance  of  the  superior 
maxillary  bone  which  results  in  the  formation  of  the  maxillary  sinus,  a 
process  which  certainly  continues  longer  in  some  persons  than  in  others, 
the  bony  structures  may  be  removed  to  such  an  extent  that  but  a  thin 
layer  of  bone,  periosteum  and  mucous  membrane  covers  the  apices  of 
the  roots  of  molars.  Dr.  Cryer's  sections  exhibit  two  cases  in  which 
the  excavation  of  the  sinus  has  proceeded  down  between  the  roots  of  an 
upper  molar,  creating  such  a  condition  that  abscess  upon  either  palatal 
or  buccal  roots  must  almost  inevitably  discharge  into  the  sinus.  No 
doubt  many  cases  of  incipient  empyema  of  the  antrum  are  aborted  by 
the  early  extraction  of  abscessed  molars,  the  antral  complication  being 
unrecognized.  It  is  presumable  that  most  of  the  cases  of  empyema  of 
the  antrum  afford  subjective  evidence  comparatively  early,  owing  to  the 
lighting  up  of  inflammation   and  purulent  catarrh. 

The  student  is  advised,  in  studying  the  relations  of  the  teeth  with  the 
maxillary  sinus,  to  a  careful  and  repeated  reference  to  the  sections  of 
Dr.  Cryer.  He  calls  attention  to  a  fact  frequently  overlooked  and  un- 
taught, that  the  orifice  or  opening  connecting  the  maxillary  sinus  with 
the  nasal  passage  is  near  the  roof  of  the  former,  so  that  while  the  patient 
is  in  the  erect  position  collections  of  fluid  must  nearly  fill  the  sinus 
before  there  is  a  discharge.  In  the  recumbent  position,  however,  the 
fluid  escapes  and  may  be  found  in  the  nostril  of  one  side.  This  is 
symptomatic  of  antral  empyema.  In  acute  cases  of  the  antral  disease 
there  is  much  swelling,  oedema  about  the  eyelid,  etc, ;  sharp  lancinating 
^  Garretson'  s  Oral  Surgery,  6th  edition. 


4;10  DKSTO-ALVKOI.Ml  ABSCESS. 

]);iiiis  thirt  alxiiit  tlic  jaw.  In  the  clu'oiiic  cases,  laruc  accmmilations  of 
j)iis  inav  (icciir  and  not  he  tlctfclcd  until  the  Ixtnc  is  thin  and  hul^od, 
emitting;  a  eracklinji;  sovind  upon  pressure.  Ivxtraetion  of"  the  ott'ending 
tootli  furnishes  an  outlet  for  the  jms. 

It  is  usual  to  attenij)t  the  passage  of  an  in.-truinent  through  the 
])ulp  eanals  into  the  antrum  and  endeavor  to  preserve  the  tooth.  Sueh 
a  drainage  is  insuttieient  ;  the  wall  of  the  antrum  shoidd  be  perforated. 
'i1ii-  little  operation  is  readily  done  :  At  a  point  about  one-eighth  of  an 
inch  or  more  al)ove  the  ai)i«'es  of  the  roots  of  the  molars  an  incision  is 
made  througii  the  mucous  membrane  of  the  buccal  alveolar  wall,  clear 
to  the  bone  ;  a  spear-j)ointed  drill,  a  large  one  (h'iveu  rapidly  l)y  the 
engine,  is  passed  instantly  througii  the  outer  antral  wall.  The  drill 
is  directed  upward  and  inward.  The  opening  is  made  sutliciently  large 
to  permit  free  irrigation.  Into  the  opening  thus  made  the  point  ol'  a 
syringe,  perforated  to  sprinkle,  is  placed,  and  the  cavity  washed  out 
with  3  per  cent,  pyrozone  which  has  been  diluted  one-half  and  made 
faintly  alkaline  by  the  addition  of  sodium  dioxid.  As  pointed  out  by 
Dr.  W.  H.  Atkinson  many  years  ago,  unless  the  irrigating  fluid  be 
made  faintly  alkaline  it  is  irritating.  As  a  stimulant  injection  to  fol- 
low, Lugol's  solution  (licpior  iodi  eompositus,  gtt.  xx  to  the  ounce)  is 
excellent.  The  canal  of  the  tooth  is  to  be  thoroughly  sterilized  and 
tilled. 

In  the  treatment  of  other  eomj)lications,  if  the  ease  be  acute,  the  im- 
mediate extraction  of  the  offending  tooth  and  the  free  use  of  antiseptic 
mouth-washes  will  usually  effect  a  cure.  In  the  treatment  of  chronic 
cases,  if  the  focus  of  infection,  the  pulp  canals,  be  made  antiseptic  and 
the  medicinal  agents  can  be  introduced  into  the  abscess  tract  through- 
out, surprising  ciu'es  may  result,  as  the  literature  of  dentistry  testifies. 

Abscess  upon  Temporary  Teeth. — Aiuong  the  most  trying  classes 
of  cases  with  which  the  dental  operator  is  confronted  are  those  of  peri- 
cemental disturbance  affecting  the  temporary  teeth.  The  operator  is 
torn  by  conflicting  emotions  :  the  desire  to  afford  quick  relief  to  the  little 
sufferers  and  the  hesitancy  or  dread  of  inflicting  the  amount  of  suffering 
necessary  to  relieve  the  acute  pain.  Fortunately  the  ])ain  is  relatively 
less  than  in  adults  ;  the  tissues  being  softer  the  child  escapes  the  agoniz- 
ing ])ain  attending  the  rapid  formation  of  ]>us  in  the  aj)ical  tissues  of  the 
adult.  The  swelling,  redness,  and  febrile  distiu'bance  are  usually  greater 
in  the  child  than  in  the  adult ;  pus  forms  more  quickly  and  makes  its 
appearance  in  the  gum  sooner.  The  principle  of  treatment  is  the  same 
as  with  the  adult — evacuation  of  the  pus.  The  necessary  incision  may 
be  made  almost  ])ainlessly  by  employing  a  sharp-pointed  bistoury  hav- 
ing a  razor-like  edge.  The  child,  reassured  by  a  gentle  examination 
and  firm  kindnes.s,  is  directed  to  open  the  mouth  and  close  the  eyes, 


COMPLICATIONS  OF  ALVEOLAR  ABSCESS.  491 

when  the  bistoury,  held  as  a  pen,  is  passed  quickly  into  the  swell- 
ing. 

The  canals  of  temporary  teeth  are  to  be  sterilized  first  with  pyrozone, 
next  with  oil  of  cassia,  and  should  be  filled  with  "  balsamo  del  deserto." 
Dr.  W.  H.  White,  to  whom  we  are  indebted  for  the  introduction  of  this 
material,  states  that  in  roots  of  temporary  teeth  in  which  it  has  been 
placed  the  resorptive  process  is  not  interfered  with. 

Abscess  occurring  upon  temporary  teeth  should  receive  prompt  at- 
tention and  treatment  to  avoid  possible  injury  to  the  permanent  tooth 
beneath  ;  this,  however,  does  not  appear  to  be  as  frequent  as  might  be 
supposed.  There  is  a  tendency  in  strumous  children  toward  marked 
lymphatic  involvement  attending  alveolar  abscess ;  and  secondary 
abscess  of  the  lymphatic  glands  is  not  uncommon. 

Chronic  abscess  in  the  cachectic  individual  which  may  not  respond 
to  the  usual  local  measures  of  treatment  may  be  materially  benefited 
by  constitutional  treatment.  This  comprises  regulation  of  the  functions 
of  the  alimentary  canal ;  the  use  of  such  foods  as  beef  peptonoids,  mal- 
tose, etc.  Iron  and  arsenic  are  administered  when  the  patient  is,  as  is 
usually  the  case,  anemic.  More  important  than  any  medicinal  thera- 
peutics is  systematic  exercise  in  the  open  air.  Raising  the  bodily  tone 
raises  the  recuperative  power  of  the  tissues,  and  hitherto  resisting  dis- 
ease may  be  conquered. 

Perforated  Roots. — Perforation  of  the  walls  of  a  root  canal  expos- 
ing the  pericementum  occurs,  as  a  rule,  in  consequence  of  two  causes  : 
first,  the  invasion  of  dental  caries  ;  second,  the  injudicious  or  unskilful 
use  of  the  reamer  employed  in  enlarging  canals,  or,  it  may  be,  burring 
through  the  walls  in  the  forming  of  a  socket  for  the  reception  of  the 
post  of  an  artificial  crown. 

The  direct  consequence  of  the  perforation  is  inflammation  of  the 
pericementum,  and  the  usual  result  is  ulceration  of  that  structure.  The 
symptoms  and  their  severity  are,  as  a  rule,  governed  by  the  situation  of 
the  perforation.  If  this  be  at  the  lower  half  (toward  the  crown)  of  the 
root,  there  is  usually  a  proliferation  of  tissue  which  intrudes  upon  the 
pulp  chamber.  This  hypertrophied  tissue  may  increase  in  amount,  a 
resorption  of  the  edge  portion  of  the  process  occur,  and  a  fungous  mass 
bearing  a  close  resemblance  to  fungous  pulp  bulge  into  the  pulp  cham- 
ber. In  fact,  in  many  cases  it  is  impossible  to  distinguish  between 
the  naked-eye  appearance  of  fungous  pulp  and  the  condition  under 
discussion.  The  growth  fills  the  pulp  chamber  and  obscures  the  per- 
foration ;  it  is  in  addition,  in  many  cases,  exquisitely  tender.  In  either 
event,  whether  pulp  or  hypertrophied  gum,  it  is  necessary  to  remove 
the  growth. 

A  spray  of  ethyl  chlorid  directed  against  the  mass  is  perhaps  the 


4}H>  DENTO- ALVEOLAR  ABSCESS. 

most  I'ttW'tivc  :inc>tlicti<'  ;  in  a  few  iniiiiitc-  :i  sliar))  tinc-poiiitcd  lancet  is 
passed  aroinid  the  <i:n»\vtli  as  tar  as  it  can  !)c,  and  the  excised  portion 
removed.  An  application  of  tannin  will  check  the  l)leedin«;  ;  pledtrcts 
of  cotton  dipi)ed  in  tr.  iodin.  are  packed  against  the  remainder  of  the 
jirowth  and  covered  in  with  cotton  and  .sandarac  varnish  for  twenty- 
fonr  honrs.  This  dressing  is  renewed  from  day  to  day  until,  if  it  be  a 
fungous  gum,  the  margins  of  the  perforation  are  plainly  seen.  The 
canal  is  cleansed,  sterilized,  dried,  and  filled  with  salol  and  gutta-percha, 
or  with  paraffin  and  gutta-percha,  to  about  half  its  depth.  The  re- 
mainder of  the  canal  and  crown  cavity  arc  washed  out  with  25  per  cent. 
j)yrozone,  and  a  ilrcssing  of  temporary  stopping  applied,  filling  the  per- 
foration and  yet  not  exercising  much  pressure  upon  the  soft  tissues.  In 
two  davs  the  temporary  stoj)i)ing  is  removed  and  the  cavity  is  washed 
out  with  .3  per  cent,  pyrozone  and  dried.  A  piece  of  No.  GO  gold  is  cut, 
larger  than  the  aperture  ;  this  is  dipped  in  chloro-percha  and  laid  over 
the  perforation.  A  disk  of  gutta-percha  larger  than  the  j)iece  of  foil  is 
warmed,  laid  upon  the  foil,  and  pressed  against  it,  sealing  it  to  the 
cavity  walls.  The  remainder  of  the  cavity  is  then  filled  with  zinc  phos- 
phate. 

In  case  the  perforation  siiould  be  nearer  the  apex  of  the  root  the  dif- 
ficulty is  greatly  increased.  Attempts  at  passing  cleansers  to  the  apical 
foramen  usually  result  in  pricking  the  pericementum  at  the  perforation 
and  a  flow  of  blood  follows,  filling  the  canal.  The  cleansers  are  bent  so 
that  in  passing  them  to  the  apex  they  press  against  the  wall  opposite 
the  perforation  ;  the  apical  portion  of  the  canal  may  be  detected  and 
cleansed  after  this  manner  in  some  cases.  The  temporary  dressings  in 
these  canals  should  be  one  of  the  antiseptic  oils,  cassia  or  myrtol.  A 
dressing  of  oil  on  cotton  should  remain  a  week,  and  no  attempt  at  canal 
filling  be  made  until  all  evidences  of  pericemental  disturbance  vanish. 
A  fine  cone  of  gutta-percha  is  passed,  when  practicable,  into  the  canal 
beyond  the  perforation  ;  the  remainder  of  the  canal  is  filled  with  chloro- 
percha,  and  the  silk  points  covered  with  gutta-])ercha.  The  canal  at 
the  proximal  side  of  the  perforation  is  filled  with  the  solution,  by  means 
of  the  long  dressing  pliers,  the  gutta-percha-covered  silk  being  carried 
gently  in  position  while  the  general  mass  is  fluid.  Balsamo  del  deserto 
should  apply  well  in  these  cases.  The  canal  is  filled,  or  partially  filled, 
with  the  material,  and  a  large  gutta-percha  point  introduced. 


CHAPTER    XIX. 
PYORRHEA  ALVEOLARIS. 

By  C.  N.  Peiece,  D.  D.  S. 


Definition. — "  Pyorrhea  alveolaris  "  is  a  generic  term  which,  strictly 
defined,  means  a  flowing  of  pus  from  an  alveolus.  It  describes  merely 
a  symptom  which  may  be  and  usually  is  attendant  upon  a  variety  of 
disorders.  The  term  is  applied  in  clinical  dentistry  to  a  complexus  of 
pathological  conditions  which  more  or  less  clearly  indicate  a  specific 
disease.  As  the  term  is  now  understood,  pyorrhea  alveolaris  includes  all 
of  those  cases  of  morbid  action  characterized  by  the  following  features : 
A  molecular  necrosis  of  the  retentive  structures  of  the  teeth  (their  liga- 
ment, the  pericementum),  an  atrophy  of  the  alveolar  walls,  together  with 
a  chronic  hyperemia  of  the  gum  tissue  which  leads  to  limited  hypertro- 
phy. After  a  variable  period  the  teeth  drop  out,  and  the  morbid  action 
ceases  with  their  loss.  An  examination  of  the  roots  of  the  teeth  before 
or  after  their  exfoliation  usually  exhibits  deposits  of  calculi  upon  their 
surfaces.  The  disease  is  generally,  though  not  always,  attended  by  a  flow 
of  pus  from  the  alveoli. 

History. — That  pyorrhea  alveolaris  is  not  a  recent  disease,  or  one 
due  to  modern  constitutional  states  alone,  is  rendered  evident  from  the 
examination  of  the  skulls  of  ancient  as  well  as  modern  races.  The 
alveolar  processes  of  many  crania  widely  separated  both  in  time  and  in 
locality  exhibit  marked  impairment  of  structure  which  bears  the  closest 
resemblance  to  that  presented  by  processes  which  were  known  to  have 
been  the  result  of  pyorrhea  during  life. 

Recorded  observations  of  this  disorder  date  at  least  as  far  back  as 
1746,  when  M.  A.  Fauchard  described  its  essential  clinical  features,  but 
failed  to  designate  it  by  any  specific  term.  Following  this,  communica- 
tions describing  the  disease  were  published  by  Jom'dain  in  1778,  by 
Toirac  in  1823,  and  by  M.  Marechal  de  Calvi  in  1860,  in  which  it  was 
described  as  a  "  conjoint  suppuration  of  the  gums  and  alveoli,"  pyorrhea 
inter-alveolo-dentcdre,  and  gingivitis  expidsiva  respectively. 

The  most  important  contribution  to  the  knowledge  of  the  nature  of 

493 


194  pvorrufa  alvkolaris. 

tlio  disease  wliicli  had  iij)  ti)  tlial  dale  Ix'cn  made  was  h\  Dr.  K.  Magitot 
in  lS(j7.  In  his  paper  he  states  that  the  disi'ase  is  charaeterizod  by  a 
slow  but  jx'oirrt'ssive  iullaiuniatioii  (h'stnietive  (tf"  the  periosteal  meni- 
braiie  and  eementuni,  proeeediiiii-  tVoin  the  neck  to  the  apex  of  the  root 
and  iiivolviiiii'  the  loss  of  the  teeth.  I'^roin  the  exact  seat  ol"  the  lesion 
he  desitiiiated  the  disease'  ostcn-prrioxfiii  (i/rco/o-dcnfdin'.  Soon  after  the 
appearance  of  the  periosteal  inHaniniation,  it  became  conij)licated  with 
diseases  of  the  gums  and  the  osseous  walls  of  tlie  alveolus,  though 
these  are  never  primarily  the  seat  of  InHaniniation.  Magitot  regarded 
the  causes  of  the  iuHammatiou  as  very  coinjilex,  and  to  be  sought  ibr 
not  in  the  teeth  and  gums,  but  in  certain  conditions  of  the  general  nutri- 
tion. The  gouty  and  rheumatic  presented  the  disease  most  frequently, 
though  its  presence  in  those  suffering  from  diabetes  and  albuminuria 
was  extremely  common.  The  deposition  of  tartar  on  the  roots  of  the 
teeth,  which  might  at  first  glance  be  regarded  as  playing  an  important 
part  in  the  causation  of  the  disease,  Magitot  considered  as  accidental 
and  not  to  be  looked  upon  as  a  causative  agent,  ^^'itll  reference  to  the 
efficacy  of  any  treatment,  however,  he  advised  the  removal  of  the  tartar 
as  an  indisjieiisable  jireliminary.  The  jioints  of  diagnosis  differentiating 
between  this  condition  and  the  former,  that  of  gingivitis,  however 
sev^ere,  were  also  clearly  recognized  and   noted. 

Following  ^lagitot's  able  paper  was  one  by  Serran  in  1880,  in  which 
the  author  took  exce})tion  to  certain  of  Magitot's  views,  as  well  as  to  the 
term  by  which  the  latter  proposed  to  designate  the  disease.  He  recog- 
nized, however,  that  the  disease  was  most  common  in  middle  life  and 
occurred  principally  among  the  gouty,  the  diabetic,  and  the  albuminuric. 
He  believed  that  the  primary  manifestation  was  a  local  congestion  of 
the  gums,  followed  by  an  exudation  into  the  peridental  membrane  which 
destroyed  its  vitality  and  led  to  the  formation  of  pus  and  all  the  other 
symptoms  and  pathological  conditions  characteristic  of  the  disease.  A 
commission  composed  of  MM.  Dej)res,  Delens,  and  Magitot  was  ap- 
pointed by  the  Societe  de  Chirurgie  to  consider  the  statements  of  Dr. 
Serran.  In  this  report'  they  denied  the  r/inc/iral  origin  of  the  dis- 
ease, and  stated  their  belief  that  the  periosteal  membrane  and  the 
cementnm  were  the  primary  anatomical  scat  of  the  lesion  ;  that  the 
succession  of  morbid  j)lienoniena  com})letely  precluded  the  idea  of  an 
initial  gingivitis ;  that  the  disease  begins  without  any  trace  of  conges- 
tion of  the  gums  ;  that  after  its  formation  the  pus  burrows  toward  the 
gingival  border,  which  it  detaches — without,  however,  for  a  time  de- 
stroying its  normal  aspect ;  that  only  after  considerable  augmentation 
of  the  flow  of  pus  and  the  loosening  of  the  teeth  do  the  gums  become 

'  Bvlletins  et  Memoirs  de  la  Societe  de  Chirurgie,  tome  vi.  p.  411. 


HISTORY.  495 

implicated ;  that  the  disease  has  nothing  in  common  with  the  hypothesis 
of  a  gingival  malady,  and  that  it  is  most  frequently  a  manifestation  of 
a  general  state,  or  a  diathesis. 

These  were  the  views  entertained  and  published  by  French  surgeons 
on  the  nature  of  "pyorrhea  alveolaris"  about  the  period  when  the 
disease  began  to  receive  consideration  from  American  dentists.  Though 
pyorrhea  alveolaris  had  long  been  recognized  in  the  United  States  and 
various  observations  regarding  its  pathology  and  treatment  had  been 
published,  it  was  not  until  Dr.  John  AV.  Riggs,  in  October,  1875,  read 
a  paper  before  the  American  Academy  of  Dental  Surgery,  entitled 
"  Suppurative  Inflammation  of  the  Gums  and  Absorption  of  the  Gums 
and  Alveolar  Processes,"  that  the  disease  began  to  attract  the  attention 
its  gravity  merited.  Notwithstanding  the  views  entertained  by  Magitdt 
and  others  regarding  the  constitutional  character  of  the  disease,  Dr. 
Riggs  in  his  communication  ^  emphatically  denied  that  the  disease  is  an 
affection  of  the  bone  or  of  the  gums,  or  that  it  is  hereditary  or  constitu- 
tional, but,  on  the  contrary,  that  it  is  the  roughened  teeth  themselves, 
in  consequence  of  the  accretions  from  whatever  source  derived,  which 
are  the  exciting  cause  of  the  inflammation ;  that  it  is  purely  local  in 
origin,  the  result  of  concretions  near  and  under  the  free  margins  of  the 
gums,  the  removal  of  which  even  in  the  third  stage  is  followed  by  cure. 

In  1877  Dr.  F.  H.  Rehwinkel  ^  entered  his  protest  against  the 
theory  of  the  local  origin  of  the  disease,  and  endeavored  to  prove  that 
it  not  only  may  but  does  exist  independently  of  foreign  deposit  and 
must  depend  on  other  than  merely  local  causes,  and  that  it  is  an 
hereditary  and  constitutional  disease. 

Dr.  L.  C.  IngersoU,  in  1881,  published  a  paper  entitled  "San- 
guinary Calculus,"  ^  in  which  it  was  stated  that  the  persistent  flow  and 
discharge  of  pus  along  the  side  of  the  tooth  was  caused  by  an  inflamma- 
tion and  ulceration  at  or  near  the  apex  of  the  root ;  as  a  result  of  which 
molecular  death  the  liquor  sanguinis  escaped  from  the  bloodvessels  into 
the  surrounding  tissues  and  became  disorganized,  the  lime  salts  crystal- 
lized on  the  surface  of  the  roots,  and  formed  the  deposit  which  from  its 
origin  he  designated  "  sanguinary  calculus."  This  deposition  he  re- 
garded as  entirely  distinct  from  salivary  calculus,  and  as  derived  from 
the  blood — the  result  of  inflammatory  action  and  not  its  cause.  In 
other  words,  he  held  that  pyorrhea  is  a  local  disease  but  beginning 
centrally ;  that  is,  at  or  near  the  apex  of  the  root. 

^  Pennsylvania  Journal  of  Dental  Science,  vol.  iii.  p.  99. 

^  Report  of  the  Committee  on  Pathology  and  Surgery,  Trans.  American  Dental  Asso- 
ciation, 1877,  p.  96. 

^  Ohio  State  Journal  of  Dental  Science,  vol.  i.  p.  189. 


496  PYORRHEA   ALVEOLA RIS. 

In  LS82,  Dr.  A.  WitzcU  irad  a  paper  ht't'ore  the  German  Society  of 
Dentists/  in  whieli  it  was  asserted  that  the  primary  patliolopeal  cliange 
was  an  inflammation  and  caries  of  the  alveolar  border  followed  by  a 
deposit  just  beneath  the  free  marjjins  of  the  gums,  which  became  re- 
tracted and  reverted.  The  entrance  of  micro-organisms  into  this  carious 
region  developed  ])ns  which  became  more  or  less  infectious.  In  consc- 
(juence  he  termed  the  disease  "  infectious  alveolitis."  He  regarded  the 
disease  as  a  ])riinavy  local  alveolitis,  having  no  constitutional  relations 
whatever,  a  nolecular  necrosis  of  the  alveoli  or  caries  of  the  dental 
sockets  ])roduced  by  septic  irritation  of  the  medulla  of  the  bone. 

In  1886,  Dr.  G.  V.  Black  prepared  for  publication  probably  the 
most  exhaustive  jiaper  in  print  in  the  United  States,  wherein  jnorrhea 
alveolaris  is  treated  as  a  local  disturbance."  Calcic  inflammation  and 
phagedenic  pericementitis  are  the  terms  he  employs  to  indicate  its  cha- 
racter. Though  he  believes  it  to  be  wholly  local,  he  thinks  a  serumal 
or  sanguinary  deposit  may  be  closely  allied  with  its  origin.  He  de- 
scribes it  as  a  destructive  inflammation  of  the  pericemental  membrane, 
distinct  from  other  iirflammations  of  this  tissue  though  having  many 
features  in  common  with  them.  The  disease,  he  estimates,  is  essentially 
one  of  the  peridental  meml)rane  rather  than  of  the  alveolus,  though  the 
destruction  of  these  two  structures  is  so  nearly  synchronous  that  it  is 
difficult  to  say  which  has  gone  first. 

In  1886,  Dr.  W.  J.  Reese  read  a  paper  before  the  Louisiana  State 
Dental  Association  on  "Uremia  and  Its  Effect  on  the  Teeth/"*  in  which 
the  chemical,  physiological,  and  pathological  relations  of  uric  acid  to  the 
general  nutrition  were  discussed.  In  this  communication  Dr.  Reese  ex- 
pressed the  opinion  that  the  inflammation  of  the  pericemental  membrane 
followed  by  suppuration  and  disorganization  w'hen  in  contact  with  the 
secretions  of  the  mouth,  is  caused  by  the  deposition  of  uric  acid  derived 
from  the  blood  ;  that  the  disease  should  be  termed  "  j)hagedena  peri- 
ccmcnti  ;"  that  "  pyorrhea  alveolaris"  is  a  misnomer.  He  also  stated 
that  wliile  the  to])hus  on  the  roots  of  the  teeth  is  the  usual  con- 
comitant of  uric  acid,  it  is  not  necessarily  so,  but  that  absorption  of 
the  pericemental  membrane  may  take  place  without  any  deposit. 
Though  a  local  treatment  was  advocated,  he  stated  that  without  sys- 
temic or  constitutional  treatment  the  return  of  the  trouble  may  be 
expected. 

Dr.  John  S.  Marshall,  in  1891,  expressed  his  conviction  that  pyor- 

'  Vierteljahresschrij't  filr  Zaknheilkuncle,  1882  ;  British  Journal  of  Denial  Science,  vol.  xxv. 
p.  153. 

-  "  Diseases  of  the  Peridental  Membrane  having  their  Beginning  at  the  Margin  pf 
the  (rum,"  American  System  of  Dentistry,  vol.  v.  p.  953. 

^  Dental  Cosmos,  vol,  xxv.  p.  550. 


TERMINOLOGY.  497 

rhea  has  a  constitutional  origin  and  is  closely  allied  to  the  rheumatic 
or  gouty  diathesis ;  "  that  the  deposition  of  the  concretions  upon  the 
roots  of  the  teeth  in  those  localities  not  easily  reached  by  the  saliva,  or 
in  which  the  presence  of  the  saliva  would  be  an  impossibility,  is  due 
to  the  causes  which  produce  the  chalky  formations  found  in  the  joints 
and  fibrous  tissues  of  gouty  and  rheumatic  individuals."^ 

The  writer,  in  a  series  of  papers  published  during  1892-94-95,^  pre- 
sented a  number  of  clinical  and  pathological  facts  which  in  their  totality 
it  was  believed  established  a  kinship  between  pyorrhea  alveolaris  or 
hematogenic  calcic  pericementitis  and  the  constitutional  state  familiarly 
known  as  the  gouty  or  uric  acid  diathesis. 

Recent  literature  by  American  writers  has  dealt  largely  with  the 
problem  of  the  etiology  of  the  disease  in  question  and  has  been  princi- 
pally concerned  in  determining  whether  it  is  of  constitutional  origin  or 
of  local  origin,  or  of  both.  Of  the  more  important  recent  writings  on 
the  subject  may  be  mentioned  those  of  Drs.  E.  T.  Darby,  H.  H.  Bur- 
chard,  G.  V.  Black,  M.  L.  Rhein,  E.  C.  Kirk,  James  Truman,  Junius 
E.  Cravens,  Louis  Jack,  R.  R.  Andrews,  and  R.  Ottolengui. 

Terminology. — No  disease  in  the  whole  domain  of  surgery  has 
received  so  many  and  such  diverse  names  as  the  one  under  consideration. 
Each  succeeding  title  was  an  attempt  at  the  production  of  a  comprehen- 
sive descriptive  designation  of  the  disease,  but  when  it  is  recognized 
that  the  essential  nature  of  the  pathological  processes  involved  is,  even 
now,  not  fully  made  out,  it  is  evident  that  the  many  names  simply 
represent  as  many  diverse  views  and  can  therefore  have  no  permanency, 
nor  do  they,  indeed,  deserve  any. 

The  following  is  a  fairly  complete  list  of  the  synonyms  of  the  dis- 
order :  Suppuration  conjointe ;  Pyorrhea  inter-alveolo-dentaire ;  Gingi- 
vitis expulsiva  ;  Osteo-periostiti-alveolo-dentaire  ;  Pyorrhea  alveolo  ; 
Cemento-periostitis  ;  Infectioso-alveolitis  ;  Pyorrhea  alveolaris  ;  Calcic 
inflammation  ;  Phagedenic  pericementitis  ;  Riggs'  disease  ;  Hemato- 
genic calcic  pericementitis  ;  Blennorrhea  alveolaris  ;  Gouty  pericemen- 
titis. 

Clinically  the  cases  in  which  these  phenomena  are  observed  may  be 
divided  into  two  classes  :  First,  those  in  which  the  disease  process 
begins  at  the  gum  margin.  The  second  class  begins  at  some  portion  of 
the  alveolus  between  the  unbroken  and  apparently  healthy  gum  margin 
and  the  apex  of  the  root,  the  pulp  of  the  tooth  being  alive.  These  two 
conditions  are  so  clearly  differentiated  from  one  another  that  each  re- 
quires a  separate  description.     Between  these  two  classes,  but  intimately 

^  "  The  Rheumatic  and  Gouty  Diathesis,  with  its  Manifestations  in  the  Peridental 
Membrane,"  Trans.  American  Medical  Association,  1891. 
^  International  Dental  Journal,  vols,  xiii.,  xv.  and  xvi. 
32 


4!!.^  PYORIUIKA    ALVEOLARIS. 

associated  witli  tlio  latti-r,  aro  to  ho  incliKlod  tlio  oasos  (lesorilxd  hv  Dr. 
G.  V.  IMack  '  a.s  "  pliagcdciiif  perioonu'iititis." 

Class  I.   Pyorrhea  Alveolaris  beginning  at  the  Gum 
Margin  (Ptyalogenic  Calcic  Pericementitis). 

The  first  class — tliose  cases  bctrinninir  not  at,  but  iinnicdiatoly  be- 
neath the  gum  margin — are  perhaps  the  most  common,  are  by  some 
erroneously  supposed  to  be  the  only  type  of  cases,  and  will  require 
dcscripti(tn  first,  as  their  causes,  progress,  prognosis,  and  treatment 
ditier  radically  from  those  of  the  second  elass. 

Causes  of  Class  I. — As  in  any  disease,  the  causes  of  pyorrhea 
alveolaris  grouped  as  Class  I.  may  be  divided  into  ]>redisposing  and 
exciting.  The  predisposing  causes  may  all  be  included  under  the  head 
of  disorders  causing  a  subacute  inflammation  of  the  gingivae.  General 
catarrhal  conditions;  small  but  irritating  deposits  upon  the  necks  of  the 
teeth,  as  the  accumulations  upon  the  teeth  of  smokers ;  fermenting 
deposits  of  food  ;  spirit-drinkers'  stomatitis,  mouth-l)reathers'  gingivitis; 
overcrowding  of  the  teeth,  mal-ocelusion,  and  non-occlusion.  The  pre- 
disposing causes  may  also  frequently  be  the  exciting  causes.  The  excit- 
ing causes  proper  are,  however,  subgingival  scaly  deposits  of  calculi. 

Clinical  History. — In  the  mouth  of  a  patient  of  one  of  the  above- 
mentioned  classes  there  will  be  noted  at  some  period  a  gingivitis — a 
swelling  of  the  gum  w'hich  does  not  extend  far  from  their  margins. 
It  is  noteworthy  that  in  these  cases,  as  in  the  succeeding  class,  it  is 
usual  to  find  the  disease  attack  teeth  which  are  comparatively  or  quite 
exempt  from  the  inroads  of  caries.  Soon  after  the  inci])iency  of  the 
disease  there  may  be  squeezed  from  beneath  the  gum  margins  a  detritus 
of  food  debris  and  inspissated  mucus.  At  a  later  stage  a  sharp  scaler 
passed  beneath  the  gum  margin  may  detach  a  flat  greenish  or  black  de- 
posit of  calculus.  Later,  the  gingiva?  are  seen  to  l)ecome  swollen  and  are 
gradually  detached  from  the  neck  of  the  tooth,  the  flattened  calculus  in- 
creases in  volume,  and  the  irritation  and  injection  of  the  gum  deepens. 
"  It  is  probaljle  that  these  deposits  have  their  origin  in  a  reaction  be- 
tween the  altered  mucous  secretion  of  the  gingival  glands  and  the  ])ro- 
ducts  of  lactic  fermentation,  their  calcic  salts  being  derived  from  the 
saliva."  ^  The  detachment  of  the  gum  does  not  become  marked  until 
these  dark  scaly  deposits  have  encroached  upon  the  margins  of  the 
alveolus.  Soon  thereafter,  or  indeed  before,  evidences  of  infection  are 
observed,  from  the  fact  that  pus  may  be  pressed  from  the  pockets.  The 
disease  progresses,  the  teeth  loosen,  and  ultimately  drop  out  or  are  re- 

*  American  System  of  DentiMry,  vol.  i. 

*  H.  H.  Burchard,  Dental  Cosmos,  October,  1895. 


PATHOLOGY  AND  MORBID  ANATOMY. 


499 


Fig.  462. 


moved  with  the  fingers,  the  injected  gum  remaining  as  a  flabby  mass 
and  all  evidences  of  dental  disease  ceasing  with  the  loss  of  the  teeth. 
The  process  may  involve  one,  two,  or  more  teeth  and  in  some  cases  an 
entire  denture.  The  origin  of  these  deposits  as  well  as  those  of  ordi- 
nary calculi  are  so  clearly  traceable  to  the  saliva  that  the  writer  has 
suggested  for  the  conditions  caused  by  them  the  name  of  jjtyalogenic 
calcic  'jpericementitis. 

Pathology  and  Morbid  Anatomy. — The  appended  figure,  semi- 
diagrammatic,  will  illustrate  clearly  the  nature  of  the  disease  process 
(Fig.  462).  It  represents  a  longitudinal  section  through  a  tooth 
and  its  alveolus,  with  the  vascular  supply  to  the  tissues.  The  peri- 
cementum and  alveolar  walls  for  some  distance  from  the  apex  of 
the  root  are  in  a  healthy  condition.  At  the  neck  of  the  tooth  are 
seen  two  deposits  of  calculi  (a,  a).  The  overlying  gum  (6,  h)  is 
seen  to  be  swollen  and  tumid  at  its  edges.  Immediately  below  the 
calculus,  where  it  encroaches  upon  the  pericementum,  the  latter  tissue 
and  also  a  portion  of  the  alveolar  periosteum  is  seen  to  have  under- 
gone necrotic  changes  (c?).  The  portion  of  alveolar  wall  uncovered 
by  jaeriosteum  is  in  process  of  dissolution.  In  the  pocket  beneath  the 
calculus  a  collection  of  pus  is  seen  (c,  c),  so  that  the  tissues  beyond 
the  calculus  are  involved  in  suppura- 
tive degeneration,  which  may  be  slow 
or  rapid  in  its  progress. 

The  diagnosis  is  by  sight  and  touch 
and  not  infrequently  by  odor,  as  par- 
ticularly in  unhygienic  mouths  an  offen- 
sive odor  attends  the  progress  of  the 
disease.  The  gums  are  tumid ;  from 
about  the  necks  of  the  teeth  pus  may 
be  pressed,  and  touch  demonstrates  the 
presence  of  flat,  dark,  and  firmly  ad- 
herent scaly  calculi. 

The  prognosis  is  favorable  at  even 
advanced  stages,  provided  certain  con- 
ditions may  be  obtained,  viz.  a  removal 
or  correction  of  the  predisposing  causes 
and  a  perfect  removal  of  the  exciting 
causes. 

Treatment. — The  treatment  is  based 
purely  upon  the  existing  conditions,  with  two  main  objects  in  view. 
The  first  is  to  remove  every  source  of  irritation ;  the  second,  to  procure 
surgical  rest  until  there  is  a  return  of  the  surrounding  tissues  to  a 
normal  condition. 


Ptyalogenic  calcic  pericementitis 
(Burchard). 


500 


I'Vnnn UK. I    ALVEOLA R IS. 


As  a  ^ciuTtil  nilr  tlio  first  step  of  the  operatiou  consists  in  a  careful 
and  tliorough  scaling  of  the  teeth.  It  is  essential  that  the  use  of  bulky 
scalers  be  avoided — first,    for  the   reason    that    they  rarely  reach    the 

deepest   j)ortions  of  the    deposits  ; 
*"''S-  -IG-'^-  second,  tliat  if  they  do,  they  cause 

more  or  less  laceration  of  the  gum, 
which  should  be  kept  as  free  from 
injury  as  possible.  Tlie  instru- 
ments employed  for  tliis  ])urpose 
by  a  majority  of  operators  arc  the 
set  known  as  Cushing's  scalers 
(Fig.  463).  Their  mode  of  appli- 
cation and  their  position  relative 
cushings scak-rs.  *»  the  root  arc  shown  in  Figs.  464, 

465.  No  instrument  with  a  draw 
cut  can  remove  these  deposits  with  the  same  thoroughness  as 
one  operated  with  a  push  cut.  With  proper  guarding  it  is 
improbable  that  these  instruments  should  do  harm  to  the 
vital  parts  beyond  the  calculus.  Great  care  should  be  exer- 
cised in  the  use  of  pushing  instruments  to  avoid  forcing  the 
dislodged  particles  into  the  deeper  tissues.  The  scaling  is  a 
tedious  operation,  but  one  which  should  be  persisted  in  until 
the  root  of  the  affected  tooth  is  absolutely  smooth.  The  scal- 
ing is  alternated  with  a  washing  out  of  the  pockets  with  3 
per  cent,  pyrozone  or  hydrogen  dioxid,  which  washes  out  the 
detached  particles  of  calculus  and  disinfects  the  parts.  "  When 
the  gums  are  tumid  and  interfere  notably  with  the  scaling  pro- 
cess, applications  are  made  of  a  solution  of  trichloracetic  acid 
1:10  upon  cotton  tents ;  this  checks  oozing,  shrinks  the  gum, 
giving  a  better  view  of  the  parts,  and  tends  to  soften  the  de- 
posits." '  "  It  not  infrequently  happens  that  the  teeth  have 
suffered  such  extensive  loss  of  their  retaining  structures  that 
the  operation  of  scaling  tends  to  still  further  loosen  them.  In 
these  cases  the  correction  of  mal-occlusion  and  splinting  the 
teeth  should  be  attended  to  before  ])roceeding  farther  with  the 
operation.  The  teeth  should  be  ligatured  to  their  fellows, 
and  the  excessive  occlusion  corrected  by  grinding  away  the 
points  of  contact  with  corundum  wheels  sufficiently  to  relieve 
the  teeth  of  strain  and  to  permit  the  fixing  of  a  metallic  splint 
by  means  of  which  the  teeth  may  be  held  firmly,  during  and  subsequent 
to  the  scaling  operation."  ^ 

Splints  for  these  cases  are  usually  swaged  metallic  caps  made  of 

*  E.  C.  Kirk.  ^  H.  H.  liurcluird,  International  Dental  Journal,  August  1895. 


PATHOLOGY  AND  MORBID  ANATOMY. 


501 


No.  31  metal,  gold  or  silver,  which  are  cemented  to  the  teeth  (Fig. 
-4  66).  When  the  teeth  have  suitable  forms,  a  succession  of  rings  sol- 
dered together  may  be  employed ;  in  other  oases  the  teeth  are  lashed 
together  by  means  of  fine  gold  wire.  For  temporary  use  No.  31  or  32 
annealed  brass  wire  may  be  used,  and  when  left  in  situ  for  weeks  or 
months  it  exerts  no  deleterious  effect.     In  fact,  it  appears  to  possess 

Fig.  464. 


Showing  the  manner  of  holding  an  instrument  for  detaching  calcareous  deposits  when  using  the 
pushing  motion.  The  third  finger  rests  on  the  edges  of  the  teeth,  allowing  freedom  of  the 
hand  to  make  rapid  and  effectual  movements  in  dislodging  the  calculi. 


antiseptic  properties  similar  to  those  attributed  to  copper  amalgam 
when  used  as  a  filling  material.  Or,  if  frequently  renewed,  floss  silk 
may  be  used.  Devices  for  this  purpose  are  as  numerous  as  designs 
for  bridge  work. 

Each  root  is  to  be  perfectly  scaled  before  proceeding  to  a  second 
tooth.  At  the  completion  of  the  scaling  the  pockets  are  freely  syringed 
out  with  pyrozone  3  per  cent.,  and  an  application  of  an  astringent  made: 
a    10    per  cent,  solution  of  zinc  chlorid,  20  per  cent,  solution   of  zinc 


502 


P  YORRHEA    A  L  VEOL  A  R  fS. 


iodid,  or  tr.  iodin.  U.  S.  P.  diluted  one-half  with  alcohol.     Prepara- 
tions (^f  aristol  and  the  officinal  tincture  of  iodin  are  also  used,  all  of 

which     subserve    the    desired    end,    to 
Fig.  466.  sterilize    the    parts    and    to    eonstringe 

the    dilated    vessels    of  the  jruni.     An 
antiseptic  and    astringent   mouth-wash 

Ft-;    4t:t; 


is  prescribed  which  the  patient  is  to 
use  several  times  daily.  The  follow- 
ing preparation  applied  on  a  small  roll 
or  tuft  of  cotton  wool  or  by  means  of 
a  soft  toothbrush  admirably  meets  the  conditions  : 


Showing  the  application  of  a  thin  flat 
instrument  to  the  labial  and  approxi- 
nial  surfaces  of  an  upper  bicuspid 
(pushing  motion). 


I^.  Zinci  chlorid.,  cryst., 
Aquae  menthae  pip., 
S.  Apply  locally  to  the  gums. 


fsiv.— M. 


As  early  in  the  treatment  as  possible  a  thorough  examination  should 
be  made  with  a  delicate  exploring  instrument,  so  that  any  calculi  which 
may  be  detected  may  be  removed. 

A  method  of  treatment  which  has  given  much  satisfaction  to  the 
Mriter  is  as  follows  :  First  tlK>roughly  cleanse  the  mouth  and  each 
particular  pocket  with  hydrogen  peroxid,  electrozoiie,  or  some  other 
equally  efficient  antiseptic.  Then  with  a  blunt  but  flexible  broach, 
gold  or  steel,  let  each  pocket  from  which  pus  has  been  issuing  be  very 
carefully  saturated  with  trichloracetic  acid  ;  this  is  repeated  each  visit 
if  pus  continues  to  flow.  Following  this,  the  pockets  and  gingival 
borders  or  margins  are  thoroughly  treated  with  tincture  of  iodin,  fol- 
lowed with  solution  of  hydronaphthol  and  alcohol.  If  the  gingivae, 
however,  should  be  tumefied,  an  application  of  carbolic  acid  will  prove 
advantageous  : 

^i.  Hydronaphthol,  Sij  ; 

Alcohol,  5iv. 

This  must  be  used  with  caution,  for  it  is  of  sufficient  strength  to  give 
the  patient  much  discomfort  if  brought  in  contact  with  lips  and  tongue. 
The  frequency  of  the  visits  and  applications  must  depend  upon  the  viru- 


GOUTY  PERICEMENTITIS.  503 

lence  of  the  disease.     A  wash  for  the  patient's  daily  use  made  from  the 
following  formula  will  be  of  great  service  : 

^.  Hydronaphtholj  gr.  x; 

Glycerol,  §j ; 

Alcohol,  |ij ; 

Aquae  dest.,  |ij. 

The  use  of  hydronaphthol  iu  pyorrhea  alveolaris   was  suggested  by 
Prof.  James  Truman. 

The  loss  of  alveolar  walls  is  permanent ;  the  utmost  the  operator 
can  hope  in  extreme  cases  is  a  reorganization  of  the  tissues  which 
have  been  softened  as  a  consequence  of  the  inflammatory  action. 

Class  IE.   Pyorrhea  Alveolaris  of  Constitutional  Origin — 
Gouty  Pericementitis. 

The  second  class  of  pyorrhea  cases — those  in  which  local  therapeusis 
has  not  been  attended  with  permanent  good  results — are  usually  chronic, 
extending  over  a  variable  period  of  time,  owing  to  the  fact  that  they  are 
but  the  local  expression  of  constitutional  states.  Of  these  many  forms  of 
pyorrhea,  one  is  particularly  persistent,  terminating  only,  unless  proj)- 
erly  treated,  with  the  exfoliation  of  the  affected  teeth.  This  particular 
form,  which  has  been  the  subject  of  much  discussion  during  the  past 
twenty-five  years,  the  writer  believes  to  have  been  shown  to  be  but  a 
local  expression  of  the  gouty  diathesis  and  directly  dependent  on  the 
deposition  of  imperfectly  oxidized  waste  products  of  the  nutritional  process 
such  as  uric  acid  and  urates,  together  with  calcium  salts  in  the  perice- 
mental membrane ;  it  is  probable  that  allied  and  closely  related  compounds, 
such  as  the  xanthin  or  alloxuric  bases  (xanthin,  guanin,  and  adenin),  may 
also  be  present  in  small  quantities.  Indeed,  as  the  gouty  diathesis  is  largely 
dependent  on  a  faulty  metabolism  of  proteid  compounds  and  an  imperfect 
elimination  of  nitrogen-holding  derivatives,  it  is  quite  possible,  though  not 
proved,  that  any  or  all  of  the  above-mentioned  derivatives  may  be  present 
in  any  pathological  deposition.  Inasmuch,  however,  as  the  amounts  of 
these  compounds  are  small,  uric  acid  and  uratic  salts  must  be  regarded 
as  the  chief  of  the  specific  irritants.  As  the  origin  of  the  salts  is  from 
the  blood,  the  writer  suggested  the  term  hematogenic  calcic  pericementitis. 
Subsequently  Dr.  E.  T.  Darby  suggested  the  happily  applicable  term 
gouty  pericementitis. 

Clinical  History. — It  is  noted  that  many  patients  who  have  mag- 
nificent dentures  almost  exempt  from  caries,  at  a  period  about  middle 
life  begin  to  have  a  loosening  of  the  teeth  which  if  unchecked  leads 
to  the  loss  of  the  entire  denture.  The  disease  may  be  observed  at 
any  stage  from  a  slight  loosening  to  impending  exfoliation.  An  exam- 
ination of  many  cases  will  show  that  although  they  present  apparently 


004  PYORRHEA   ALVEOLARJS. 

diverse  conditions,  yet  beneath  these  differences  tliere  is  a  strikiiiir  nni- 
fonnity,  ]>articiilarly  as  to  the  fiimily  liistory  of  such  patients. 

A  coinplctc  and  accurate  study  of  the  succession  of  symptoms  ^vhich 
a  ty|)ical  i-asc  of  irouty  pericementitis  presents  from  its  iMcc|)ti<tn  to  its 
termination  is  rendered  difficult,  o\viu«r  to  the  lack  of  extended  ol)scrva- 
tiou  of  the  disease  throujjhout  the  entire  period  of  its  evolution  and  dis- 
solution. This  is  especially  true  of  this  disease  in  its  earlier  stages. 
Nevertheless  from  an  attentive  study  of  a  larire  nundx-r  of  individual 
cases  in  various  stages  of  development  it  is  believed  that  a  fairly  cor- 
rect picture  can  be  deduced. 

First  as  to  the  teeth  themselves ;  as  stated,  they  are  almost  exempt 
from  recent  caries.  The  teeth  frequently  exhibit  a  tendency  to  me- 
chanical abrasion  upon  their  cutting  edges  or  labial  surfaces.  If  the 
patient  be  of  a  sanguine  temperament,  or  this  temperament  combined 
with  the  bilious,  the  tendency  to  erosion  is  much  more  pronounced. 
It  must  be  appreciated  that  this  destruction  of  tooth  tissue  has  nothing 
in  common  with  ordinary  dental  decay  or  with  the  results  of  friction 
in  mastication. 

In  nearly  all  cases,  should  excavation  of  cavities  in  the  teeth  become 
necessary,  or  sections  of  lost  teeth  be  examined,  it  will  be  found  that  the 
]>ulp  has  receded,  i.  e.  has  suffered  a  continued  stimulation  of  its  fimc- 
tional  activity  to  the  extent  almost  of  obliteration. 

The  patient  may  consult  the  operator  as  to  the  causes  of  repeated 
attacks  of  dental  neuralgia,  or  the  reason  of  consultation  may  be  the 
alteration  of  position  of  one  or  more  teeth.  An  examination  of  the 
organs,  however,  reveals  no  evident  cause  for  either  the  neuralgia  or  the 
displacement. 

If  the  malposed  tooth  be  kept  under  observation  it  will  usually  be 
seen  to  become  elevated,  loosen,  and  finally  drop  out.  Other  teeth 
become  affected  in  a  similar  manner.  Dr.  Burchard  has  classified  the 
course  of  ])yorrhea  as  in  three  stages,  as  follows  :  "  First,  tooth  indura- 
tion ;  second,  erosion  or  chemical  solution  of  the  crowns  of  the  teeth; 
third,  a  loss  of  the  retaining  structures  of  the  teeth.  Pathologically 
stated,  there  is  first  a  stimulative  stage;  second,  an  irritative,  charac- 
terized by  altered  secretion  (erosion) ;  third,  the  necrotic." 

The  altered  secretion  pertains  to  the  labial  glands  largely,  and  the 
necrosis  to  the  pericemental  membrane  and  the  apical  end  of  the  root 
or  that  portion  which  has  been  denuded  of  the  membrane  ;  while  the 
alveolar  process  never,  in  the  writer's  judgment,  undergoes  any  change 
except  that  of  absorption  and  atrophy. 

By  far  the  greater  number  of  cases  present  themselves  when  the 
disease  has  made  marked  advance  about  one  or  several  teeth  and  their 
immediate  loss  is  threatened. 


GOUTY  PERICEMENTITIS.  505 

Assuming  that  the  gouty  diathesis  however  well  or  poorly  developed 
may  be  a  predisposing  cause,  and  the  deposition  of  some  characteristic 
specific  gouty  material  from  the  blood  into  the  pericemental  tissues  the 
immediate  or  exciting  cause,  we  have  an  explanation  for  the  irritation 
and  necrosis  of  the  alveolo-cemental  membrane,  which  even  in  its  early 
stages  is  easily  recognizable.  Coexistent  with  the  pericemental  hyper- 
emia there  is  more  or  less  redness  and  turgescence  of  the  gums,  accom- 
panied by  a  sense  of  tenderness,  soreness,  and  in  many  cases  neuralgic 
pain,  which  latter  symptom  frequently  precedes  all  other  symptoms. 
In  individuals  already  suffering  from  pyorrhea,  the  early  irritative 
stage  of  the  disorder  may  be  frequently  observed  in  teeth  previously 
free  from  all  signs  of  the  disease.  In  nearly  all  such  instances  the  focus 
of  the  diseased  action  is  confined  almost  exclusively  to  the  region  toward 
the  apical  extremity  of  the  root  without  there  being  the  slightest  evi- 
dence of  peripheral  local  gingivitis.  Too  much  stress  cannot  be  placed 
on  this  fact,  as  it  unquestionably  marks  the  incipiency  of  the  disease  and 
is  one  of  the  early  diagnostic  symptoms. 

Somewhere  near  the  apex  of  the  root  a  distinct  swelling  occurs  simu- 
lating an  acute  apical  abscess.  The  tooth  is  sensitive  upon  percussion, 
but  less  so  than  when  affected  by  purulent  apical  pericementitis  ;  more- 
over by  isolating  the  tooth  it  is  found  to  respond  to  applications  of 
cold,  proving  that  its  pulp  is  alive.  A  bistoury  passed  into  the  swell- 
ing is  followed  by  an  escape  of  blood,  and  usually  by  a  glairy  purulent 
discharge  also,  although  not  always.  In  some  cases  a  probe  passed  into 
the  opening  may  show  an  absence  of  alveolar  process  at  that  point,  and 
by  a  roughness  reveal  the  presence  of  a  deposit  uj)on  the  root  of  the 
tooth. 

The  teeth  so  affected  usually  present  an  appreciable  elevation  or 
protrusion  from  their  alveoli  in  consequence  of  the  enlarged  or  thick- 
ened and  congested  pericemental  membrane.  Should  this  congestion 
be  permitted  to  continue,  the  inflammatory  stage  in  consequence  of  the 
continued  presence  of  the  irritating  deposit  will  supervene,  with  its  con- 
comitant symptoms,  heat,  pain,  swelling,  and  marked  impairment  and  in 
some  instances  total  arrest  of  the  functions  of  the  tissues  involved. 

Inflammation  once  established  will  eventuate  in  localized  suppura- 
tion with  the  abatement  of  the  acute  symptoms.  The  location  of  the 
suppurative  process,  if  the  case  be  seen  and  recognized  early,  will  bf- 
found  in  the  large  majority  of  cases  to  be  near  the  apical  extremity  of 
the  root.  As  a  rule,  the  pus  takes  the  line  of  least  resistance  and  bur- 
rows directly  along  the  side  of  the  root  and  opens  externally  at  the 
gingival  border.  Occasionally  the  line  of  least  resistance  is  toward 
the  labial  surface,  with  the  discharge  of  pus  on  the  gum  opposite  the 
end  of  the  root,    thereby  establishing  a  fictitious  opening  simulating 


506  PYORRHEA   ALVEOLARIS. 

the  condition  observed  in  an  acute  alveolar  abscess ;  tlicse  cases,  liow- 
ever,  are  very  limited  in  miinber. 

Once  established,  these  conditions  of  increased  vascularity,  tnmclac- 
tion  of"  the  iiunis,  and  persistent  disehartje  of"  |)ns  may  continne  for 
months  or  vears  ;  the  rapidity  with  which  the  disease  j)roi2:resses  and 
the  extent  to  which  the  lesions  develoj)  will  l)e  directly  dei)endent  npon 
tiie  state  of  the  pMieral  nutrition  and  habits  of  the  individual. 

As  a  result  of  tlie  continued  irritation  in(hieed  by  the  deposit,  the 
inHammatiou  extends,  the  disturbed  relation  between  blood  and  sur- 
ronndintj:;  tissues  increases,  and  the  <rums  become  flaccid,  spong;y, 
altered  in  color,  and  lial)le  to  hemorrhafjic  discharixes.  As>ociated  with 
the  congested  and  thickened  condition  of  the  pericemental  membrane 
there  is  a  o:radnal  softeninsi;  and  absorption  of  the  alveolar  process,  which 
may  advance  to  such  an  extent  as  to  almost  or  in  some  cases  quite 
expose  the  root  thron<!:hont  its  entire  extent.  The  tooth  thus  freed  from 
its  retentive  structures  becomes  loose,  is  freely  movable  in  its  enlarged 
and  partially  destroyed  socket,  is  extremely  liable  to  dislodgment  by 
slight  mechanical  means,  or  if  by  care  these  arc  avoided  it  will  within 
a  limited  time  be  exfoliated  in  consequence  of  the  final  and  complete 
destruction  of  all  its  retaining  structures.  With  this  final  result  the 
progress  of  the  disease  is  arrested.  The  alveolar  socket  being  freely 
opened,  the  partially  dead  and  decomposing  tissues  are  removed  and 
the  remaining  structures  gradually  restored  to  a  normally  healthy  con- 
dition by  the  usual  processes  of  repair. 

When  once  estal)lished,  pyorrhea  alveolaris  does  not  confine  itself 
U)  any  one  tooth,  but  may  extend  to  adjoining  teeth  or  make  its  a})pear- 
ance  in  rapid  succession  in  widely  separated  regions  of  the  mouth  in 
the  lower  as  well  as  the  up])er  jaws  until  the  wdiole  denture  becomes 
involved,  with  an  eventual  exfoliation  of  all  the  teeth  and  a  complete 
resorption  of  the  alveolar  process.  When  these  exfoliated  teeth  are 
examined  there  will  be  found  at  some  point  of  the  root  surface, 
almost  always  near  the  apex,  an  incrustation  of  a  dark,  rough  cal- 
culus, or  it  may  be  several  of  them,  all  minute.  The  origin  of  the 
dejiosits  being  clearly  not  from  the  saliva,  which  is  the  source  of  the 
calculi  in  the  disease  described  under  the  head  of  Class  I.,  it  has  been 
called  serumal  or  sanguinary  calculus  (Ingersoll,  Black) ;  the  writer  has 
suggested  as  the  name  of  the  disease  caused  by  such  deposits,  hemato- 
genic calcic  pericementitis. 

These  assumed  gouty  deposits  led  the  writer  into  an  investigation 
as  to  the  family  history  of  patients  affected  by  this  disease.  Almost 
without  exception  these  individuals  have  been  shown  to  be  either  the 
victims  of  some  j)hase  or  form  of  gout,  of  alleged  rheumatism  or  of 
rheumatoid  arthritis  (rheumatic  gout),  or  to  have  a  clear  family  his- 


«      GOUTY  PERICEMENTITIS.  507 

tory  of  one  of  these  disorders.  Careful  investigation  by  several  other 
observers  has  brought  to  light  similar  testimony,  particularly  within 
the  past  three  years  (Kirk,  Darby,  Burchard,  Jack,  and  others). 

It  had  been  noted  by  succeeding  generations  of  practitioners  that  the 
therapeutic  resources  (local)  of  dentistry  were  insufficient  to  either  check 
or  cure  the  disease  condition.  All  local  means  of  treatment  having 
been  exhausted  and  shown  to  be  of  little  or  no  avail,  there  was  a  natural 
inquiry  into  the  exact  nature  of  the  predisposing  and  exciting  causes  of 
the  malady,  so  that  the  therapeusis  might  be  placed  upon  a  rational  basis. 

No  purely  local  causes  having  been  found  sufficient  to  account  for 
the  dental  condition,  all  constitutional  states  which  were  known  to 
affect  the  teeth  or  their  alveoli  were  examined  and  compared  with  the 
phenomena  of  the  dental  disorder.  While  it  was  and  is  found  that 
several  constitutional  conditions  do  predispose  to  pyorrhea  alveolaris,  a 
flow  of  pus  from  a  tooth  socket,  and  most  of  these  conditions  may  be 
included  under  the  heading  of  diseases  of  sub-oxidation,  none  of  them 
was  found  to  cause  a  disease  having  the  precise  clinical  phenomena 
noted  in  connection  with  the  one  under  discussion.  By  a  process  of 
exclusion,  and  finally  by  direct  clinical  and  experimental  evidence,  the 
field  of  inquiry  was  narrowed  down  to  the  conditions  which  clinical 
medicine  has  included  under  the  heading  of  the  disorders  of  the  gouty 
diathesis. 

In  order  to  clearly  comprehend  the  connection  of  the  general  condi- 
tion with  the  local  disease  it  is  necessary  to  examine  the  essential,  the 
intimate,  nature  of  gout  and  its  manifold  manifestations.  Much  con- 
fusion has  arisen  in  the  discussion  of  this  subject  due  to  the  lack  of 
agreement  of  observers  as  to  what  constitutes  gout,  many  apparently  as- 
suming that  gout  is  necessarily  and  inseparably  connected  with  an  acute 
attack  affecting  the  metatarso-phalangeal  articulation  (the  great  toe). 

Pathology  of  the  Constitutional  Morbid  Condition. — Pyorrhea 
alveolaris  regarded  as  a  local  manifestation  of  the  gouty  diathesis  is 
the  result  of  a  deposition  of  uratic  salts  in  the  pericemental  mem- 
brane :  these,  acting  as  a  local  irritant,  excite  a  specific  inflammation ; 
while,  as  in  other  manifestations,  the  deposition  of  the  gouty  material 
is  determined  by  an  abnormal  condition  of  the  membrane,  a  condition 
of  impaired  vitality,  the  result  of  some  mechanical  or  other  irritation, 
which  predisposes  it  to  the  infiltration. 

As  no  special  manifestation  of  the  gouty  diathesis  can  be  intelligently 
understood  without  reference  to  its  constitutional  relations,  it  will  not  be 
out  of  place  to  briefly  consider  the  phenomena  presented  by — (1)  The 
gouty  diathesis  as  a  constitutional  malady ;  (2)  The  special  manifesta- 
tion here  under  consideration  as  a  molecular  necrosis  of  the  perice- 
mental membrane,  or  pyorrhea  alveolaris. 


508  PYORRHEA    ALVEOLARTS.      » 

The  (/ontii  (lidtlicsi.^,  in  the  j^tMicral  ncccptatioii  of  the  term,  is  :i  con- 
stilutioiial  nuiliuly  wliicli  inanif'csts  itself  under  a  <;Teat  variety  of  forms 
in  (litferent  individuals.  It  is  eliaraeterized  l)y  an  excess  of  uric  acid 
and  its  eono-eners  in  the  blood,  due  either  to  increased  production, 
throut2:h  impaired  or  imperfect  assinulation  of  nitrojrcnons  food,  or  to 
imjH'rfeet  elimination  of  the  normal  amount  of  urates  by  the  kidneys. 
In  either  event  there  is  a  disturbance  of  the  normal  relations  between 
uric  acid  production  and  the  general  nutritional  ])rocess.  The  protean 
forms  under  which  the  diathesis  manifests  itself  will  vary  in  accord- 
ance with  the  type  of  constitution  and  with  the  peculiarities  of  organi- 
zation and  the  dejifK^e  of  vitality  of  individual  organs  and  tissues.  The 
lesions  or  p;itholo^M<'al  states  observed  are  believed  to  be  caused  by  the 
deposition  into  thb  tissues,  from  the  blood,  of  urate  of  sodium.  This 
diathesis  is  undeniably  hereditary,  as  its  presence  is  detectidjle  in  one 
form  or  another  in  fully  75  i)er  cent,  of  all  cases  in  two  and  even  three 
generations.  The  diathesis  can  also  be  acquired  by  individuals  who  are 
subjected  to  the  causes  which  rendered  the  diathesis  hereditary.  The 
age  at  which  the  local  expressions  manifest  themselves  lies  between  the 
thirty-fifth  and  fiftieth  }ears,  at  a  time  when  growth  has  ceased  and  the 
food  supply  is  required  only  for  tissue  repair  and  heat  production.  It 
is  most  common  among  those  who  lead  sedentary  lives,  who  indulge  in 
an  excess  of  nitrogenous  food  beyond  the  capacity  of  the  individual  to 
perfectlv  oxidize,  and  those  who  consume  excessive  amounts  of  fer- 
mented and  malted  beverages  and  the  heavier  wines. 

The  immediate  cause  of  all  gouty  expressions  appears  to  be  the  pres- 
ence of  urates  in  the  blood.  The  amount  normally  present  is  so  slight 
that  it  is  almost  non-detectable  by  ordinary  chemical  methods.  It  was 
shown  l)y  Dr.  Garrod  that  in  gouty  conditions  the  amount  was  increased 
to  as  much  as  0.175  per  1000  parts,  and  that  this  apparently  small 
quantity  was  quite  sufficient  to  act  as  the  irritating  cause  of  gout — a 
fact  corroborated  by  other  observers. 

The  various  theories  which  have  been  advocated  from  time  to  time 
in  explanation  of  this  uric  acid  increase  in  the  blood  plasma  are  unsatis- 
factory and  contradictory  ;  whether  it  is  the  result  of  imperfect  elimina- 
tion or  of  increased  production  through  excess  of  nitrogenous  foods  it 
is  difficult  to  state  positively  in  the  i)resent  state  of  pathology.  It  is 
quite  probable  that  the  diathesis  is  a  neurosis  which  affects  simultane- 
ously the  assimilative  as  well  as  the  excretory  functions  of  the  body. 
Whatever  the  explanation  may  be  as  to  the  accumulation  of  urates, 
their  presence  in  the  blood  is  generally  admitted  to  be  the  immediate 
cause  of  any  gouty  manifestation.  Dr.  Dyce  Duckworth  states  that  "  No 
conception  of  this  malady  is  ])ossible  which  should  exclude  from  its 
purview  the  part  played  in  it  ])y  uric  acid;"    "The  most  unequivocal 


GOUTY  PERICEMENTITIS.  509 

evidence  of  true  gouty  disease  is  that  derived  from  the  presence  of 
uratic  salts  in  the  tissues."  The  immediate  cause  for  the  deposition  of 
urates  in  individual  tissues  is  to  be  sought  for  in  a  special  vulnerability 
of  the  tissues,  a  loss  of  vitality,  the  result  of  mechanical,  chemical,  or 
vital  influences.  The  views  of  Ebstein  concerning  the  deposition  of 
uratic  salts  have  found  general  acceptance.  He  has  apparently  demon- 
strated that,  in  all  connective  tissues,  previous  to  the  deposition  there  is 
a  primary  necrosis  of  tissue  elements  without  which  the  crystallization 
could  not  take  place ;  that  this  disturbance  of  tissue  vitality  is  the 
predisposing  factor  and  the  crystallization  the  exciting  factor  of  gouty 
changes.  The  blood  plasma  transuding  through  the  walls  of  the  capil- 
lary vessels  carries  with  it  urate  of  sodium  in  solution ;  in  the  partially 
devitalized  tissue  inspissation  occurs  and  in  consequence  crystallization. 

The  urate  of  sodium  as  it  accumulates  acts  as  a  specific  irritant  to 
the  tissue,  giving  rise  to  a  variety  of  phenomena  in  accordance  with  the 
character  of  the  tissue  involved.  The  gouty  manifestations  may  be 
either  acute  or  chronic.  In  the  acute  forms  the  signs  and  symptoms 
are  those  of  an  acute  specific  inflammation  of  a  joint,  usually  that  of  the 
great  toe.  Clinical  study  of  pyorrhea  cases  strongly  indicates  that  the 
disease  frequently  attacks  the  dento-alveolar  articulation  before  other 
articulations  in  point  of  time.  The  local  symptoms,  pain,  heat,  tume- 
faction are  associated  with  marked  constitutional  reactions,  disordered 
digestion,  and  numerous  evidences  of  general  disturbance  of  nutrition. 
The  duration  of  the  attack  may  be  from  a  few  days  to  several  weeks. 
Repeated  attacks  lead  to  an  impairment  of  the  functi(ms  of  the  joint 
and  a  permanent  alteration  of  its  structure. 

In  the  chronic  forms  the  symptoms  are  more  widely  distributed  and 
their  intensity  is  less  pronounced  according  to  the  tissues  involved. 
The  various  manifestations  may  be  classified  as  follows  : 

Articular  gout,  in  which  the  deposit  occurs  in  joints. 

Tegumentary  gout,  in  which  the  deposit  takes  place  in  the  skin  and 
mucous  membranes.  Disease  of  the  skin,  such  as  eczema  and  psoriasis, 
and  catarrhal  affections  of  the  mucous  membranes,  such  as  pharyngitis, 
chronic  bronchitis,  gastric  and  intestinal  catarrhs,  have  long  been 
recognized  as  expressions  of  gout. 

Visceral  gout,  in  which  the  deposit  occurs  in  the  viscera,  such  as  the 
lungs,  heart,  bloodvessels,  spleen,  liyer,  kidneys,  i.  e.  giving  rise  to 
various  diseased  conditions  or  giving  a  peculiar  cast  to  disease  already 
established. 

Nervous  gout,  in  which  the  nervous  tissue  is  invaded,  manifesting 
itself  in  a  loss  of  mental  energy,  despondency,  irritability  of  temper, 
headaches,  neuralgia,  etc. 

The  limits  of  this  chapter  do  not  permit,  nor  is  it  desirable,  to  enter 


510  PYORRHEA  ALVEOLARIS. 

upon  a  (l('t:ul('(l  statement  of  the  symptoms  or  (Ha^rnostic  features  of 
these  various  pliases  of  the  gouty  diathesis  ;  sulliee  it  to  say  tliat,  under 
one  form  or  another,  they  are  frequently  jiresent  and  associated  with 
pvorrliea  alveolaris.  The  patlioh>gy  of  ])ericemental  inflammation  from 
uratic  deposition  unfolds  itself  logically  after  a  consideration  of  the 
diathesis  in  its  constitutional  aspects.  Bearing  in  mind  the  fact  that  the 
alveolo-ccmental  membrane  is  a  member  of  the  connective-tissue  group,  it 
is  not  at  all  surprising  that  it  also  should  become  the  seat  of  uratic  deposits. 

Pathology  of  the  Dental  Disease. — Unfortunately  the  anatomical 
relations  of  the  parts  and  other  factors  prevent  the  dental  observer  from 
collecting  a  complete  and  connected  series  of  observations  as  to  the  exact 
j)atho]ogy  of  the  disease,  so  that  our  deductions  in  this  direction  are 
necessarily  confined  to  a  basis  of  clinical  records. 

It  is  a  natural  inference  that  the  pericementum  is  the  part  attacked 
because  it  is  a  point  of  minor  resistance.  The  decreasing  volume  of 
pericementum  which  attends  the  progress  of  the  disease  in  these  cases 
is  necessarily  followed  by  a  contraction  of  the  caliber  of  the  blood- 
vessels. It  is  not  at  all  improbable  that,  as  a  consequence  of  the  general 
physical  condition,  atheromatous  changes  occur  in  the  pericemental 
bloodvessels  leading  to  their  occlusion.  If  it  be  necessary,  as  some 
pathologists  maintain,  that  a  death  of  cells  precede  the  deposits  in 
gout,  this  vascular  change  will  account  for  the  necrosis.  The  acid  re- 
action of  the  necrotic  area  causes  the  deposition  of  urates,  which  are 
insoluble  in  acids. 

The  deposit  is  the  source  of  an  irritation  which  in  most  cases  is 
followed  by  inflammation,  leading  to  inflammatory  degeneration  and 
probably  coagulation  necrosis  of  the  cellular  elements.  The  alveolar 
walls  melt  down  particle  by  particle,  the  pericementum  disappears,  the 
diseased  area  usually  becomes  infected  by  pyogenic  organisms,  and  the 
process  of  suppuration  is  an  additional  factor  leading  to  the  exfoliation 
of  the  teeth.  As  in  necrotic  areas  of  other  parts,  calcareous  deposits 
occur,  which  cover  and  almost  entirely  obscure  the  primary  deposit 
of  urates. 

The  condition  following  upon  a  deposit  at  the  lateral  aspect  of  a 
root,  in  its  pericementum,  is  shown  diagrammatically  in  Fig.  467.  At  a 
is  seen  the  calculus  embraced  by  a  territory  of  inflammatory  corpuscles, 
b.  The  pericementum  which  has  so  far  escaped  destruction  is  seen  at  c 
and  d,  that  at  d  nourished  by  the  anastomosing  vessels  from  the  alve- 
olar periosteum.  At  a  later  period  this  portion  of  pericementum  be- 
comes involved  in  tlie  degenerative  process,  and  pus  escapes  at  the  neck 
of  the  tooth.  In  other  cases  the  inflammatory  degeneration  extends 
from  the  deposit  to  the  overlying  gum,  which  is  perforated. 

It  is  conceivable  that  such  tissue  changes  should  exist  in  consequence 


G  0  VTY  PERICEMENTITIS. 


511 


of  injuries  sustained  during  ordinary  dental  manipulations,  the  careless 
use  of  the  teeth  in  biting  unyielding  substances,  or  even  in  the  unwise 
use  of  toothpicks,  brushes,  etc.  This  supposition  granted — and  of  its 
truth  there  appears  to  be  much  evidence,  for  the  disease  not  unfrequently 

Fig.  467. 


Hematogenic  calcic  pericementitis  (Burchard). 


develops  after  the  operation  of  wedging,  malleting,  etc. — it  is  reasonable 
to  believe  that  during  the  transudation  of  lymph  through  the  lymph 
channels  of  the  membrane,  cementum,  and  dentin  freighted  with  uratic 
salts,  deposition  and  crystallization  would  readily  take  place  in  the 
dento-alveolar  articulation  as  in  other  localities  of  the  body.  Not 
unfrequently  has  the  writer  recognized  pus-exuding  pockets  resulting 
solely  from  wedging  or  long-continued  malleting,  and  these  in  teeth  that 
previously  to  the  operation  were  as  free  from  any  appearance  of  either 
of  these  conditions  as  a  normal  tooth  could  be,  yet  an  idiosyncrasy 
or  predisposition  existed — the  exciting  cause  only  being  needed  to 
develop  it. 

With  this  deposit  and  accumulations  between  two  unyielding  bony 
surfaces  and  the  pressure  on  the  tissue  elements  in  consequence,  these 
salts  will  act  as  specific  irritants  and  engender  the  well-known  phe- 
nomena— pain,  congestion,  swelling,  exudation,  impaired  nutrition, 
tissue  disorganization,  the  formation  of  pus,  an  osteomyelitis  resulting 
in  the  absorption  of  the  alveolar  process,  and  finally  the  exfoliation 
of  the  teeth  characteristic  of  pyorrhea  alveolaris.  The  most  general 
seat  for  the  deposition  of  these  salts  is  toward  the  apex  of  the  root, 
where  the  texture  of  the  alveolo-cemental  membrane  is  less  firm  and 
compact,  and  more  bulky. 


512  i '  1  on  li  UK  A    A  L  \  'KOLA  RIS. 

The  supposition  that  jnorrlioa  alvoolaris  is  a  local  ox]>rossioTi  of  the 
p-ncral  diathesis  has  been  coiivcrtod  into  an  actuality  hy  the  demonstra- 
tion ot"  the  presence  of  uric  acid  and  its  allii'd  salts  in  the  incrustation 
foinid  on  the  roots  of  the  exfoliated  teeth.  The  chemical  analyses  made 
by  Prof.  Ernest  Congdon  of  the  Drexel  Institute  have  demonstrated 
the  j)resence  of  these  salts  beyond  question.'  All  of  the  established 
tests  for  uric  acid  were  employed  and  in  all  instances  crystals  of  uric 
acid,  sodium  urate,  and  calcium  phosphate  were  detected.  In  several 
instances  sodium  urates  were  most  abundant.  The  constant  presence 
of  these  salts  on  the  surfaces  of  the  roots — the  presence  of  which  is 
ascertained  by  proper  analyses  and  aided  vision — taken  in  connection 
with  the  fact  of  the  coexistence  of  gouty  disorders  in  other  tissues  justi- 
fies the  belief  that  the  form  of  pyorrhea  alvcolaris  here  described  is  a 
gouty  inflammation. 

The  derivation  of  the  salts  from  the  blood,  the  abundance  of  the 
calcium  salts  present,  and  the  ])rimary  location  of  the  inflammatory  pro- 
cess suggested  to  the  writer  the  term  hematogenic  calcic  pericementitis, 
though  it  is  admitted  that  the  single  v\y[{\wt  goidy  pericementitis  ^vo\\\d 
be  sufficiently  exjdanatory  and  descriptive.  The  succession  of  patho- 
logical states  is  readily  explained  and  justified  by  the  uratic  deposit. 
The  formation  of  pus  is  preceded  by  a  lowering  of  the  vitality  and  solu- 
tion of  the  pericemental  tissues.  This  having  been  accomplished,  the 
disintegrating  peridental  membrane  affords  a  favorable  nidus  for  the 
entrance  and  development  of  micro-organisms,  which  can  be  effected 
either  by  the  route  of  the  circulation  or  by  lesions  around  the  gum 
margins  which  give  opportunity  for  direct  infection  from  the  oral  fluids. 

When  organisms  once  gain  access  to  the  devitalized  tissue  they  mul- 
tiply with  great  rapidity,  and  in  so  doing  increase  the  disintegration  and 
solution  of  the  pericemental  membrane  with  the  formation  of  pus.  The 
specific  bacteria  which  have  been  demonstrated  to  be  j)resent  in  the  pus 
are  the  usual  forms — the  staphylococcus  pyogenes  aureus,  citreus,  and 
albus — which  though  capable  of  producing  pus  are  not  pathogenic  in  the 
sense  that  they  are  the  causative  agents  of  the  pericementitis  with  the 
formation  of  an  abscess.  The  purulent  fluid  burrows  in  the  line  of 
least  resistance,  which  in  the  majority  of  cases  is  toward  the  gum  mar- 
gin, whence  it  is  discharged  into  the  mouth,  the  fistulous  tract  thus 
established  constituting  the  well-known  pyorrheal  pocket. 

By  the  continued  irritation  of  the  uratic  deposition  and  the  co-opera- 
tion of  micro-organisms,  the  inflammatory  process  extends  until  the 
membrane  is  destroyed  to  such  an  extent  that  it  is  no  longer  capable 
of  nourishing  and  supporting  the  teeth. 

The  absorption  of  the  alveolar  process  is  in  accordance  with  the  laws 
'  See  IntemationaJ  Dental  Journal,  1894,  vol.  xv.  p.  1. 


GOUTY  PERICEMENTITIS.  513 

governing  bone  softening  and  absorption  in  general.  Any  constant 
pressure^  whether  from  inflammatory  exudation,  from  tumors,  or  from 
mechanical  or  infective  agencies  which  interfere  with  its  nutrition,  will 
lead  to  softening  and  absorption.  In  pericementitis  the  effusion  exerts 
a  pressure  in  both  directions,  toward  the  cementum  and  toward  the 
alveolar  walls ;  as  the  latter  are  spongy  in  character,  they  readily  yield 
to  the  absorptive  process.  Should  the  pressure  continue  indefinitely, 
or  until  the  alveolar  walls  become  denuded,  caries  or  necrosis  would 
inevitably  result.  Fortunately  this  termination  is  seldom  if  ever  seen  : 
the  most  careful  examination  of  the  alveolar  process  of  a  large  number 
of  patients  has  failed  to  show  any  alveolar  denudation ;  never,  in  the 
writer's  experience,  has  there  been  either  caries,  necrosis,  exfoliation, 
or  sequestration  of  bone.  Nor  could  there  be,  for  the  reason  that  the 
teeth  are  removed  either  naturally  or  artificially  before  complete  de- 
struction of  the  pericemental  membrane  has  been  accomplished.  With 
the  removal  of  the  teeth  and  its  associated  irritants  the  process  of  re- 
pair at  once  begins.  The  dead  and  dying  tissues  are  removed,  and 
fibrous  tissues  make  their  appearance,  organization  is  established,  and 
in  a  short  time  all  traces  of  abnormal  action  have  disappeared. 

Diagnosis. — The  diagnosis  of  pyorrhea  alveolaris  becomes  compara- 
tively easy  when  its  constitutional  relations,  its  mode  of  origin,  its  prin- 
cipal symptoms  and  pathology  are  borne  in  mind.  The  only  diseases 
with  which  it  might  be  (indeed,  has  been)  confounded  are,  first,  that  form 
of  pericementitis  which  has  been  designated  a  ptyalogenic  calcic  peri- 
cementitis ;  or,  second,  a  general  gingivitis  due  to  some  systemic  dis- 
turbance such  as  results  from  mercurial  ptyalism  or  syphilis ;  or,  third, 
a  severe  inflammation  of  continuity  due  to  some  local  disturbance  such 
as  an  ill-fitting  partial  denture  or  an  impacted  tooth,  possibly  a  third 
molar,  greatly  aggravated  by  some  morbid  systemic  condition.  These 
forms  of  pericementitis,  however,  present  many  points  of  contrast,  dif- 
fering in  their  clinical  history,  their  pathology,  symptomatology  and 
susceptibility  to  treatment.  In  the  hematogenic  forms  the  patient,  in 
the  great  majority  of  cases,  presents  some  other  manifestations  more  or 
less  pronounced,  of  the  gouty  or  rheumatic  diathesis. 

The  age  at  which  it  makes  its  appearance  is  usually  from  thirty-five 
to  fifty  years.  The  extreme  pain  frequently  present  around  the  roots  of 
one  or  more  teeth  in  the  early  stages,  and  before  there  is  any  evidence  of 
a  gingivitis ;  the  deviation  in  the  position,  and  the  apparent  or  actual 
elevation  of  the  tooth,  with  response  to  pressure ;  the  swelling  or  thick- 
ening of  the  pericemental  membrane ;  slight  tumefaction  of  the  gum 
with  deep  red  or  purplish  color  opposite  the  apical  end  of  the  root  of 
the  tooth  or  teeth  affected — and  all  of  this  before  the  appearance  of  pus  ; 
the  isolated  character  of  the  inflammation,  being  usually  confined  to  one 

33 


r,l4  PYORRHEA   ALVEOLARTS. 

tootli  111"  two  (II-  iiiorc  teeth  ill  widely  separated  re<ri(»iis  of"  the  mouth  ; 
the  exudation  and  disfliar«>e  of"  pus  ah)nt«:  hut  one  side  of  the  root, 
detaeliing  tlie  ^i'luj  at  the  neek,  thus  establisliing  a  sinus  or  pus  pocket; 
the  increase  of  the  flow  of  pus  from  the  interior  of  the  alveolus  under 
pressure ;  the  usually  limited  amount  of  calcic  deposition  as  contrasted 
with  the  ])tvalofr<*iii<'  form  ;  the  destruction  of  the  pericemental  mem- 
brane and  the  denudation  of"  the  eementiun  ;  the  absorjition  of  the 
alveolar  process;  the  loosening  and  exfoliation  of  the  teeth  indurated 
in  structuix*  and  changed  in  physical  appearance  are  the  main  ciiarac- 
teristics  of  the  disorder;  all  these  features  taken  in  thcMr  totality  so 
individualize  this  dif<ease  that  there  should  be  no  diiliculty  in  identi- 
fying it. 

In  the  ptydlof/rnic  form  almost  the  opposite  conditions  prevail.  As 
a  general  rule  there  is  no  evidence  that  there  is  any  constitutional  diath- 
esis of  which  it  might  be  an  expression.  The  age  at  which  it  presents 
itself  extends  from  the  eighteenth  year,  sometimes  earlier,  to  any  period 
in  later  years,  varying  in  its  virulence  with  the  varying  systemic  condi- 
tions and  food  habits  of  the  individual.  The  presence  of  a  calcic  depo- 
sition around  the  neck  of  the  tooth  is  often  most  abundant ;  the  primary 
gingivitis  occasioned  by  the  presence  of  this  mechanical  irritant  is  not 
confined  to  one  tooth  nor  to  isolated  regions  of  the  mouth;  the  subse- 
quent extension  (where  neglected)  and  infiltration  of  this  deposit  into 
and  beneath  the  pericemental  membrane;  the  localization  of  the  sup- 
puration in  the  early  stages  around  the  margin  of  the  gums  ;  the  de- 
layed loosening  of  the  teeth,  the  infrequent  loss  of  the  teeth  and  the 
susceptibility  to  successful  treatment  upon  the  removal  of  the  salivary 
deposit :  these  features  taken  together  fully  characterize  this  disease  and 
render  its  identification  easy. 

Contrasting  these  different  inflammatory  states  of  the  pericemental 
membrane  from  their  inception  to  their  termination,  it  becomes  evident 
that  distinct  yet  closely  allied  diseases  are  here  very  frequently  confused 
and  associated. 

Causation. — If  we  take  as  our  point  of  departure  the  postulate  that 
hematogenic  calcic  pyorrhea  alveolaris  is  but  a  special  manifestation  of 
the  gouty  diathesis,  we  should  expect  to  find  in  its  causation  the  same 
predisposing  and  exciting  agencies  operative  as  in  the  production  of  all 
other  manifestations  of  the  general  diathesis. 

Predisposing  Causes. — 1.  Heredity. — Among  the  predisposing 
causes  may  be  mentioned  heredity,  which  may  be  regarded  as  one  of 
the  most  important  factors  concerned  in  its  development.  The  writer 
feels  justified  in  asserting,  after  a  careful  investigation  into  the  family 
history  of  a  large  number  of  pyorrhea  patients  that  fully  90  per  cent, 
manifest  an  hereditary  tendency  to  this  disorder,  parents  and  grand-par- 


GOUTY  PERICEMENTITIS.  515 

ents  having  been  victims  of  the  same  disease.  Magitot  was  impressed 
with  the  significance  of  this  fact  years  ago,  and  stated  that  pyorrhea 
extended  through  two  and  three  generations  and  made  its  appearance 
at  corresponding  periods  of  life  and  in  similar  types  of  constitution. 

2.  Sex. — As  far  as  the  writer's  observations  extend,  sex  does  not 
appear  to  have  much  influence  in  the  production  of  pyorrhea,  women 
seeming  to  be  equally  alFected  with  men ;  eliminate  the  masculine 
dietary  habit  and  there  would  certainly  be  little  difference  in  the  pre- 
disposition to  the  disease. 

3.  Age. — The  age  at  which  pyorrhea  most  frequently  presents  itself 
is  the  period  of  middle  life — that  is,  between  the  ages  of  thirty  and 
fifty.  It  may  be,  though  it  is  very  rarely  seen  before  the  age  of 
thirty,  and  still  less  frequently  does  it  make  its  appearance  after  the 
age  of  sixty.  These  observations  are  corroborated  by  the  writings  of 
Magitot  and  others.  It  is  very  evident  that  pyorrhea  is  a  disease 
belonging  largely  to  a  period  of  life  when  growth  has  ceased  and  food 
is  required  only  for  tissue  repair  and  the  production  of  heat. 

4.  Diet. — A  careful  investigation  into  the  dietary  of  pyorrhea 
patients  will  disclose  the  fact  that  there  is  usually  a  consumption  of 
excessive  quantity  of  both  albuminous  and  starchy  foods,  much  more 
than  is  necessary  for  the  maintenance  of  the  nutrition,  and  more  than 
can  be  completely  oxidized  under  the  customary  or  existing  modes  of 
the  individual's  daily  life.  Coincidently  there  is  also  a  diminished 
consumption  of  water,  leading  to  an  imperfect  elimination  and  a  reten- 
tion of  the  products  of  this  incomplete  oxidation.  In  connection  with 
excessive  consumption  of  food  must  be  also  mentioned  as  co-operative 
factors  the  use  of  fermented  malt  liquors,  the  richer  claret  wines,  cham- 
pagnes, etc.  While  perhaps  no  one  class  of  foods  can  be  said  to  be 
especially  active  in  the  causation  of  pyorrhea  it  is  evident  that  exces- 
sive quantity  and  variety,  by  impairing  the  activity  of  the  digestive  appa- 
ratus and  giving  rise  to  a  large  quantity  of  nitrogenized  waste  products 
through  imperfect  oxidation,  would  materially  impair  and  lower  the  func- 
tional activity  of  the  system  generally  and  individual  tissues  in  particular. 

5.  Sedentary  Occupations. — Occupation  is  also  an  important  factor 
in  the  production  of  pyorrhea.  In  the  majority  of  instances  the  disease 
makes  its  appearance  in  those  who  are  obliged  to  lead  lives  of  enforced 
inactivity — school  teachers,  accountants,  etc.  All  sedentary  occupations 
which  necessitate  insufficient  personal  exercise  will  favor  the  imperfect 
oxidation  of  food  and  at  the  same  time  retard  the  elimination  of  waste 
products. 

Exciting  Causes. — The  immediate  agency  in  the  development  of 
pyorrhea  is  undoubtedly  the  deposition  in  the  pericemental  mem- 
brane of  waste  products    of   nitrogenous   metabolism    in  combination 


a  1  (')  P  VORRHEA   A L  VEOLA  RIS. 

\\\t\\  calfiimi  salt<  derived  fVoiii  the  l)l()(»d.  This  inorhilic  inatei'ial,  |)hiv- 
iii!^'  the  part  of  foroigii  hddies,  instates  and  excites  the  ineinhi'ane  to 
iiiihiiumatorv  aotivity  and  all  its  attendant  syni|)tonis.  Bnt  even  ad- 
mitting: thi.s  deposition,  there  must  be  some  predisposition  on  tlio  part 
of  the  membrane  which  makes  it  specially  lialde  ti»  siieh  deposition. 
This,  it  is  believed,  is  in  harmony  Avith  gonty  dejxtsition  in  all  otlier 
tissues  of  the  body  ;  it  is  to  be  fonnd  in  impaired  nutrition  and  lowered 
vitality  in  consequence  of  mechanical  strain  from  an  tiverc  lowdintj  of 
the  dental  arch,  contusions  or  injuries  consequent  upon  (he  usual  and 
ai>parently  unavoidable  dental  manipulations,  such  as  wedtjin^  and 
malletin<2:,  and  similar  ]>rocedures.  It  may  be  from  the  unskilful  em- 
])loyment  of  toothpicks,  toothbrushes,  etc. — though  these  latter  are  rare 
as  compared  with  other  acts  and  conditions  which  may  impair  the  nor- 
mal nutritional  condition  of  the  pericemental  membrane.  On  numer- 
ous occasions  where  the  predisposition  existed,  pyorrliea  has  devel- 
oped imiuediately  following  operations  upon  one  or  more  teeth.  Prof. 
Armand  Depres '  attril)utes  considerable  importance  to  the  overcrowded 
condition  of  the  dental  arch  as  a  predisposing  cause  in  the  develop- 
ment of  pyorrliea. 

Treatment. — The  treatment  of  gouty  pericementitis  resolves  itself 
into  both  local  and  constitutional. 

The  focal  treatment  is  to  be  directed  toward  removal  of  the  deposit 
and  the  control  and  the  suppression  of  the  inflammation  and  its  con- 
comitants, and  has  been  already  described  at  p.  511  in  connection  with 
the  study  of  ptyalogenic  calcic  pericementitis. 

( 'oii.sfitnfiona/  Treatment. — Whatever  the  predisposing  cause  may  be, 
the  immediate  or  exciting  cause  must  ever  be  borne  in  mind.  This,  it 
is  believed,  to  a  certain  extent  at  least  is  found  in  all  of  those  mechani- 
cal agencies,  so  well  known  to  the  dentist,  which  impair  or  lower  the 
TUitritional  level  of  the  pericementum,  thus  rendering  it  liable,  under 
certain  systemic  conditions,  to  a  deposition  of  uratic  salts.  The  ques- 
tion has  been  raised  as  to  why  the  membrane  of  one  or  more  teeth 
widely  separated  or  occupying  positions  on  opposite  sides  of  the  mouth, 
either  simultaneously  or  successively  becomes  the  seat  of  inflammation 
when  there  is  no  continuity  of  structure.  The  answer  to  this  must  be 
found  in  the  fact  that  impaired  nutrition  and  lowered  vitality  in  such 
structures  arc  due  in  the  majority  of  instances  to  mechanical  injury  of 
these.  Malocclusion  may  be  noted  as  a  fruitful  cause.  It  is  certainly 
within  the  experience  of  many  observant  dentists  that  jn'orrhea  has  not 
infrequently  developed  around  a  tooth  after  it  has  been  subjected  to  the 
necessary  mechanical  manipulations  incident  to  tooth  protection  and 
tooth  preservation. 

'  LcQons  de  Cliiiique  chirurgicule,  p.  9-056. 


GOUTY  PERICEMENTITIS.  517 

This  apparent  interference  with  the  nutrition  of  the  pericemental 
membrane  before  the  deposit  of  nric  acid  salts  takes  place  is  in  accord- 
ance with  what  is  believed  to  hold  true  for  other  manifestations  of  the 
gouty  diathesis.  As  a  prophylactic  measure,  therefore,  it  is  suggested 
that  whenever  there  is  the  slightest  tendency  to  pyorrhea,  or  any  other 
evidence  of  the  gouty  diathesis,  great  care  should  be  exercised  in  all 
dental  operations,  so  as  not  to  impair  the  nutrition  of  the  pericementum 
and  thus  establish  the  necessary  condition  for  the  uric  acid  deposit ;  also 
correction  of  all  cases  of  malocclusion— surgical  rest  as  far  as  possible. 

The  constitutional  treatment  which  has  been  indicated  as  efficient  in 
the  elimination  of  already  established  uric  acid  conditions  and  the 
restoration  of  a  faulty  nutrition  to  its  normal  state  may  with  great 
propriety  be  subdivided  into  hygienic  and  medicinal. 

The  hygienic  treatment  embraces  systematic  outdoor  exercise,  stimu- 
lation of  the  functional  activity  of  the  excretory  organs,  the  skin,  bowels, 
and  kidneys,  and  regulation  of  the  diet,  which  must  be  insisted  upon  in 
all  well-marked  cases,  and  especially  with  those  who,  for  various  reasons, 
lead  sedentary  and  inactive  lives.  Increased  muscular  activity  quickens 
circulation,  induces  deeper  and  fuller  respiratory  movements,  leads  to 
greater  vigor  in  the  general  nutritive  processes ;  waste  products  are 
removed  more  rapidly  and  the  combustion  of  the  food  increased  by  the 
absorption  of  a  large  amount  of  oxygen.  The  promotion  of  the  func- 
tional activity  of  the  eliminating  organs  is  well  recognized  as  an  import- 
ant hygienic  measure. 

The  perspiratory  and  sebaceous  glands  and  the  surface  capillary  circu- 
lation should  all  be  stimulated  by  sponging  of  the  skin  with  cold  water, 
vigorous  friction,  and  an  occasional  Turkish  bath,  where  such  treatment 
is  not  contraindicated  by  pulmonary  or  cardiac  aiFections.  Where  the 
liver  and  intestinal  glands  are  deficient  in  secretion  with  prevailing 
constipation,  they  should  be  stimulated  into  activity  by  the  use  of 
saline  waters  ;  most  excellent  for  this  purpose  being  the  Hunyadi  Janos 
and  Friedrichshalle.  These  are  especially  to  be  commended  because 
they  contain  a  large  percentage  of  sodium  and  magnesium  sulfates, 
both  of  which  are  useful  as  eliminating  agents. 

The  kidneys  should  be  assisted  in  the  excretion  of  waste  products 
by  the  free  use  of  negative  waters,  or  waters  in  which  the  saline  con- 
stituents are  present  in  minimum  quantity. 

Hot  or  distilled  water  in  sufficient  quantity  will  flush  the  alimentary 
canal,  increase  the  volume  of  blood,  and  stimulate  the  kidneys  to 
increased  activity.  It  is  not  only  a  common  observation,  but  rather 
a  remarkable  fact,  that  gouty  patients  are  inclined  to  drink  but  a  com- 
paratively small  quantity  of  water.  One  quart  of  hot  water  taken 
daily,  in  four  doses,  before  breakfast,  between  meals,  and  at  bedtime,  is 


:.l,^  PYORRHEA   ALVEOLARIS. 

con-iidercd  most  beneficial  in  its  effects  in  dissolving  and  ivnittvinir  irri- 
tatint;  products. 

The  most  iin])ortant  of  the  hygienic  measures  in  the  treatment  of 
all  goutv  manifestations  is  that  jicrtaining  to  the  diet.  As  uric  acid  is 
a  nitrogenized  compound  and  therefore  })resumably  one  of  the  imper- 
fi'ctlv  oxidized  products  of  albuminous  or  nitrogenized  food,  it  is  desir- 
able that  such  foods  be  excluded  as  far  as  possible  from  the  daily 
diet.  The  value  of  this  measure  is  admitted  and  insisted  upon  by  all 
clinicians. 

In  the  milder  manifestations  of  the  gouty  diathesis  such  as  we 
assume  exists  in  pyorrhea,  it  is  not  so  imperative  that  all  albuminous 
food  be  prohibited ;  nevertheless,  as  many  patients  are  consumers  of 
large  cpiantities  of  meat,  it  would  be  well  to  insist,  if  the  effort  to 
cure  is  to  be  made,  upon  the  total  exclusion  of  beef,  veal,  mutton,  and 
pork,  restricting  the  patient  in  albuminous  diet  to  white  meat  of  fowl, 
oysters,  fish,  and  lobsters.  Cheese,  beans,  and  the  white  of  eggs  are 
considered  objectionable,  and  in  many  cases  of  acute  gout  are  strictly 
prohibited  by  the  attending  physician. 

Experience  has  shown  that  various  alcoholic  drinks,  such  as  cham- 
])agnes,  port,  madeira,  and  sherry,  are  particularly  liable  to  give  rise  to 
the  accumulation  of  uric  acid.  The  lighter  wines,  as  claret  and  hock, 
are  not  considered  so  injurious.  The  malt  liquors,  beer,  ale,  and  ])orter, 
are  also  bv  many  clinicians  considered  in  their  influence  to  be  great 
offenders. 

The  medical  and  constitutional  treatment,  it  is  obvious,  should  be 
directed  toward  the  elimination  of  uric  acid  and  its  compounds.  For 
this  purpose  remedies  which  promote  the  formation  of  solui)le  and 
easily  diffusible  products  which  are  readily  eliminated  by  the  kidneys 
are  indicated.  From  time  immemorial  the  alkalies  and  alkaline  com- 
binations have  been  used  with  marked  success  in  the  management  of  all 
phases  of  the  gouty  diathesis. 

The  treatment  of  acute  gout  necessitates,  of  course,  different  or  more 
vigorous  remedies  than  those  required  for  the  subacute  or  chronic  forms 
with  which  the  dental  practitioner  will  be  called  upon  to  deal. 

Of  the  various  alkalies,  lithium  compounds — the  citrate  and  car- 
bonate— have  been  found  well  adapted  to  the  milder  phases  of  the 
disease.  The  writer  has  had  much  satisfaction  in  using,  on  the  sugges- 
tion of  Dr.  E.  C  Kirk,  the  tartarlithine  lithium  bitartrate,  also  alka- 
litliia  j)reparc(l  in  the  same  form  as  the  above-named  compounds — com- 
pressed tablets  containing  five  grains  each  ;  one  ttU)let  three  or  four 
times  daily  will  be  found  sufficient.  Should  the  use  of  these  lithia 
tablets  not  agree  with  the  patient,  the  potassium  carl)onate  in  ten-grain 
doses,  in  some  simple  bitter — gentian  or  quassia  water — three  or  four 


r 


GOUTY  PERICEMENTITIS.  519 

times  daily,  may  be  substituted.  A  valuable  adjunct  to  the  medicinal 
treatment  is  the  free  use  of  alkaline  waters,  which  assist  in  the  elimi- 
nation of  waste  products,  though  it  is  probable  that  the  good  eflPects 
attributed  to  these  are  largely  due  to  the  quantity  of  liquid  consumed. 

The  Saratoga,  Vichy,  alkaline  waters  of  Wisconsin,  the  Marienbad, 
Carlsbad,  Apollinaris,  etc.  have  all  been  found  efficacious.  Should 
the  patient  be  very  dyspeptic,  as  is  frequently  the  case,  remedies 
directed  to  the  digestive  viscera  are  of  course  indicated.  If  anemia  be 
a  concomitant,  iron  and  quinin  will  be  necessary.  A  combination 
which  has  been  found  of  great  value  in  improving  the  quality  of  the 
blood  is  one  of  iron  and  a  salt  of  potassium.  Bland's  pill,  consisting 
of  these  two  ingredients,  is  a  desirable  form  for  administration  ;  one 
three  times  a  day  will  be  sufficient. 

There  is  in  addition  one  factor  which  may  be  regarded  as  therapeutic 
or  at  least  prophylactic,  and  which  is  deserving  of  more  than  a  passing 
notice,  viz.  the  exercise  of  great  care  in  the  avoidance  of  injuries  to  the 
pericemental  membrane,  wherever  there  is  a  possibility  of  the  presence 
of  the  unfortunate  diathesis. 

However  ingenious  our  interpretation  of  pathological  conditions 
may  be,  and  however  plausible  our  deductions  may  appear,  the  ultimate 
test  of  their  value  will  be  the  readiness  with  which  they  yield  to  and 
disappear  under  appropriate  treatment. 

If  pyorrhea  alveolaris  be  a  manifestation  of  the  gouty  diathesis,  and 
the  symptoms  and  pathological  conditions  which  characterize  it  be  ex- 
cited and  maintained  by  the  deposit  and  pressure  of  uric  acid  and  its 
salts,  it  should  be  in  general  terms  amenable  to  the  therapeutic  measures 
which  have  been  efficacious  in  the  treatment  of  all  other  forms  of  gout 
in  other  portions  of  the  body.  It  must  be  borne  in  mind,  however,  that 
though  a  case  be  cured  for  a  period  of  six  months,  or  even  a  year,  this 
does  not  preclude  a  relapse  should  the  patient  return  to  an  improper 
diet  or  irregular  mode  of  life.  It  is  hardly  necessary  to  say  that  this 
is  true  of  all  diathetic  diseases.  In  individuals  predisposed  to  uric  acid 
aacumulations,  a  new  mode  of  life  is  to  be  instituted  and  followed  with 
extreme  care  for  a  long  period  of  time. 

The  conclusions  entertained  may  be  represented  in  a  condensed  form 
in  the  following  postulates  : 

(1)  Pyorrhea  alveolaris  of  constitutional  origin — which  is  its  most 
destructive  and  unyielding  form — primarily  begins  as  a  local  inflam- 
matory disorder  in  tissues  on  the  side  of  the  root  near  the  apical  ex- 
tremity, and  secondarily  advances  in  the  very  large  majority  of  cases 
toward  the  gingival  borders. 

(2)  The  cause  of  this  inflammation,  or  gingivitis  and  pericementitis, 
is  the   plasma  exudation   from   the  bloodvessels,  freighted  with  salts 


520  PYORRHEA   ALVEOLARIS. 

which  in  their  <l('|)<>sili()n  and  crystallization  n|>(tn  the  (•ciiicntuni  ol"  the 
root  and  inliltration  oi"  the  more  vascnlar  tissues,  exert  the  inHuenee 
ot"  foreiiiii  hodies  and  react  as  irritants. 

(.">)  The  salts  in  ((uestion,  as  disclosed  by  chemical  analysis,  are  cal- 
cium and  sodium  urates,  free  uric  acid,  and  calciiun  phosphate. 

(4)  The  chemical  nature  of  these  salts  indicates  a  condition  of"  the 
blood  in  which  tliere  is  an  excess  of  uratic  salts  and  uric  acid  due  to 
either  increased  fonnation  or  imperfect  cliiniinifion. 

(5)  The  excess  of  these  salts,  as  is  well  known,  is  reuarded  by  ^r^n- 
eral  patholoirists  as  indicative  of  a  faulty  metabolism,  and  is  the  imme- 
diate cause  of  a  series  of  local  disturbances  to  which  the  term  ti'outv  has 
been  ap|)lied,  the  nutritional  disturbance  giving  rise  to  what  is  known 
as  the  "  uric  acid  diathesis." 

(6)  x\n  attentive  study  and  accurate  observation  of  the  various 
organs  and  tissues  of  patients  suifering  M'ith  ])yorrhea  alveolaris  have 
disclosed  the  coexistence,  in  a  very  large  projxtrtion  of  them,  of  one  or 
more  local  expressions  of  this  constitutional  diathesis. 

(7)  Recognition  of  the  fact  that  a  constitutional  malady  presents 
itself,  one  phase  of  which  oidy  has  claimed  the  attention  of  the  dental 
]>ractitioner,  indicates  that  a  treatment  designed  to  be  curative  must 
have  reference  not  oidy  to  the  local  expression,  but  especially  to  this 
important  systemic  condition  as  well. 

(8)  Results  from  constitutional  treatment  in  connection  with  the 
usual  local  ai)plications  in  a  number  of  well-authenticated  cases  of 
j)yorrhea  alveolaris  have  been  so  markedly  satisfactory  that  the  writer 
feels  fully  justified  in  his  assumptions  regarding  the  origin  of  the 
disease. 

While  the  foregoing  pages  embody  views  quite  consistent  with  an 
extended  experience,  yet  the  writer  fully  a})})reciatcs  the  fact  that  many 
abnormal  conditions  closely  allied  in  superficial  characteristics  to  those 
above  recognized  and  described  may  exist  without  any  other  local 
expressions  indicating  a  uric  acid  dyscrasia. 

The  association  of  the  class  of  dental  diseases  included  under  the 
generic  title  of  pyorrhea  alveolaris  with  conditions  of  general  mal- 
nutrition has  been  recognized  by  many  writers  during  the  past  hun- 
dred years,  but  until  within  very  recent  times  no  systematic  attempt 
had  been  made  at  their  classification.  Dr.  M.  L.  Rhein,  who  has 
closely  studied  the  relations  existing  between  general  disorders  and  the 
dental  diseases,  finding  that  many  general  diseases  are  accom])anied  by 
the  symptom  pyorrhea  alveolaris,  and  that  the  dental  disorder  persists 
so  long  as  the  general  disease  is  in  activity,  suggests  that  the  diseases 
known  under  the  latter  title  be  divided  into  two  classes — pyorrhea 
simplex  and   pyorrhea  comjjfex. 


GOUTY  PERICEMENTITIS.  521 

Under  the  head  pijorvhea  simplex  are  included  all  of  those  varie- 
ties and  cases  in  which  local  therapeutic  measures  suffice  to  effect 
a  cure.^ 

Pyorrhea  complex  covers  those  cases  and  varieties  in  which  local 
therapeusis  fails  to  subdue  the  dental  disease,  and  which  are  associated 
with  some  perversion  of  general  nutrition.  This  class  is  subdivided 
into  four  groups  :  (a)  Those  due  to  nutritional  disorders  such  as  gout, 
diabetes,  chronic  rheumatism,  .  nephritis,  scurvy,  chlorosis,  anemia, 
leukemia,  pregnancy ;  (6)  Those  occurring  during  attacks  of  acute  infec- 
tive diseases,  as  typhoid  fever,  tuberculosis,  malaria,  acute  rheumatism, 
pleurisy,  pericarditis,  syphilis ;  (c)  Those  due  to  nervous  disorders, 
cerebral  diseases,  spinal  diseases,  neurasthenia,  hysteria  ;  {d)  Con- 
ditions resulting  from  the  action  of  toxic  drugs — mercury,  lead, 
iodids. 

Dr.  Ehein  believes  from  his  studies  that  each  member  of  the  group 
of  pyorrhea  complex  has  a  distinctive  clinical  expression,  which  might 
be  utilized  as  diagnostic  signs  of  the  constitutional  conditions. 

One  who  is  familiar  with  oral  abnormalities  and  able  to  differentiate 
them  must  be  very  liberal  in  the  interpretation  of  causes  in  order  to 
embrace  the  wide  range  of  pathological  conditions  which,  in  some  stages 
of  development,  present  appearances  that  would  or  could  very  properly 
be  termed  pyorrhea  alveolaris,  yet  whose  very  ready  response  to  topical 
remedies  would  naturally  suggest  that  they  were  not  associated  with  a 
uric  acid  habit.  While  fully  recognizing  the  fact  that  this  uric  acid 
dyscrasia  can  be  associated  with  almost  any  disease  which  is  a  concomi- 
tant of  malnutrition,  we  must  remember  and  fully  appreciate  the  fact 
that  imperfect  assimilation  of  food  and  faulty  metabolism  are  often 
responsible  for  local  abnormalities,  and  at  the  same  time  they  may  be 
factors  in  the  establishment  of  a  uric  acid  dyscrasia. 

In  one's  judgment  of  the  soundness  or  unsoundness  of  theories  or 
hypotheses,  the  fact  must  not  be  overlooked  that  affections  of  the  kid- 
neys, the  liver,  the  lungs,  the  heart,  the  mucous  membrane,  the  stomach, 
etc.  may  exist  without  any  other  recognized  expression,  or  we  may  have 
irritation  of  the  pericemental  membrane  alone  associated  with  any  one 
of  them,  the  disturbance  of  the  normality  of  this  tissue  being  severe  or 
slight  as  the  functional  or  organic  abnormality  of  the  organ  is  exalted 
or  inconspicuous. 

While  in  the  previous  pages  the  treatment  advocated  had  reference 
mainly  to  that  form  of  pyorrhea  the  concomitant  of  the  gouty  diathesis, 
it  must  nevertheless  be  borne  in  mind  that  a  similar  condition  of  the 
pericemental  membrane  is  at  times  associated  with  other  perversions  of 
the  general  nutrition,  as  pointed  out  by  Dr.  M.  L.  Rhein,  and  which 
1  Dental  Cosmos,  1894,  p.  780. 


522  PYORRHEA   ALVEOLA RIS. 

tlu-rcloiv  must  ircoivc  trcatincnt  ('specially  adapted  to  the  <;ciiei-al  con- 
stitutional state. 

Inasmucli  as  these  constitutional  conditions  are  complex  in  their 
manifestations  and  their  medicinal  and  hygienic  management  almost 
exclusively  in  the  hands  of  the  physician,  the  duty  of  the  dental  prac- 
titioner is  confined  largely  to  the  question  of  diagnosis  ;  the  local  treat- 
ment, however,  must  be  varied  in  accordance  with  the  peculiarities  of 
the  local  pathological  condition. 


CHAPTER    XX. 

DISCOLOEED  TEETH  AND  THEIR  TREATMENT. 

By  Edwaed  C.  Kiek,  D.  D.  S. 


DiscOLOEATioisr  of  a  tooth  is  consequent  upon  death  of  its  pulp. 
While  death  of  the  pulp  does  not  always  or  necessarily  involve  dis- 
coloration of  the  tooth  structures,  yet  when  the  condition  does  exist  the 
general  cause  is  as  stated.  Reference  is  here  made  to  a  progressive 
interstitial  staining  of  the  entire  dentin  structure,  and  is  exclusive 
of  certain  metallic  stains,  and  also  localized  stains  resulting  from  the 
imbibition  of  pigmentary  matters  which  occasionally  are  observed  where 
small  areas  of  dentin  have  become  denuded  of  enamel  covering,  or 
where  the  latter  has  been  so  imperfectly  formed  as  to  afford  an  in- 
sufficient barrier  to  the  ingress  of  pigmentary  matters  from  the  food 
or  oral  secretions. 

Three  classes  of  conditions  are  presented  for  consideration  and  treat- 
ment :  First,  cases  where  discoloration  has  resulted  from  death  of  the 
pulp  due  to  causes  other  than  its  exposure  ;  second,  discoloration  from 
pulp  death  consequent  upon  exposure ;  and  third,  special  discolorations 
due  to  adventitious  causes  superadded  to  the  conditions  affecting  the 
cases  included  in  the  foregoing  second  division. 

Any  of  the  numerous  traumatic  causes  which  bring  about  death  of 
the  pulp,  e.  g.  blows,  sudden  contact  with  hard  substances,  biting 
threads,  violent  thermal  shocks,  the  injudicious  application  of  continuous 
force  in  regulating,  or  the  application  of  arsenous  oxid  to  the  dentin 
(see  p.  425),  where  no  exposure  or  only  minute  exposure  of  the  pulp 
exists,  may  produce  hyperemia  and  congestion  of  the  pulp,  or  strangu- 
lation of  its  circulatory  system,  the  formation  of  emboli,  thrombus, 
hemorrhagic  infarct,  etc.,  leading  to  a  breaking  down  of  the  corpus- 
cular elements  of  the  blood,  the  escape  of  hemoglobin  from  the  stroma 
of  the  red  corpuscles,  its  solution  in  the  blood  plasma,  and  resulting 
infiltration  of  the  tubular  structure  of  the  dentin  by  the  hemoglobin 
solution,  giving  the  tooth  a  distinctly  pinkish  hue  when  examined  by 
direct  or  transillumination. 

Teeth  so  affected  rapidly  change  in  color  through  various  gradations 
in  tint  from  the  original  pinkish  hue,  which  becomes  yellow  ;  this,  grow- 
ing darker,  passes  into  brow^n,  and  after  the  lapse  of  considerable  time 
the  tooth  may  become  a  permanent  slaty  gray  or  black. 

523 


r)24  DJscnLouKi)  tkktii  asd  their  treatment. 

"^riic  violence  of  tlie  |Hil|(itis  priM-ediiij;-  tlie  death  and  di-inte(>ration 
ui'  tlie  jtidj),  in  a  t'onsidei"al>l<'  de^i-ee  determines  the  rajiidity  of"  the 
process  ot"  sul)se(|neiit  tooth  diseoloratioit.  \\  heri'  e(tnjj!:esti(»n  of  the 
pulj)  has  been  relatively  slight  and  the  necrotic  |)n)cess  has  proceeded 
slowly,  the  sudden  infiltration  of  the  di-ntin  with  henioglohin  does  not 
occur,  consequently  the  initial  change  in  color  following  con»j)lete  death 
of  the  pulp  may  be  so  slight  as  to  escape  detection  except  upon  most 
searching  examination  with  special  means  of  illumination,  and  even 
then  may  be  manifested  only  by  a  slight  diminution  in  the  normal 
transluccncy  of  the  tooth  as  compared  with  adjoining  teeth.  Such  teeth, 
iiowever,  if  permitted  to  remain  untreated,  eventually  grow  darker, 
and  while  they  may  not  acquire  a  degree  of  discoloration  equal  to  those 
which  have  sutiered  sudden  and  violent  death  of  the  pulp,  still  they 
become  so  unsightly  as  to  demand  treatment  for  the  restoration  of 
their  normal  color. 

The  Rationale  of  the  Process  of  Discoloration. — In  teeth  dis- 
colored as  a  consequence  of  the  death  of  the  pulp  without  its  exposure — 
viz.  those  of  the  first  class — it  is  evident  that  the  sources  of  pigmenta- 
tion are  internal  to  the  tooth  and  are  to  be  sought  for  solely  in  the 
products  of  decomposition  of  the  elements  of  the  pulp  ti-ssue  and  of  its 
vascular  suj)})ly. 

The  proteid  elements  of  the  pulp  tissue  are  complex  combinations 
of  carbon,  oxygen,  hydrogen,  nitrogen,  sulfur,  and  phos])horus,  which 
in  their  gradual  breaking  down  by  the  proce-s  of  putrefactive  decom- 
position are  split  up  finally  into  carbon  dioxid,  water,  ammonia,  and 
hydrogen  sulfid,  with  possibly  the  formation  of  traces  of  phosphatic 
salts.  The  group  of  substances  entering  into  the  comjxisition  of  the 
histological  elements  of  pulp  tissue  contains  no  constituents  which  in 
the  progressive  changes  resulting  from  putrefactive  decomposition 
should  form  compounds  likely  to  cause  permanent  discoloration  of 
the  tooth  structures. 

When,  however,  the  vascular  supply  is  considered  as  a  factor,  the 
explanation  of  the  cause  of  discoloration  in  the  cases  in  (piestion 
])ecomes  reasonably  clear.  The  red  blood  corpuscles  contain  as  their 
characteristic  component  hemoglobin  or  oxyhemoglobin  according  as  the 
blood  is  venous  or  arterial,  and  this  substance  is  its  essential  coloring 
ingredient.  When  undergoing  gradual  decomposition,  hemoglobin 
passes  through  a  variety  of  alterations  in  its  chemical  constitution, 
accompanied  by  a  corresponding  series  of  color  changes. 

A  familiar  illustration  of  these  color  changes  is  furnished  by  the 
cycle  of  color  alterations  witnessed  in  a  bruise.  Immediately  following 
an  injury  to  the  flesh,  of  the  character  alluded  to,  an  extravasation  of 
blood  in  the  bruised  territory  occurs,  causing  undue  reddening  of  the 


RATIONALE  OF  THE  PROCESS  OF  DISCOLORATION. 


ry2?> 


skin  ;  this  is  soon  followed  by  an  increasing  darkening  of  the  tissue, 
until  there  results  what  is  popularly  termed  a  "  black-and-blue  spot." 
Further  decomposition  of  the  coloring  matter  of  the  extravasated  blood 
induces  a  variety  of  color  changes  ranging  through  the  scale  of  yellows 
and  browns,  until  the  pigmentary  matter  is  finally  removed  by  absorp- 
tion through  the  capillary  bloodvessel   system  of  the  part. 

In  passing  through  its  cycle  of  color  changes,  hemoglobin  undergoes 
several  alterations  in  composition  during  which  a  number  of  definite 
compounds  are  formed,  each  having  marked  chromogenic  features.  Of 
these  decomposition  products,  methemoglobin  (brownish  red),  hemin 
(bluish  black),  hematin  (dark  brown  or  bluish  black),  and  hematoidin 
(orange),  are  the  most  important  and  best  known.  While  the  gradual 
decomposition  of  the  coloring  matter  of  the  blood  here  noted  may  and 
doubtless  does  account  for  certain  phases  of  tooth  discoloration,  other 
factors  which  exert  a  profoundly  modifying  influence  upon  the  process 
are  yet  to  be  considered. 

The  putrefactive  decomposition  of  the  proteid  elements  of  the  pulp 
results,  as  before  stated,  in  the  production  of  hydrogen  sulfid  in  con- 
siderable quantity.  The  albumins  contain  from  0.8  to  2.2  per  cent,  of 
sulfur  (Hammarsten)  which  in  the  splitting  up  of  the  compound  during 
putrefaction  yields  a  large  amount  of  hydrogen  sulfid.  In  pulp  decom- 
position this  hydrogen  sulfid  is  generated  in  contact  with  the  hemoglobin 
and  necessarily  exerts  a  marked  modifying  action  upon  the  decomposi- 
tion process  of  that  substance.  Miller  says,  "  If  a  current  of  sulfuretted 
hydrogen  is  conducted  through  fresh  blood  or  a  solution  of  oxyhemo- 
globin in  the  presence  of  air  or  oxygen,  sulfomethemoglobin  is  formed, 
which  is  greenish  red  in  concentrated  solutions  and  green  in  dilute  solu- 
tions. If  we  lay  a  freshly  extracted  tooth  in  a  mixture  of  meat  and 
saliva  so  that  a  part  of  the  enamel  surface  remains  free,  and  moisten 
the  surface  with  blood,  it  will  take  on  a  dirty-green  color  if  kept  at 
blood  temperature  in  an  absolutely  moist  condition  for  from  twenty-four 
to  forty-eight  hours.  It  is  quite  possible  that  the  dirty-green  deposits 
which  form  in  putrid  conditions  of  the  mouth,  in  stomatitis  mercurialis, 
scorbutica,  gangrenosa,  etc.,  or  even  in  inflammatory  conditions  of  less 
importance,  as  well  as  in  cases  of  absolute  neglect  of  the  care  of  the 
mouth,  may  owe  their  green  color  to  the  presence  of  sulfomethemo- 
globin." 

As  in  pulp  decomposition  hydrogen  sulfid  is  being  formed  in  the 
presence  of  hemoglobin,  this  fact  warrants  the  belief  that  a  combina- 
tion takes  place  resulting  in  the  formation  of  this  same  compound, 
which  Miller  regards  as  productive  of  certain  stains  upon  the  external 
surface  of  the  teeth. 

The  slaty  gray  or  bluish  pigmentation  always  noticeable  upon  the 


r)26  DISCOLORED   TEETH  ASD   THEIR   TREATMENT. 

visceral  walls  and  tVcc^iU'iitly  hciieath  the  skin  of  animal  bodies  under- 
going putrefactive  degeneration  i<  a  familiar  ixaniple  of  the  aetion  of 
hvdrogen  sulfid  upon  deeomposin*^  liemot::lol)in  in  liemorrha*^ie  extrava- 
sations, and  is  a  process  and  form  of  pigmentation  exactly  analogous  to 
that  which  is  here  described  as  taking  place  in  the  dentinal  structure 
from  putrefactive  decomposition  of  the  pulp,  "  When  red  corpuscles 
are  just  beginning  to  disintegrate,  the  coloring  matter  formed  is  hemo- 
globin ;  but.  the  yellow  and  brown  granular  masses  found  in  cells  and 
lying  free  in  tissues  are,  as  a  rule,  derivatives  of  hemoglobin,  not  hemo- 
globin itself.  These  derivatives  are  divided  into  two  groups  according 
as  thev  contain  iron  or  not,  the  former  being  called  hemosiderin,  the 
latter  hematoidin."  '  "  When  acted  upon  by  ammonium  sulfid  (a  deriv- 
ative of  ])utrefactive  decomposition  of  albumin)  hemosiderin  becomes 
black,  iron  sulfid  being  formed."^  (jrohe*  believes  that  as  a  result  of 
putrefaction  iron  is  liberated  from  its  compound  with  hemoglobin,  so 
that  when  thus  freed  it  readily  c  >mbines  with  the  hydrogen  sulfid. 

Iron  is  the  most  important  element  to  be  considered  in  the  list  of 
factors  causing  the  discoloration  of  this  group  of  cases.  It  is  the  iron 
constituent  of  the  red  corpuscles  which  is  the  essential  chromogenic 
fiictor  from  first  to  last  in  their  cycle  of  color  changes. 

The  process  of  putrefactive  decomposition  consists  of  a  series  of 
chemical  changes  wrought  out  through  the  agency  of  micro-organisms, 
involving  the  breaking  down  by  successive  stages  of  highly  complex 
organic  compounds  and  their  resolution  into  compounds  of  much  sim- 
pler constitution.  It  is  not  known  to  what  extent  this  splitting  up  of 
the  components  of  the  pulp  and  its  vascular  elements  is  ultimately  car- 
ried in  the  series  of  changes  resulting  in  the  permanent  discoloration 
of  the  tooth.  From  what  is  known  of  the  ultimate  composition  of  the 
compounds  involved  it  may,  however,  be  safely  inferred  that,  reduced 
to  its  lowest  terms,  the  result  would  be  the  formation  of  iron  sulfid,  the 
elements  of  w'hich,  with  the  exception  of  some  unimportant  alkaline  and 
earth v  salts,  are  the  only  ones  entering  into  the  original  compounds 
which  are  fixed  and  therefore  capable  of  forming  a  stable  residuum  in  the 
tubular  structure  of  the  dentin.  While  iron  sulfid  as  such  cannot  be 
held  wholly  accountable  for  the  final  bluish-black  color  of  a  tooth  which 
has  reached  the  stage  of  permanent  discoloration,  the  pigmentation  is 
almost  certainly  due  either  to  it  or  to  some  allied  comj)ound  in  which 
iron  atid  sulfur,  with  some  organic  constituents,  largely  enter,  and  which 
bv  a  further  slight  decom])Osition  would  yield  true  iron  sulfid. 

The  significance  and  importance  of  a  recognition  of  the  possible 
presence  of  the  iron  compound  as  a  factor  in  tooth  discoloration  is 
further  brought  out  in  the  study  of  bleaching  methods  (pp.  542  and  558). 

'  Ziegler,  General  Fathology,  1895.  ''  Ibid.  ^  Virchoii/s  Archiv.,  Bd.  xx. 


DISCOLORATION  FOLLOWING  DEATH  OF  THE  PULP.        527 

Discoloration  of  Teeth  foUo-wing  Death  of  the  Pulp  consequent 
upon  its  Exposure. — When  death  and  decomposition  of  the  pulp  is 
consequent  upon  exposure  of  that  organ,  through  caries  or  otherwise,  to 
the  irritative  influences  of  infective  agents  present  in  the  oral  secretions 
and  food,  or  to  thermal  shock,  etc.,  the  putrefactive  process  involving 
the  pulp  tissues  is  modified  in  character  and  rapidity  to  a  degree  which 
may  affect  the  character  of  the  resulting  discoloration.  Thus  the  yel- 
lowish or  brownish  discoloration  so  often  seen  in  teeth  whose  pulps 
have  been  devitalized  through  systemic  or  traumatic  causes,  and  which 
in  many  cases  appears  to  be  more  or  less  permanent  in  character,  is 
rarely  observed  in  those  teeth  whose  pulps  have  been  devitalized  through 
exposure  by  caries. 

In  these  latter  cases  the  progress  of  the  putrefactive  process  is  com- 
paratively rapid,  the  conditions  being  more  favorable  so  that  the  color- 
ing matter  of  the  blood  is  sooner  reduced  to  its  lowest  terms  in  the  scale 
of  decomposition  products,  i.  e.  to  the  slaty  blue  or  black  pigmentation 
before  noted.  In  addition  to  the  increased  rapidity  of  putrefactive  de- 
composition incident  to  cases  of  discoloration  following  pulp  exposure, 
another  and  important  modifying  factor  in  the  process  of  discoloration 
is  the  ingress  afforded  to  the  oral  fluids,  food  materials,  and  other  ad- 
ventitious substances  which  find  their  way  into  the  mouth  and  ulti- 
mately, through  the  open  cavity  of  the  tooth,  to  its  pulp  canal  •  and 
thence  to  the  tubular  structure  of  the  dentin.  These  extraneous  sub- 
stances, in  the  course  of  time,  may  infiltrate  the  tooth  structure,  and 
while  no  especially  noticeable  or  characteristic  effect  may  be  observed 
so  far  as  color  is  concerned,  yet  they  frequently  exert  an  influence  upon 
the  coloration  of  the  tooth  which  so  alters  its  character  as  to  render 
successful  bleaching  treatment  extremely  difficult  and  a  resort  to  special 
methods  or  a  variety  of  methods  necessary. 

The  introduction  of  fatty  or  oily  substances  or  of  astringent  and 
coagulant  matters,  for  example,  may  act  upon  the  coloring  matter  in 
such  a  Avay  as  to  permanently  "  set "  it  in  the  same  manner  that  mor- 
dants form  insoluble  compounds  or  lakes  with  the  dye-stuffs  used  in 
the  dyeing  of  textile  fabrics. 

Another  and  important  class  of  substances  which  frequently  are  the 
cause  of  staining  of  the  tooth  structure  are  metallic  salts  which  are  used 
in  dental  therapeutic  treatment  or  are  accidentally  formed  during  the 
application  of  corrosive  medicaments  to  the  teeth,  through  the  action  of 
such  remedies  upon  fillings  in  situ  or  upon  the  instruments  by  which 
the  applications  are  made.  For  example,  the  use  of  iodin  or  sulfuric 
acid  in  connection  with  steel  instruments  and  the  subsequent  use  of 
medicaments  containing  tannin  as  an  ingredient. 

The  treatment  of  these  conditions  will  be  separately  considered. 


528  DISCOLORED   TEETH  AND   THEIR   TREATMENT. 

Tooth-Bleaching. — Use  of  Chlorin. 

Nature  of  the  Problem  Involved  in  Tooth-Bleaching. — The 
lilciuliiiiii- |)r()C('ss  is  (IcjJCiKlcnt  upon  a  clicmical  reaction  hctwcni  a  coni- 
pdiiiid  lia\  iiiu  color  and  sonic  substance  capable  of  .'^o  affecting  its  com- 
position that  the  color  is  dischargeil,  or,  in  other  words,  of  so  aflccting 
the  integrity  of  the  color  niolecnle  as  to  destroy  its  identity,  which 
resnlts   in  a   loss  of  its  distinguishing  characteristic,   viz.  its  color. 

The  snbstances  concerned  in  discoloration  of  tooth  structure,  as  has 
been  previously  shown,  are  derived  from  the  pulp  and  its  vascular 
elements  and  the  organic  contents  of  the  tubular  structure  of  the  dentin, 
through  the  gradual  jiutrefactive  processes  which  become  operative 
subscipient  to  the  death  of  the  pidp.  These  pigmentary  })roducts  of 
pulp  ilccomposition  wc  know  to  be  organic  in  character ;  and  further, 
that  they  exhibit  the  pro])erty  of  color  by  virtue  of  definite  conditions 
of  molecular  com])osition — that  is  to  say,  a  certain  arrangement  of  a 
definite  kind  and  number  of  atoms  has  resulted  in  the  formation  of  a 
molecule  having  its  individual  group  of  cliemical  and  physical  prop- 
erties, among  Mhich  latter  is  a  characteristic  co/or. 

AA'hatever  brings  about  an  alteration  in  the  composition  of  the  mole- 
cule at  once  destroys  the  identity  of  the  matter  so  treated.  Hence  if 
we  can  act  upon  the  coloring  matter  winch  gives  rise  to  the  staining  of 
a  tooth  by  means  of  an  agent  capable  of  effecting  an  alteration  in  the 
atomic  arrangement  or  composition  of  the  color  molecule,  we  may  expect 
to  remove  or  discharge  its  color  feature. 

Two  general  classes  of  substances  have  been  successfully  used  as 
bleaching  agents  :  First,  those  which  act  by  virtue  of  their  jjower  to 
evolve  oxygen  in  the  active  or  nascent  condition,  and  known  a>  oxidiz- 
ing agents  ;  second,  tiiose  which  act  in  an  opjxtsite  manner  i)y  virtue 
of  their  strong  affinity  for  oxygen  and  which  are  called  reducing  agents. 
The  oxidizing  bleachers  destroy  the  identity  of  the  color  molecule  by 
seizing  upon  its  hydrogen  element  to  form  water.  The  reducing  agents 
act  by  removing  the  oxygen  atom  from  the  color  molecule  to  form  by- 
products depending  ui)()n  the  character  of  the  reducing  agent  used. 

Chlorin  and  its  associates  iodin  and  bromin  act  as  indirect  o.vidizinr/ 
hfeachers ;  the  dioxid  of  hydrogen  and  of  sodium  are  direct  oxidizers. 
Potassium  ])ermanganate  may  also  be  classed  with  this  group,  though  its 
successful  use  as  a  bleaching  agent  depends  upon  a  subsequent  treat- 
ment of  the  substance  to  be  bleached  with  some  solvent  capable  of  re- 
moving the  manganese  dioxid  formed  as  a  by-])roduct  of  the  action  of 
the  permanganate.  It  has  somewhat  extensive  and  satisfactory  use  as 
an  agent  for  bleaching  s])onges,  and  has  been  used  for  bleaching  teeth, 
but  is  of  greatly  inferior  value  to  other  agents  for  the  latter  use. 


TOOTH-BLEACHING— USE   OF  CHLOBIN.  529 

The  only  agent  belonging  to  the  group  of  reducing  bleachers  which 
has  thus  far  been  found  available  for  bleaching  teeth  is  sulfurous  oxid, 
either  in  the  gaseous  condition  or  in  aqueous  solution. 

Chlorin  as  a  Bleacher. — The  general  use  of  chlorin  as  a  bleaching 
agent  in  the  arts  no  doubt  suggested  its  use  in  the  treatment  of  tooth 
discoloration.  Its  introduction  as  a  tooth-bleaching  agent,  as  well  as  the 
assembling  of  the  general  principles  of  tooth  bleaching  into  a  co-ordi- 
nate system,  are  due  to  Dr.  James  Truman,  whose  method  depends  upon 
the  liberation  of  chlorin  from  calcium  hypochlorite,  commonly  called 
bleaching  powder  or  "  chlorinated  lime,"  in  the  pulp  chamber  and  cav- 
ity of  decay  in  the  tooth.  Chlorin  is  liberated  from  the  bleaching  pow- 
der by  the  action  of  dilute  acetic  acid ;  this  taking  place  in  contact  with 
the  discolored  structure,  it  is  rapidly  bleached  as  a  result  of  the  action 
of  the  chlorin  upon  the  coloring  matter  contained  in  the  dentinal  tubules. 
Numerous  modifications  of  this  original  method  of  bleaching  tooth  struc- 
ture have  been  suggested,  but,  as  the  ultimate  result  in  each  is  accom- 
plished through  the  activity  of  chlorin,  a  rational  understanding  of  the 
mode  of  action  of  chlorin  in  this  relation  is  of  importance  as  an  aid 
to  the  intelligent  use  of  those  methods  for  tooth-bleaching  which  are 
dependent  upon  or  owe  their  efficacy  to  that  agent. 

Chlorin  is  an  elementary  gaseous  body,  greenish  in  color,  soluble  in 
water,  having  a  disagreeable  odor,  intensely  irritating  to  the  air-passages 
when  inhaled,  and  poisonous  when  breathed  in  sufficient  quantity.  It 
has  a  strong  affinity  for  all  metallic  bodies,  entering  into  direct  combi- 
nation with  a  number  of  them,  under  favorable  circumstances,  with 
great  energy — forming,  as  a  rule,  compounds  that  are  soluble  in  water. 

One  of  its  distinguishing  features  and  one  which  is  directly  concerned 
in  its  use  as  a  bleaching  agent  is  its  strong  affinity  for  hydrogen.  So 
strong  is  this  affinity,  that  when  a  molecule  of  chlorin  is  brought  into 
contact  with  a  molecule  of  water  under  favorable  conditions,  the  hydro- 
gen of  the  water  molecule  is  seized  upon  by  the  chlorin  to  form  chlor- 
hydric  acid  and  the  oxygen  is  set  free  in  the  nascent  state,  a  condition 
under  which  its  oxidizing  powers  are  exhibited  in  their  greatest  intensity. 
This  powerful  affinity  of  chlorin  for  hydrogen  enables  it  to  decompose 
many  other  hydrogen-containing  molecules  in  a  similar  manner,  form- 
ing chlorhydric  acid  and  destroying  the  identity  of  the  matter  acted 
upon. 

It  has  been  shown  that  all  organic  compounds  which  are  the  products 
of  the  vital  processes  of  the  animal  body  contain  hydrogen  as  an  im- 
portant constituent.  This  applies  also  to  the  decomposition  products 
whose  presence  in  the  tubular  structure  of  the  dentin  is  the  cause  of 
tooth  discoloration. 

These  organic  stains  exhibit  the  property  of  color  by  virtue  of 
34 


530  DISCO loj:i:i)  tekth  axd  their  TREATMEyr. 

certain  ileHnite  ooiiditions  of  molecular  composition  ;  hence,  if  chlorin 
is  caused  to  act  upon  the  coloring  matter  which  causes  the  staining  of 
a  tooth,  by  seizing  upon  and  coml)ining  with  the  hydrogen  of  the 
organic  pigment,  the  identity  of  the  compound  as  such  is  destroyed, 
and  its  characteristic  feature,  tliat  of  color,   is  lost. 

The  principle  here  outlined  is  involved  in  w  hat  is  termed  the  direct 
action  of  chlorin  in  bleaching.  There  is,  however,  anotlur  method  by 
which  chlorin  is  believed  to  act  as  a  bleacher  in  which  its  function  is 
indirect.  In  some  cases  it  has  been  observed  that  chlorin  fails  to  act 
except  in  the  presence  of  moisture,  and  the  rationale  of  this  is  that  the 
bleachini;  under  such  conditions  is  effected  bv  nascent  oxv<ren  liberated 
from  the  water  molecule  when  tlic  chlorin  combines  with  its  hydrogen 
to  form  chlorhydric  acid  ;  thus  :  CL  —  H.^O  ^=  2HC1  f  O.  That  such 
is  the  nature  of  the  process  in  many  cases  is  a  reasonable  deduction 
fr()m  the  behavior  of  chlorin  under  analogous  conditions  where  it  acts 
indirectly  as  an  oxidizing  agent. 

Whatever  may  be  the  exac;t  nature  of  its  ultimate  action,  it  is  to  be 
borne  in  mind  that  its  bleaching  effect  is  due  solely  to  the  alteration 
which  it  makes  in  the  composition  of  the  color  molecule,  and  that  it 
has  no  solvent  power  whatever  on  the  organic  matter  u])on  which  it 
acts.  It  changes  its  characteristics,  but  does  not  remove  it  by  solution. 
It  should  be  also  noted  in  tliis  connection  that  the  chlorin  compounds 
of  most  of  the  metallic  elements,  especially  when  in  dilute  solution,  are 
almost  colorless  as  compared  with  many  of  the  other  metallic  com- 
pounds— the  oxids  and  sulfids  for  example.  Hence  it  is  that  where 
stains  owe  their  color  to  the  presence  of  certain  organic  compounds 
with  some  of  the  metals,  or  even  where  the  coloration  is  due  to  decom- 
position products  of  hemoglobin,  the  color  may  readily  be  discharged 
by  chlorin,  but  if  the  iron  chlorid  thus  produced  remains  in  the  tooth 
structure  it  is  gradually  decomposed  and  new  combinations  of  it  are 
liable  to  occur,  which  results  in  a  return  of  the  discoloration. 

All  tooth-bleaching  methods  should  aim  not  only  to  discharge  the 
color  by  suitable  chemical  means,  but  should  go  farther  than  this  and, 
as  far  as  it  may  be  possible  to  do  so,  remove  all  organic  debris  from  the 
tubules,  for  as  long  as  any  remains  the  tendency  to  a  return  of  the  dis- 
coloration is  always  a  possible  and  indeed  probable  menace  to  the  com- 
plete and  permanent  success  of  the  operation. 

Where  the  tubular  contents  cannot  be  successfully  removed,  the 
tendency  to  a  return  of  discoloration  may  be  combated  by  hermetically 
sealing  the  tubular  orifices  with  an  impermeable  resinous  varnish  or 
permanently  coagulating  them.  This  feature  is  described  more  fully  in 
relation  to  the  details  of  the  bleaching  procedure. 

Teeth  Suitable  for  the  Bleaching  Operation. — In  deciding  upon 


TOOTH-BLEACHING— USE  OF  CHLOBIN.  531 

the  advisability  of  attempting  the  bleaching  operation  in  any  given  case, 
the  general  conditions  which  determine  the  judgment  of  the  operator 
with  respect  to  all  dental  operations  should  govern  his  course. 

As  all  therapeutic  and  restorative  measures  in  dentistry  are  a  series 
of  compromises  with  disease  conditions  or  their  sequelae,  it  is  the  duty 
of  the  operator  under  all  circumstances  to  capitulate  upon  the  basis  of 
greatest  advantage  to  the  patient.  Therefore  if  discoloration  of  a  tooth  is 
practically  the  only  factor  in  the  problem  presented  by  a  given  case, 
the  eifort  should  be  made  to  restore  the  organ  to  its  normal  condition 
of  color.  The  same  rule  should  be  applied  to  all  cases  of  discolored 
teeth  in  which  structural  loss  by  caries  or  fracture  has  not  been  so  great 
as  to  preclude  a  satisfactory  restoration  by  proper  filling  or  replace- 
ment of  the  lost  structure  by  a  porcelain  inlay.  The  cases  in  which  it 
is  not  advisable  to  attempt  a  bleaching  operation  are  only  those  in  which 
loss  of  structure  is  so  extensive  as  to  require  a  crowning  operation. 

In  the  judgment  of  many  operators  it  is  considered  useless  to  at- 
tempt the  bleaching  of  any  teeth  excepting  the  incisors,  because  of  the 
difficulty  and  length  of  time  frequently  required  for  the  successful 
bleaching  of  canines,  bicuspids,  and  molars,  owing  to  the  thickness  of 
their  walls  and  the  consequent  depth  of  structure  requiring  treatment. 
It  is  also  held  to  be  useless  to  attempt  the  bleaching  of  teeth  which 
have  been  discolored  by  metallic  stains  throughout  their  structure. 
The  flillacy  of  such  a  view  is  self-evident  when  it  is  considered  that  if 
any  portion  of  the  dentinal  structure  of  a  discolored  tooth  is  amenable 
to  the  bleaching  treatment,  its  complete  restoration  is  simply  a  question  of 
continuance  or  repetition  of  the  operation  until  the  desired  end  is  attained. 

With  regard  to  discoloration  by  metallic  stains,  while  teeth  so  af- 
fected present  problems  of  great  complexity,  and  require  not  only 
special  study  but  the  application  of  special  methods  of  treatment  based 
npon  proper  recognition  of  the  chemical  relationships  involved  between 
the  nature  of  the  stain  and  that  of  the  agent  used  for  its  removal,  the 
attempt  should  be  made  in  justice  to  the  patient,  even  though  idtimate 
failure  result,  in  order  that  the  necessity  for  destruction  of  the  natural 
crown  for  the  purpose  of  its  replacement  by  an  artificial  substitute  may, 
if  possible,  be  postponed  for  as  long  a  period  as  may  be  attainable. 

Preparation  of  the  Tooth  for  the  Operation  of  Bleaching-. — Cer- 
tain general  details  are  necessary  to  be  observed  in  the  preparation  of 
teeth  for  the  bleaching  operation,  whatever  may  be  the  method  of  treat- 
ment employed. 

Appropriate  treatment  for  the  removal  of  all  septic  matter  from  the 
pulp  chamber  and  canal,  and  for  the  relief  of  any  existing  condition  of 
irritation  of  the  pericemental  membrane  and  tissues  of  the  apical  region, 
should  have  been  carried  out  and  the  tooth  brought  to  the  condition  in 


ry.V2  DlsvoLoltEl)   TEETH  AND   THEIR   TREATMENT. 

■\vliicli  ]MM*rnanont  closure  of  the  ;i])icnl  f'ornincn  of  the  root  ni;iy  he  safely 
pcrloriiK'd. 

'riic  nil»l)cr  (lam  sliould  he  adjusted  with  es]>eeial  care  and  oidv 
include  the  tooth  to  he  hleached.  Jf  two  adjoining;  teeth  are  to  be 
bleached  they  may  both  be  isolated  by  the  dam,  but  in  no  case  shoidd 
one  or  more  adjacent  normal  teeth  be  included  with  the  tooth  to  ))e 
bleached.  AVhile  the  inclusion  of  teeth  adjacent  to  the  one  which  is  the 
subject  of  any  ordinary  dental  operation  is  in  nearly  all  cases  desirable, 
tliere  are  g;ood  reasons  Avhy  such  a  j)lan  should  not  be  pursued  in  the 
bleaching  })roce(lure.  The  chemicals  used  for  the  pnrpo,se  may  ])()ssibly 
have  some  disintegrating  or  solvent  action  upon  the  enamel  structure, 
and  such  action,  should  it  occur,  should  be  confined  strictly  to  tiie  tooth 
undergoing  treatment  and  held  within  the  limits  of  safety  by  close 
observation  and  approju'iate  treatment,  Avhich  conditions  cannot  be  as 
thoroughly  controlled  and  the  })rocess  as  satisfactorily  managed  when 
several  teeth  are  included  within  the  territory  of  opei-ation. 

Furthermore,  as  nearly  all  of  the  bleaching  agents  used  or  those 
which  are  employed  as  adjuvants  in  the  process  have  a  more  or  less 
irritative  or  escharotic  effect  u])on  the  soft  tissues  of  the  mouth,  extra 
precautions  must  be  taken,  in  adjusting  the  dam,  against  leakage  at  its 
attachment  to  the  cervix  of  the  tooth.  As  the  chances  of  leakage  are 
greatly  multiplied  when  several  holes  are  punched  in  the  dam  for  ad- 
justment to  as  many  teeth,  it  is  for  this  reason  also  that  no  other  than 
the  tooth  to  be  treated  should  have  the  dam  adjusted  to  it. 

Supposing  the  tooth  to  be  an  upper  incisor,  the  dam  should  be 
slipped  over  it  and  the  margin  of  rubber  encircling  the  cervix  should 
be  gentlv  carried  under  the  free  margin  of  the  gum  either  by  means  of  a 
small  flat  burnisher  of  suitable  angle  and  curvature,  or  by  means  of  a 
waxed  floss-silk  thread.  One  or  two  turns  of  a  ligature  should  then  be 
thrown  around  the  cervix  below  the  dam  to  hold  it  securely  in  ])lace. 
The  dam  may  be  fixed  with  greater  security,  es])ecially  as  against  any 
accidental  traction  made  upon  it  during  the  operation,  by  fastening  it 
with  a  ligature  made  as  follows  and  thrown  around  its  cervix  : 

A  piece  of  waxed  ligature  silk  about  eighteen  inches  in  length  has 
a  large  knot  tied  at  about  its  middle  portion  by  making  six  or  eight 
turns  of  the  thread  loosely  around  the  end  of  the  index  finger  of  the 
left  hand.  Upon  withdrawing  the  finger  a  series  of  loops  are  had 
througli  w'hich  one  of  the  free  ends  of  the  thread  is  now  passed,  as 
in  making  the  first  half  of  a  flat  knot,  as  illustrated  in  Fig.  468. 
By  drawing  u])on  the  free  ends  of  the  thread  until  all  of  the  loops 
are  closed  upon  themselves,  a  hard  knot  of  more  or  less  spheroidal 
shape  is  formed  about  midway  between  the  ends  of  the  ligature.  The 
ligature  so  prepared  is  placed  around  the  tooth  in  such  a  manner  that 


TOOTH-BLEACHING— USE  OF  CHLOBIN.  533 

the  knot  as  described  shall  be  located  upon  and  at  the  middle  portion 
of  the  palatal  cervical  margin.  A  half  knot  is  then  made  by  tying  the 
ligature  in  front  so  that  it  shall  rest  directly  opposite  the  palatal  knot, 
viz.  at  the  middle  portion  of  the  labial  cervical  margin.  The  ligature 
is  drawn  into  fairly  close  contact  with  the  tooth,  and,  with  both  ends 
held  firmly  in  the  left  hand  and  drawn  somewhat  tense,  the  portion 
encircling  the  tooth  is  firmly  but  gently  forced  up  against  the  rubber 

Fig.  468. 


dam  and  gingival  margin,  the  ligature  at  the  same  time  being  drawn 
tightly  until  the  anatomical  constriction  of  the  tooth  at  its  cervix  will 
serve  to  hold  it  from  slipping  downward,  especially  upon  the  palatal 
aspect  of  the  tooth. 

When  the  ligature  is  found  to  be  securely  placed  as  described,  the 
knot  upon  the  labial  aspect  is  completed  and  further  enlarged  in  bulk 
by  re-tying  the  thread  four  or  five  times.  The  free  ends  of  the  ligature 
should  then  be  cut  off  close  to  the  knot.  As  an  additional  safeguard 
against  leakage  of  irritating  bleaching  agents  through  the  cervical 
attachment  of  the  dam,  and  out  upon  the  soft  tissues,  it  is  well  after 
making  the  tooth  perfectly  dry  to  paint  the  ligature  and  a  narrow  band 
of  its  adjacent  territory  with  chloro-percha,  which  will  effectually  prevent 
any  accident  from  leakage. 

The  placing  of  a  large  knot  upon  the  palatal  aspect  at  the  cervical 
margin  has  another  decided  advantage  in  that  it  not  only  holds  the  dam 
more  securely  against  slipping  downward,  but  holds  it  away  from  the 
palatal  surface,  which  is  ordinarily  the  point  of  entrance  to  the  pulp 
chamber  and  canals  in  these  cases.  The  point  of  canal  entrance  may, 
however,  be  through  an  approximal  cavity,  if  such  an  one  affords 
sufficient  access. 

The  canal  filling  in  all  cases  of  bleaching  without  exception  should 
be  gutta-percha.  No  other  material  used  for  canal  filling  possesses  the 
generally  desirable  qualities  needed  for  that  purpose  in  this  class  of 
cases.  The  extent  of  the  canal  filling  should  include  one-third,  or  at 
least  not  over  one-half,  of  the  distance  from  the  apex.  A  considerable 
portion  of  the  canal  beyond  the  level  of  the  gingival  margin  is  thus 
left  unfilled  in  order  that  the  coronal  end  of  the  root  may  be  bleached 
as  well  as  the  tooth  crown.  This  is  especially  necessary  where  more 
or  less  recession  of  the  gum  from  its  normal  attachment  has  occurred, 


53-4  DISCOLORED   TEETH  AND   THEIR   TREATMENT. 

loavintr  the  (HTvical  ociucntuni  ('Xj)()s('(l  to  tlio  action  of  tlu'  oral  fluids, 
looil,  etc.,  wliicli  have  a  tciKU'iicy  to  cause  discoloration  of  the  exposed 
root  tissue. 

The  root  heinj^  filled  as  directed,  all  fillinii^s  wherever  existent  in  the 
tooth  shouUl  be  removed.  This  is  a  preliniinarv  j)rocedure  which 
should  not  be  omitted  in  any  case,  but  where  any  bleaching  method  is 
used  which  involves  the  employment  of  chlorin  as  the  active  agent  it 
becomes  imperatively  necessary  for  reasons  which  are  ex])lained  in  con- 
nection with  the  description  of  the  chlorin  methods  (page  529).  Aside 
from  other  considerations,  the  removal  of  all  fillings  preparatory  to  the 
bleachiHg  operation  has  a  decided  value  in  facilitating  the  j)rocess  by  ex- 
posing an  increased  area  of  the  dentinal  structure  and  thereby  permit- 
ting the  action  of  the  bleaching  agent  over  a  larger  territory  of  ingress. 

AVhen  all  fillings  or  softened  tooth  structure  have  been  removed,  as 
well  as  all  septic  and  extraneous  matter  of  whatever  character,  by 
mechanical  process,  the  tooth  should  be  washed  thoroughly  with  dilute 
ammonia  water,  or  better  with  a  hot  solution  of  borax  in  distilled  water 
in  the  proportion  of  3j  to  f.5J.  The  object  of  this  treatment  is  to  re- 
move by  saponification  and  solution  all  fatty  matters  which  may  obstruct 
the  ingress  of  the  bleaching  agent  into  the  dentinal  structure. 

In  nearly  all  cases  where  discoloration  has  occurred  from  a  decom- 
posed pulj)  and  where  the  canals  and  pulp  chamber  have  been  left 
untreated,  there  will  be  observed,  on  opening  into  such  a  pulp 
chamber  for  the  first  time,  a  dark  layer  of  oily  or  greasy  material 
lining  itg  walls.  The  thorough  removal  of  this  dark  layer  should 
be  effected  prior  to  any  attempt  at  bleaching,  as  it  appears  to  prevent 
the  ingress  of  the  bleaching  agent  into  the  dentinal  structure.  The 
most  satisfactory  method  lor  removing  the  dark  greasy  layer  is  by  the 
use  of  suitable  instruments — either  properly  shaped  spoon  or  hoe  ex- 
cavators or  round  burs  in  the  engine.  The  thorough  removal  of  this 
layer  necessitates  free  access  to  the  pulp  chamber,  which  should  be 
as  a  general  rule  obtained  by  means  of  an  amj)le  opening  upon  the 
lingual  aspect  of  the  tooth  in  the  case  of  incisors,  and  through  the 
morsal  surface  in  bicuspids,  etc. 

Having  l\v  mechanical  means  and  through  tfie  agency  of  Ijorax  or 
ammonia  and  hot  distilled  water  efl'ected  a  thorough  cleansing  of  the 
interior  ])ortion  of  the  tooth,  it  should  next  be  dried  to  the  extent  of 
having  all  su])erfluous  moisture  removed,  and  it  will  then  be  in  condi- 
tion for  the  application  of  whatever  method  of  bleaching  may  be  chosen 
for  the  ])articular  case  in  hand. 

Dr.  James  Truman's  Method. — This,  as  before  stated,  Avas  the  first 
method  successfully  employed  for  bleaching  teeth.  It  consists  in  liberat- 
ing chlorin  from  ordinary  chlorinated  lime  by  means  of  a  weak  acid 


TOOTH-BLEACHING— USE  OF  CHLORIN.  535 

in  the  pulp  chamber  of  the  tooth.  Any  acid  will  effect  the  liberation  of 
chlorin  from  the  bleaching  powder,  but  acetic,  tartaric,  or  oxalic  are 
generally  used.  Care  must  be  observed  in  selecting  a  good  quality  of 
bleaching  powder,  as  that  substance  rapidly  undergoes  decomposition 
spontaneously,  especially  in  a  moist  atmosphere.  Good  chlorinated  lime 
is  a  dry  powder  having  a  strong  odor  of  chlorin.  If  it  is  moist  or  pasty 
and  has  but  a  feeble  odor  it  should  be  rejected  as  worthless.  Brands 
of  bleaching  powder  dispensed  in  metallic  packages  should  not  be  used, 
as  they  are  invariably  contaminated  with  metallic  chlorids  due  to  the 
slow  action  of  the  contents  upon  the  containing  package.  This  is  par- 
ticularly the  case  where  sheet-iron  boxes  are  used.  The  return  of  dis- 
coloration in  many  cases  after  bleaching  by  the  Truman  method  is 
undoubtedly  due  to  the  use  of  bleaching  powder  so  contaminated. 
The  powder  dispensed  in  glass  bottles  or  in  paraffined  paper  cartons 
is  more  reliable. 

Its  application  to  the  tooth  may  be  effected  in  several  ways  : 

(a)  By  packing  the  dry  powder  in  the  pulp  chamber  and  then  moist- 
ening the  latter  with  the  acid  ; 

(6)  By  mixing  the  powder  with  sufficient  distilled  water  to  make  a 
coherent  mass  which  is  more  easily  manipulated,  then  j)acking  it  in  the 
pulp  chamber  and  applying  the  acid  ; 

(c)  By  first  moistening  the  interior  of  the  tooth  with  the  acid,  next 
dipping  the  instrument  into  the  powder  and  then  into  the  acid,  each 
time  carrying  the  mixed  materials  into  the  tooth  until  the  desired 
change  of  color  is  produced. 

Probably  the  most  satisfactory  method  is  to  pack  the  dry  powder 
into  the  tooth  and  apply  the  acid  to  it,  after  which  immediately  seal  the 
cavity  with  a  single  pellet  of  gutta-percha.  By  using  a  50  per  cent, 
solution  of  acetic  acid  the  evolution  of  chlorin  will  take  place  with  a 
satisfactory  degree  of  uniformity,  and  not  so  rapidly  as  to  interfere  with 
its  penetration  throughout  the  discolored  tubular  structure  of  the  dentin. 
The  bleaching  mass  may  be  sealed  in  place  by  means  of  oxyphosphate 
of  zinc  if  desired,  but  it  is  usually  unnecessary  to  use  anything  other 
than  gutta-percha  or  one  of  the  soft  temporary  stopping  materials  for 
this  purpose. 

The  case  may  be  dismissed  for  one  or  two  days  and  the  treatment  as 
outlined  repeated  at  similar  intervals  until  the  tooth  is  restored  to 
normal  color. 

The  instruments  used  in  connection  with  this  process  should  be  of 
vulcanite,  bone,  ivory  or  wood.  Upon  no  consideration  should  steel, 
gold,  or  platinum  instruments  be  used,  as  chlorin  acts  directly  upon 
each  of  these  metals,  forming  soluble  chlorids  which  if  carried  into  the 
tooth  structure  will  give  rise  to  a  permanent  staining  of  most  intract- 


'hM)  I>rsCOl.ORi:i)    TKKTU  A.\I>    TUEIR    TREATMESr. 

:il>l('  cliarMctf  r.  Tlic  only  im-tals  wliicli  in:iy  he  salrly  used  in  connec- 
tion Avith  any  t-lilorin  process  of  hleacliinj;-  are  zinc  and  alnniinnni, 
the  chlorids  of  which  are  colorh'ss.  Ahiniinum  iiistrnnients  for  tlie 
pnrpose  may  he  (|uickly  improvised  out  of  wire  or  heavy  ])hite.  (n>ld 
instruments  have  heen  recommen(h'd,  hut  they  are  open  to  tlie  very 
ii:rave  ohji'ction  of  formini;  a  chh)rid  hy  (Hrec^t  cond)ination  with  chh>rin, 
which  salt  is  one  of  the  most  important  staining  media  known  to  the 
lii.stologist ;  as  a  matter  of  fact  the  writer  has  seen  several  cases 
where  a  permanent  purple  staining  of  the  tooth  has  resulted  from 
neglect  to  remove  gold  fillings  before  aj)plying  the  chlorin  method  of 
bleaching,  and  there  is  certainly  no  reason  why  the  same  result  should 
not  follow  the  using  of  gold  instruments  in  the  same  connection. 

M'hen  the  tooth  has  been  restored  to  its  proj)er  color  it  sh(ndd  be 
thoroughly  washed  with  very  hot  distilled  water,  dried  out  with  bibu- 
lous paper  and  thoroughly  desiccated  with  a  cui'i-ent  of  dry  hot  air, 
after  Avhich  the  canals,  pulp  chand)er,  and  cavities  should  be  tilled  with 
oxychlorid  of  zinc.^ 

The  final  filling  of  the  cavities  of  entrance  and  of  decay  should  be 
post})oned  until  by  a  la])se  of  considerable  time  the  j»ermanence  oi'  the 
operation  has  been  established.  This  probationary  period  may  with 
advantage  be  prolonged  to  four  or  six  months. 

The  final  washing  of  the  tooth  with  hot  distilled  water  previous  to 
the  insertion  of  the  zinc  oxychlorid  filling  is  a  feature  of  the  opera- 
tion which  requires  special  care  and  attention.  As  left  after  the  appli- 
cation of  the  bleaching  agent,  the  pulj)  chamber  and  canals  and  denti- 
nal structure  are  filled  with  free  chlorin  in  solution,  calcium  acetate,  or 
other  salt  of  calcium  dej)ending  upon  the  nature  of  the  acid  used  in 
the  process,  and  some  undecomposed  bleaching  powder.  These  sub- 
stances should  be  thoroughly  removed  by  the  hot-water  douche.  At 
least  a  pint  of  water  should  be  strongly  injected  into  the  interior  of  the 
tooth  by  means  of  a  large  bulb  syringe,  before  the  dam  is  removed.  A 
towel  held  in  close  proximity  to  the  tooth  will  catch  the  water  as  it  re- 
turns from  the  tooth  and  protect  the  clothing  of  the  patient.  Distilled 
water  should  in  all  cases  be  used  for  this  irrigating  douche,  as  river 
water  and  many  other  specimens  of  water  from  natural  sources  contain 
iron  in  solution,  which  could  readily  become  a  contaminating  factor 
leading  to  subsequent  return  of  discoloration. 

Ziuc  oxychlorid  is  selected  as  the  permanent  filling  for  the  pulp 
chamber  for  the  reason  that  it  is  necessary  to  so  act  upon  the  bleached 
organic  residuum  in  the  tubular  structure  as  to  ])revent  any  alteration 
of  its  character  which  may  result  in  the  i)roductiou  of  a  subsequent 
coloration.  Zinc  chlorid  ])ossesses  the  property  of  converting  many 
organic  substances  into  unalterable  compounds  by  its  coagulant  action, 


TOOTH-BLEACHING— USE  OF  CHLORTN.  537 

thus  tanning  or  mummifying  animal  tissue  and  preserving  it  indefi- 
nitely. A  mass  of  zinc  oxychlorid,  before  it  sets — i.  e.,  before  chemical 
combination  takes  place  between  the  zinc  oxid  powder  and  the  zinc 
chlorid  liquid,  is  functionally  free  zinc  chlorid — and  as  a  matter  of  fact 
the  properties  of  zinc  chlorid  are  manifested  by  such  a  mass  for  a  con- 
siderable period  of  time  after  the  mass  has  apparently  set.  When 
introduced  into  the  pulp  chamber  and  canal,  its  action  upon  the  organic 
debris  in  the  tubuli  is  as  stated,  and  the  material,  if  the  operation  has 
been  successfully  performed,  is  effectually  prevented  from  further  alter- 
ation, upon  which  condition  the  permanence  of  the  operation  depends. 

Another  method  for  preventing  subsequent  alteration  of  the  bleached 
organic  debris  in  the  tubular  structure  is  to  thoroughly  desiccate  the 
tooth  by  means  of  the  hot-air  blast  and  saturate  the  dentin  with  some 
insoluble  resinous  varnish,  such  as  copal  ether  varnish,  or  what  is  still 
better  the  solution  of  trinitrocellulose  in  methyl  alcohol,  known  in  com- 
merce as  "  kristaline  "  or  at  the  dental  depots  as  "  cavitine."  The 
pulp  chamber  and  canals  may  then  be  filled  with  any  suitable  filling. 

As  between  the  oxychlorid  of  zinc  filling  and  the  varnish  lining  the 
choice  in  general  should  be  of  the  former.  The  varnish  lining  is  adapt- 
able more  especially  to  cases  of  long  standing  where  complete  liquefac- 
tion of  the  tubular  contents  has  left  them  practically  empty,  and  where 
as  a  consequence  there  is  nothing  upon  which  zinc  chlorid  can  exert  its 
coagulating  effect. 

Other  Chlorin  Methods. — The  solution  of  chlorinated  soda  known 
as  Labarraque's  solution,  or  Liquor  sodse  chloratse  U.  S.  P.,  may  be 
applied  to  the  previously  desiccated  tooth  structure  until  the  dentin 
is  saturated  with  the  solution,  after  which  an  application  of  a  dilute 
acid  is  made  which  liberates  chlorin.  The  chemical  principles  in- 
volved are  exactly  analogous  to  those  upon  which  the  method  with 
bleaching  powder  depends,  the  only  difference  being  that  the  source 
of  the  active  agent,  chlorin,  is  in  one  case  its  calcium  compound,  which 
is  a  dry  powder,  and  in  the  second  case  the  analogous  soluble  sodium 
compound  of  chlorin  is  the  material  from  which  the  active  agent  is 
evolved. 

The  precautions  necessary  to  be  observed  are  exactly  the  same  as 
those  required  in  Truman's  method  already  described.  The  results 
obtained  by  this  process  are  not  as  thorough  or  as  satisfactory  as  by  the 
Truman  method. 

Chlorin  per  se  has  been  used  for  tooth-bleaching,  and  was  the  basis 
of  a  method  devised  by  Dr.  E.  P.  Wright  of  Richmond,  Va. 

"Wright's  method  involved  the  use  of  a  complicated  apparatus  by 
which  a  glass  vessel  of  about  a  half-liter  capacity,  and  filled  with  chlorin 
previously  prepared  in  the  laboratory,' was  connected  by  means  of  a. 


538  DISCOLORED   TEETH  AND   TJIF.IU    TnKATMI'XT. 

(loiiUly  perforated  rubber  stopper  and  two  pieces  of  rubber  tubiu^r  v^ith 
a  glass  ada})t('r,  around  the  open  end  of  which  was  tied  the  rubber  dam 
en(^irclino;  the  tooth  to  be  operated  u])on.  About  midMay  of  the  length 
of  one  of  the  rubber  tubes  councctiug  the  chlorin  reservoir  with  the 
rubber  (lam  was  interposed  an  ordinary  syringe  bulb,  so  arranged  with 
hard-rubbci-  valves  that  by  repeatedly  eoinpressing  and  relaxing  it  the 
chlorin  would  be  <lrawn  from  the  reservoir  and  injt'cti'd  through  a  glass 
delivery  jet  into  the  pulp  chamber.  Return  of  the  gas  to  the  reservoir 
was  provided  for  by  the  second  piece  of  rubber  tubing  first  alluded  to. 
In  this  way  a  continuous  jet  of  chlorin  was  thrown  into  and  about  the 
tooth,  which,  by  means  of  the  rubber  dam,  was  placed  in  a  close  cham- 
ber forming  a  part  of  the  apparatus  ;  none  of  the  gas  could  escape  into 
the  surrounding  atmosphere.  The  complexity  of  the  apparatus  was 
a  formidable  obstacle  to  the  general  use  of  the  method  and  it  was 
abandoned,  though  the  results  were  in  many  cases  very  satisfactory. 

The  Dioxid  Bleaching  Methods. 

Bleaching  by  Means  of  the  Dioxid  of  Hydrogen  and  the  Dioxid 
of  Sodium. — The  commercial  introduction  of  solutions  of  hydrogen 
dioxid  marked  a  new  era  in  the  operation  of  bleaching  discolored  teeth. 
The  bleaching  property  of  hydrogen  dioxid  had  been  known  to  chemists 
for  many  vears,  but  the  application  of  this  property  to  tooth-bleaching 
dates  from  the  medicinal  use  of  hydrogen  dioxid  solutions  for  the  treat- 
ment of  purulent  conditions  of  the  pulp  canal  and  about  the  roots  of 
teeth.  \Vhen  applied  in  the  canals  of  discolored  and  infected  teeth  it 
was  observed  that  a  noticeable  bleaching  of  the  discolored  structure 
resulted.  The  hint  thus  given  was  further  studied  until  it  was  found 
that  under  proper  conditions  the  whole  structure  of  a  discolored  tooth 
might  be  successfidly  restored  to  normal  color. 

The  earlier  preparations  were  found  to  be  lacking  in  strength ; 
aqueous  solutions  containing  more  than  3  or  4  per  cent,  of  absolute 
hydrogen  dioxid  were  found  to  be  too  unstable  to  keep  for  any  length 
of  time,  and  hence  were  unreliable.  The  problem  of  securing  a  stable 
high-percentage  solution  of  the  dioxid  was  solved  by  using  ether  as  a 
menstruum,  and  the  25  per  cent,  solution  of  hydrogen  dioxid  made  by 
INIcKesson  &  Robbins  of  New  York  and  sold  as  "  caustic  pyrozone " 
is  now  generally  used  where  hydrogen  dioxid  is  employed  as  a  bleaching 
agent  in  connection  with  discolored  tooth  structure. 

Hydrogen  dioxid,  H.,0,.,  belongs  to  the  class  of  "  oxidizing  bleach- 
ers," and  owes  its  activity  in  this  respect  to  the  weak  state  of  chemical 
combination  in  which  one  of  its  atoms  of  oxygen  is  bound  to  the  water 
molecule.  jNIany  substances  serve  to  disrupt  the  compound  and  liber- 
ate one  of  its  oxygen  atoms.     In  contact  with   pus,  blood,  inspissated 


BLEACHING  BY  HYDROGEN  DIOXID.  539 

mucus,  albumin,  and  in  fact  almost  every  kind  of  dead  organic  matter, 
its  decomposition  takes  place,  evolving  oxygen  and  decomposing  the 
organic  matter  either  wholly  or  in  part.  Hydrogen  dioxid  does  not 
bleach  all  of  the  decomposition-products  of  hemoglobin  with  equal 
facility.  It  quickly  removes  the  pink  discoloration  following  the  initial 
extravasation  of  hemoglobin  into  the  dentin,  but  when  the  brown  stage 
has  been  reached  indicative  of  the  formation  of  hematin  its  action  is  but 
slight.  Later,  however,  it  bleaches  more  readily.  Tlie  refractory 
nature  of  hematin  with  respect  to  hydrogen  dioxid  has  been  experimen- 
tally tested  upon  the  substance  out  of  the  mouth. 

In  bleaching  discolored  teeth  with  hydrogen  dioxid  the  ethereal  25 
per  cent,  solution  known  as  pyrozone  is  directly  applied  to  the  internal 
portions  of  the  tooth  upon  small  pledgets  of  cotton  or  cotton  wisps 
rolled  upon  a  fine  flexible  canal  instrument.  After  each  application 
the  ethereal  menstruum  is  evaporated  by  blasts  of  warmed  air  from  a 
hot-air  syringe,  and  the  applications  similarly  made  are  repeated  until 
the  desired  eifect  is  produced.  It  has  been  found  in  practice  that  more 
rapid  and  permanent  effects  are  produced  when  the  pyrozone  solution 
is  rendered  alkaline.  This  may  be  readily  done  by  the  addition  of  a 
few  drops  of  liquor  ammonise  fortior  or  by  a  solution  of  one  of  the 
caustic  alkalies,  e.g.  sodium  or  potassium  hydroxid  or  sodium  dioxid. 
A  very  satisfactory  method  of  securing  the  alkaline  effect  in  this  pro- 
cess is  that  suggested  by  Dr.  D.  N.  McQuillen.  His  method  is  to 
first  treat  the  pulp  chamber  and  canals  with  applications  of  Schreier's 
Kalium-natrium  preparation  and  after  the  debris  from  its  action  has 
been  mechanically  removed  with  instruments  and  cotton  twists,  with- 
out washing  the  canal,  an  application  of  pyrozone  is  made.  The 
bleaching  action  follows  with  great  rapidity,  and  has  apparently  greater 
permanence  than  where  the  pyrozone  is  used  alone.  In  cases  where 
the  action  proceeds  very  slowly,  for  example  when  at  the  end  of  a  thirty 
minutes'  continuous  treatment  the  bleaching  is  not  complete,  it  is  well 
to  seal  an  application  of  pyrozone  upon  cotton  in  the  canal  and  allow  it 
to  remain  for  twenty-four  hours,  when  a  second  treatment  will  usually 
complete  the  operation. 

In  this  as  in  all  bleaching  operations  it  is  advisable  to  fill  the  tooth 
temporarily  with  some  easily  removable  filling  in  order  to  test  the  per- 
manence of  the  operation,  and  after  the  lapse  of  a  reasonable  time  if 
there  is  no  tendency  to  a  return  of  the  discoloration  the  canals  and 
cavity  may  be  permanently  filled. 

Dr.  Harlan's  method  consists  in  acting  upon  hydrogen  dioxid  by 
aluminum  chlorid.  The  aluminum  salt  is  packed  in  the  cavity  and 
moistened  with  the  dioxid.  The  technique  of  the  procedure  is  the 
same  as  for  the  methods  already  described.     This  process  was  origin- 


;")4()  DISCOLORED   TKKTH  AND   Til  KIR    TREATMENT. 

allv  t'lassilitMl  with  tlio  fliloriii  inctlxMls,  as  the  tkn'omposition  was  sup- 
posed to  take  \)\[wv  accortlinj^  to  tlic  tullowin<;  cipiatiou  : 

\\X\   I   3H.p.,  =  ALO3  +  3H,0  +  6C1. 

Experimental  study  of  tlic  reaction  between  aluminum  chlorid  and 
hydrogen  dioxid  hy  the  writer  developed  the  fact  that  oxygen  and  not 
cidorin  was  given  off,  and  that  the  aluminum  chlorid  was  unaltered 
during  the  process.  Hence  it  w^as  discovered  that  the  reaction  was 
simply  due  to  a  catalytic  action  of  the  aluminum  salt  (a  property 
wliich  in  this  relation  it  shares  in  common  with  many  other  metallic 
salts),  whereby  nascent  oxygen  is  liberated  from  the  hydrogen  dioxid. 
The  process,  therefore,  has  no  greater  value  than  those  in  which  hydro- 
gen dioxid  is  directly  applied.  The  aluminum  chlorid  being  an  active 
coagulant  is  contraindicated  as  a  factor  in  the  l)leaching  process  until 
a  point  lias  been  reached  where  a  coagulant  is  needed  as  a  fixative  after 
the  bleaching  has  been  etiected. 

The  Sodium  Dioxid  Method. — Sodium  dioxid,  Na^O^,  is  the  chem- 
ical analogue  of  hydrogen  dioxid,  and  like  the  latter  is  characterized 
by  the  readiness  with  which  it  parts  with  its  atom  of  loosely  com- 
bined oxygen  under  similar  circumstances.  The  essential  difference  in 
its  properties  is  the  character  of  its  by-product  after  its  decomposition 
has  taken  place.  Itself  a  strong  caustic  alkali,  it  still  retains  its  alka- 
line and  caustic  properties  after  the  loss  of  one  of  its  atoms  of  oxygen, 
becoming  NajO,  which  in  combination  with  water  is  ordinary  sodium 
hydroxid  or  caustic  soda.  This  substance  as  well  as  the  sodium  dioxid 
has  not  only  a  saponifying  property  for  all  of  the  vegetable  and  animal 
oils  and  fats,  but  also  a  solvent  action  upon  animal  tissue.  This  property 
is  of  great  value  in  removing  from  the  dentin  structure  all  of  the  con- 
tained organic  matter,  whether  normal  or  in  a  state  of  decomposition. 
Having  the  oxidizing  and  consequently  the  bleaching  quality  in  addi- 
tion to  its  solvent  and  saponifying  properties  it  is,  therefore,  one  of  the 
most  valuable  bleaching  and  detergent  agents  at  our  command.  The 
substance  is  dispensed  as  a  yellowish  white  powder  in  tin  cans  or 
glass  bottles  hermetically  sealed,  as  it  is  very  hygroscopic  and  after 
twenty-four  hours'  exposure  to  moist  air  absorbs  nearly  its  own  weight 
of  water  ;  it  also  loses  much  of  its  activity. 

For  use  as  a  bleaching  agent  it  is  applied  to  the  dentin  in  saturated 
solution.  In  making  the  solution  especial  care  is  necessary  in  order  to 
avoid  elevation  of  temperature,  by  reason  of  the  energy  with  which  it 
enters  into  combination  with  the  water.  If  the  solution  is  allowed 
to  become  heated  in  the  making,  decomposition  of  the  compound  with 
loss  of  oxygen   occurs  and   its  bleaching   power    is    destroyed.      The 


BLEACHING  BY  SODIUM  DIOXID.  541 

solution  is  best  made  by  pouring  into  a  small  beaker  of  about  one 
ounce  capacity  about  two  drachms  of  distilled  water,  and  immersing  the 
beaker  in  a  larger  vessel  or  dish  containing  ice-water  or  pounded  ice. 
The  can  containing  the  dioxid  powder  should  then  have  its  lid  per- 
forated with  a  number  of  small  holes  similar  to  the  lid  of  a  pepper 
caster,  and  the  powder  be  slowly  dusted  into  the  distilled  water  in  the 
small  beaker ;  or  the  powder  may  be  gradually  dropped  into  the  water 
by  tapping  it  from  the  point  of  a  knife  or  spatula.  The  powder  is 
added  to  the  water  until  the  solution  assumes  a  semi-opaque  appearance, 
indicating  the  point  of  saturation.  On  removing  the  beaker  from  the 
cooling  mixture,  the  dioxid  solution  will  in  a  few  minutes  assume  a 
transparent,  straw-colored  appearance   and  is  ready  for  use. 

The  applications  are  to  be  made  similarly  to  the  hydrogen  dioxid 
applications,  but  upon  asbestos  fiber  instead  of  cotton,  as  the  latter  is 
acted  upon  by  the  sodium  dioxid  and  converted  into  a  glue-like  mate- 
rial, amyloid,  which  is  difficult  to  remove  and  interferes  with  the  suc- 
cess of  the  operation. 

After  the  dentin,  which  should  have  been  previously  desiccated,  is 
thoroughly  saturated  with  the  dioxid  solution  an  application  of  10  per 
cent,  sulfuric  acid  should  be  made,  which  neutralizes  the  strong  alkali, 
forming  sodium  sulfate  and  hydrogen  dioxid,  thus  : 


Na202  +  H2SO,  =  Na^SO^  +  H^O, 


The  reaction  is  usually  attended  with  some  effervescence,  which  taking 
place  in  the  tubular  structure  of  the  dentin,  mechanically  forces  out  its 
contents  and  thus  exerts  a  detergent  action  upon  it.  The  tooth  should 
now  be  washed  with  hot  distilled  water  in  copious  quantity  and  the 
dioxid  application  repeated,  omitting  the  subsequent  treatment  with 
acid  but  washing  again  thoroughly  with  the  hot  water. 

Sodium  dioxid  solution,  as  prepared  for  bleaching,  may  be  applied 
to  the  pulp  chamber  and  root  canal  without  the  preliminary  treatment 
required  where  other  bleaching  agents  are  employed.  It  is  Avithout 
harmful  irritative  action  upon  the  apical  tissues  unless  used  in  excess 
or  forced  through  the  foramen  by  careless  manipulation.  It  is  a  power- 
ful germicide  and  disinfectant,  and  therefore  peculiarly  suited  to  the 
treatment  of  putrescent  cases,  which  by  its  action  are  rendered  sterile 
and  aseptic  as  well  as  bleached  at  one  operation.  Its  saponifying  and 
solvent  properties  completely  remove  the  greasy  dark  layer  of  decom- 
posed material  which  is  found  lining  the  pulp  chamber  and  canals 
alluded  to  on  page  546,  so  that  the  use  of  the  sodium  dioxid  method 
makes  unnecessary  the  application  of  borax  or  ammonia  for  its  removal 
as  a  preliminary.      When  used  for  its  sterilizing  property  the  foramen 


642  DISCOLORED  TEETH  AND   THEIR   TREATMENT. 

should  be  allowed  to  remain  unsealed  until  after  the  bleaching  operation 
ha.s  been  completed.  It  sometimes  happens  that  the  improvement  in 
color  follo\vin<;  tiio  application  of  the  dioxid  methods  is  only  partial 
and  the  result  falls  short  of  restoration  to  normal ;  or,  in  other  words, 
the  bleaching  reaches  a  certain  point  bovond  which  the  color  resists  the 
further  action  of  the  bleaching  agent.  In  such  cases  the  decomposition 
of  the  color  molecule  has  probably  resulted  in  the  formation  of  iron 
oxid  as  an  end-product.  In  practice  this  residual  discoloration  can 
generally  be  removed  by  treatment  with  oxalic  acid.  A  small  crystal 
is  to  be  sealed  in  the  moist  pulp  chamber  for  twenty-four  hours, 
and  afterward  washed  out  with  a  copious  irrigation  of  hot  distilled 
water. 

The  sodium  dioxid  method  removes  more  completely  than  any 
other  the  tubular  contents,  and  the  result  is  unique  from  the  fact 
that  not  only  is  the  tooth  restored  to  normal  color  but  to  normal 
translucency  ;  the  opaque  white  effect  resulting  from  other  methods 
of  bleaching  is  due  to  the  bleached  organic  debris  remaining  in  the 
tubuli,  but  by  the  solvent  action  of  the  strong  caustic  alkali  this  is 
removed.  The  final  treatment  of  the  tooth  is  the  same  in  this  as  in 
other  methods,  though  the  dentin  should  be  desiccated  and  saturated 
as  thoroughly  as  possible  with  an  unalterable  varnish  before  the  final 
filling  is  inserted. 

The  Sulfurous  Acid  Method. — Reference  has  already  been  made 
to  sulfurous  acid  as  the  single  example  of  the  reducing  type  of  bleach- 
ing agent.  Its  activity  is  due  to  its  affinity  for  oxygen,  and  it  bleaches 
by  seizing  upon  and  combining  with  that  element  of  the  color  molecule, 
thus  destroying  its  identity  and  consequently  its  color.  Attempts  have 
been  made  to  utilize  the  bleaching  property  of  sulfurous  acid  in  the 
treatment  of  discolored  teeth  by  direct  apjdications  of  the  solution  of  the 
gas  in  water  and  by  igniting  small  quantities  of  sulfur  in  the  root  canal 
by  means  of  the  electro-cautery  Avire.  These  methods  have,  however, 
proved  inefficient.  The  gas  may  be  successfully  used  in  bleaching  teeth 
by  evolving  it  from  its  compounds  placed  in  the  cavity  and  root  canal 
in  a  manner  analogous  to  that  employed  in  the  Truman  chlorin  process 
already  described.  For  this  purpose  the  writer's  method  may  be  con- 
veniently employed  :  100  grains  of  sodium  sulfite  and  70  grains  of 
boric  acid  are  separately  desiccated  and  afterward  ground  together  in  p 
warm  dry  mortar.  The  powder  is  then  to  be  transferred  to  a  tightly 
stoppered  bottle.  For  bleaching  purposes  the  powder  is  packed  into  the 
root  canal  and  cavity  of  the  tooth,  and  then  moistened  with  a  drop  of 
water  and  the  cavity  immediately  closed  as  tightly  as  possible  with  a 
stopping  of  gutta-percha  previously  prepared  and  warmed.     A  reaction 


CATAPHORIC  BLEACHING  OF  TEETH.  543 

ensues  between  the  boric  acid  and  sodium  sulfite  whereby  sulfurous 
acid  is  liberated^  thus  : 

2H3BO3  +  3Na,S03  =  2Na3B03  +  SH^O  +3SO,. 

The  process  is  effective  in  many  cases  where  the  chlorin  methods  have 
failed,  but  is  slow  in  its  action  and  i-s  largely  superseded  by  the  dioxid- 
of-hydrogen  and  dioxid-of-sodium  methods. 

Cataphoric  Bleaching  op  Teeth. 

Since  the  revival  of  interest  in  cataphoresis  and  its  application  to 
dental  operations  its  possibilities  as  an  adjuvant  in  the  tooth-bleaching 
process  are  being  investigated  with  much  promise  of  valuable  results. 
It  has  been  found  that  aqueous  solutions  of  hydrogen  dioxid  may  be  car- 
ried into  the  dentinal  structure  with  great  ease  by  the  cataphoric  action 
of  the  continuous  current.  The  appliances  necessary  for  tooth-bleaching 
operations  by  this  means  are  practically  the  same  as  those  required  in  the 
treatment  of  hypersensitive  dentin,  and  are  detailed  at  length  in  the 
chapter  dealing  with  that  subject  (page  189).  The  resistance  offered  by 
the  hard  structures  of  the  tooth  is  much  greater  after  loss  of  the  tooth 
pulp,  requiring  a  much  higher  voltage  pressure  to  drive  the  bleaching 
agent  into  the  tissue.  While  in  some  cases  25  to  30  volts  will  be  all 
that  is  necessary,  some  cases  will  require  as  high  as  60  volts  to  carry 
1.5  milliamperes  of  current  through  the  dentin.  The  ethereal  solution 
of  hydrogen  dioxid  has  been  found  to  oppose  too  great  resistance  to 
the  current,  but  the  aqueous  solution  containing  a  slight  addition  of 
some  salt  to  increase  its  conductivity  is  entirely  manageable. 

A  25  per  cent,  aqueous  solution  of  hydrogen  dioxid  may  be  quickly 
made  by  shaking  together  in  a  test  tube  one  volume  of  water  and  two 
volumes  of  25  per  cent,  pyrozone.  The  HgOj  dissolves  in  the  water, 
and  the  ether  of  the  pyrozone  may  be  removed  by  pouring  the  mixture 
into  a  small  evaporating  dish  of  porcelain  or  glass  and  gently  heating  it 
over  a  water  bath  until  all  of  the  ether  has  evaporated.  The.  addition 
of  a  small  quantity  of  sodium  acetate  or  sulfate  will  greatly  diminish 
the  resistance  of  the  solution  to  the  passage  of  the  current. 

With  the  tooth  isolated  by  the  rubber  dam  and  having  received  the 
treatment  preliminary  to  bleaching,  as  already  described  in  detail,  the 
aqueous  solution  of  H0O2  is  dropped  upon  cotton  within  the  tooth 
cavity  and  a  platinum  needle  anode  is  applied  in  contact  with  it. 
The  cathode  may  be  a  sponge  electrode  moistened  with  salt  solution  and 
held  in  the  hand  or  applied  to  the  cheek  or  neck.  The  hand,  howe^ver, 
is  preferable  because  of  the  amount  of  voltage  required  in  the  operation. 
Great  care  must  be  exercised  that  the  external  surfaces  of  the  tooth  are 


544  DISCOLORED   TEETH  AND   THEIR   TIIKATMI.ST. 

kept  dry  so  that  slHU't-circiiiting  of  tlic  ciirfcnt  iiiav  nut  take  place.  In 
some  oases  a  more  raj)i(l  effect  is  ohtained  hy  niakiiit;  contact  of  the 
cathode  pole  thrcMigh  a  needle  electrode  upon  the  external  snrfaceof  the 
tooth,  and  \\\\\\  the  anode  applied  to  the  jnrozone  solution  on  cotton 
Avithin  the  tooth.  The  cotton  must  at  all  times  he  kept  wet  Avith  the 
solution. 

The  arrangement  of  the  electrical  terminals  with  respect  to  the 
bleaching  operation  is  both  theoretically  and  practically  correct  as  de- 
scribed, viz.  the  flow  of  current  shoukl  be  from  the  anode  point  through 
the  bleaching  solution  and  tooth  and  the  body  of  the  patient  to  the 
cathode.  In  |)ractice  it  has  been  found  in  some  cases  which  have  failed 
to  bleach  with  the  elements  arranged  in  the  series  as  stated,  that  upon 
reversing  the  poles  and  direction  of  current  flow  the  bleaching  has 
rapidly  followed.  The  explanation  of  this  apparent  paradox  is  that 
by  the  application  in  normal  order  ILO^  was  first  carried  into  the 
tubular  structure,  and  the  reversal  of  the  current  has  acted  upon  the 
tubular  contents  now  saturated  with  the  dioxid,  and  by  its  jiropulsive 
as  well  as  electrolytic  effect  removed  the  pigmentary  matter  pulpward 
from  the  tubidi.  Bleaching  with  reversed  poles  woidd  be  impossible 
without  previous  saturation  of  the  dentin  by  the  dioxid  solution. 

Dr.  ]\r.  W.  Holling^worth  has  devised  an  ingenious  anode  for  feed- 
ing the  bleaching  solution  or  other  medicament  into  the  cavity  as  de- 
sired.    The  instrument  (Fig.  109)  is  described  in  Chapter  VI. 

Another  device  by  Dr.  Hollingsworth  is  of  es])ecial  value,  as  it 
makes  possible  the  enveloping  of  the  entire  tooth  with  the  bleaching 
fluid  in  which  it  is  immersed  as  in  a  bath.     The  appliance  is  shown  in 

Fig.  469. 


Dr.  Hollingswortli's  device  for  applying  the  bleaching  agent  to  the  tooth. 

situ  in  k'ig.  4Gf»,  and  consists  of  a  thin  vulcanized  caout<-lionc  l)Mlb 
shaped  like  the  bulb  of  a  medicine  dropper.  Through  a  perforation 
at  its  rounded  end  made  with  the  ordinary  rubber  dam  punch,  the 
tooth  is  slipped  by  mounting  the  bulb  on  the  applicator  (Fig.  470),  and 


CATAPHORIC  BLEACHING   OF  TEETH.  545 

forcing  it  over  the  tooth  as  though  it  were  a  rubber  dam.    A  glass  tube 

Fig.  470. 


is  then  attached  to  the  open  end  of  the  bulb,  and  to  the  glass  tube  is 
connected  a  spiral  platinum  wire  electrode  (Fig.  471).    Before  the  elec- 


FiG.  471. 


Tube  electrode. 


trode  is  attached  the  bulb  and  glass  tube  are  completely  filled  with  the 
aqueous  pyrozone  solution  by  means  of  a  duplex  syringe  (Fig.  472),  the 


Fig.  472. 


Duplex  syringe. 


lower  and  larger  bulb  of  which  exhausts  the  contained  air  in  the  appa- 
ratus and  the  smaller  thumb  bulb  injects  the  bleaching  solution  into  the 
exhausted  apparatus.     Connection  is  now  made  with  the  source  of  cur- 

35 


r)4G  DISCOLORED   TEETH  AND   THEIR   TREATMENT. 

rout  as  usual,  aud  tlic  hlcadiiuu-  is  very  rapidly  cITcclcd.  Dr.  Hol- 
lintisworth  rccoiiuut'nds  llic  addition  ol"  about  1  |K'r  cent,  of"  /iuc  sulfate 
to  the  a(|U(M)Us  pyro/ouc  solution,  w  liicli  not  only  diniiuislics  the  rcsist- 
anco  to  the  ])assa<^i'  of  tlu'  current,  hut  has  a  coaj^idating  ctt'cct  upon 
the  hlcachcd  organic  matter  which  oives  it  translucency  and  greatly 
enhauiH's  the  perinanency  of  the  operation.  The  results  obtained  by 
this  method  are  extremely  satisfactory. 

Bleaching  Methods  for  Special  Stains. 

Pulpless  teeth  are  especially  liable  to  discoloration  from  external  and 
accidental  causes.  If  decayeil  and  the  cavity  has  remained  unfilled  for 
a  length  of  time  many  substances  which  find  their  way  into  the  oral 
cavity  either  as  food  or  as  medicine  may  produce  discoloration  when 
absorbed  by  the  tooth  through  the  open  cavity  walls. 

Metallic  salts  arc  particularly  apt  to  cause  such  staining  by  reaction 
with  the  sulfids  Avith  which  the  dentin  structure  is  usually  saturated 
during  decomposition  of  its  organic  contents.  INIauy  of  the  medica- 
ments used  in  pulp-canal  treatment  or  even  for  hypersensitive  dentin 
may  stain  the  tooth  structure,  and  finally  the  action  of  sulfids  in  the 
structure  of  a  pulpless  tooth  may  react  with  amalgam  fillings,  forming 
salts  of  mercury,  silver,  tin,  copper,  etc.,  which  are  absorbed  by  the 
tooth,  resulting  in  its  discoloration.  The  treatment  of  these  stains, 
which  were  grouped  as  Class  III.  at  the  beginning  of  this  chapter, 
is  extremely  difficult  and  often  unsatisfactory.  However,  there  may 
arise  individual  cases  of  discolorations  of  this  class  where  it  is  of  the 
utmost  iinj)()rtance  to  remove  them,  and  much  may  often  be  accom- 
])lished  when  the  causes  of  the  discoloration  are  known  and  the  proper 
bleaching  method  is  applied. 

Gold  stains  may  arise,  as  has  been  already  indicated,  from  the  inju- 
dicious use  of  gold  instruments  or  failure  to  remove  all  gold  fillings 
when  applying  some  one  of  the  chlorin  methods  of  bleaching.  In  the 
course  of  time  where  this  has  happened  the  tooth  assumes  a  pinkish 
hue  which  merges  into  a  characteristic  violet  or  purple,  finally  becom- 
ing black. 

Iron  stains  may  arise  from  the  use  of  steel  instruments  in  connection 
with  the  chlorin  methods  of  bleaching  or  in  contact  Avith  iodin  or  any 
of  the  mineral  acids  in  connection  \vith  canal  treatment.  The  iron 
stain  is  yellowish  at  first,  gradually  becoming  brown  and  finally  black. 

Copper  and  nickel  stains  may  arise  from  contact  with  these  metals 
or  their  alloys,  as  copper  amalgam  or  nickel  or  German  silver 
dowels  for  artificial  crowns  or  anchorages  for  fillings.  The  stains 
from  those  metals  are — for  copper,  bluish  to  black,  and  for  nickel  a 
characteristic  chlorophyll  crreen  wdiich  eventually  becomes  black. 


BLEACHING  METHODS  FOR  SPECIAL  STAINS.  547 

The  best  general  treatment  for  all  of  the  foregoing  stains  is  to 
re-bleach  the  tooth  by  the  chlorin  method,  with  especial  care  as  to  the 
several  precautions  already  recommended,  and  when  the  color  of  the 
metallic  stain  has  been  discharged  by  conversion  of  the  dark-colored 
salt  into  a  soluble  chlorid,  wash  the  tooth  thoroughly  first  with  dilute 
chlorin  Avater  50  per  cent.,  and  afterward  with  hot  distilled  water  to 
remove  all  of  the  metallic  chlorid  which  has  been  formed.  The  process 
may  require  rej^etition  to  secure  permanent  results. 

Silver  stains  are  comparatively  easy  to  remove,  either  by  an  applica- 
tion of  the  chlorin  method  or  by  saturating  the  tooth  with  tincture  of 
iodin,  thus  converting  the  silver  salt  into  a  chlorid  or  iodid  as  the  case 
may  be,  after  which  it  may  be  dissolved  out  with  a  saturated  solution 
of  sodium  hyposulfite  applied  as  a  bath  to  the  tooth.  For  this  pur- 
pose the  Hollingsworth  bulb  dam  (see  Fig.  471)  answers  admirably, 
and  although  the  experiment  has  not  as  yet  been  tried,  there  is  good 
reason  to  believe  that  the  cataphoric  method  with  electrodes  applied  in 
reverse  order  would  under  these  circumstances  greatly  facilitate  the 
solution  and  removal  of  the  metallic  salts. 

Mercurial  stains  are  always  black  from  the  formation  of  mercuric 
sulfid,  and  are  removable  by  the  same  method  as  are  silver  stains,  with 
the  exception  that  where  the  stain  has  been  converted  into  a  chlorid 
by  the  chlorin  method,  the  mercuric  chlorid  is  best  removed  by  an 
aqueous  ammoniacal  solution  of  hydrogen  dioxid,  or  when  the  stain 
has  been  converted  into  mercuric  iodid  by  the  use  of  a  saturated  solu- 
tion of  potassium  iodid.  In  both  cases  a  final  washing  with  hot  dis- 
tilled water  is  a  sine  qua  non. 

Manganese  stains  frequently  occur  from  the  use  of  potassium  per- 
manganate, in  solution  or  in  substance,  in  the  treatment  of  putrescent 
canal  conditions.  The  manganese  stain  is  a  characteristic  mahogany 
brown.  It  is  very  readily  removed  by  a  25  per  cent,  aqueous  solution 
of  hydrogen  dioxid  in  which  oxalic  acid  crystals  have  been  dissolved 
to  saturation.  A  few  applications  of  this  mixture  will  quickly  de- 
colorize the  stain,  after  which  a  liberal  treatment  of  hot  distilled  water 
is  required  as  in  the  foregoing  cases. 

In  all  cases  a  careful  diagnosis  of  the  chemical  nature  of  the  dis- 
coloration should  be  made  when  possible.  Much  information  upon  this 
point  may  be  gained  by  a  detailed  study  of  the  present  condition  of  the 
tooth  and  its  environment,  but  in  addition  to  this  the  patient  should  be 
questioned  as  to  the  history  of  the  case,  and  especially  as  to  its  previous 
treatment.  The  data  thus  obtained  should  be  carefully  noted  and  treat- 
ment instituted  in  accordance  with  the  conditions  to  be  met. 

Success  in  the  bleaching  of  teeth  demands  a  recognition  of  the  fact 
that  each  case  presents   individual  peculiarities,  that  the  problem  is 


548  DISCOLORED   TEETH  AXD   THEIR   TREATMENT. 

essentially  a  ehemieal  one  always,  and  that  the  bleaeliintr  method  in  any 
given  ease  must  be  selected  with  esjK'eiul  reference  to  the  character  of 
the  discoloration  and  a])i>lied  with  due  care  as  to  its  details  in  order  that 
the  chemical  re(iuirements  of  the  operation  may  be  intelligently  met ; 
without  which  care  success  is  impossible. 


CHAPTER    XXI. 

EXTRACTION  OF  TEETH. 

By  M.  H.  Cryer,  M.  D.,  D.  D.  S. 


Indications  for  the  Operation. 

It  is  impossible  to  formulate  a  set  of  exact  rules  by  which  the  prac- 
titioner may  be  governed,  in  deciding  upon  the  extraction  of  teeth.  So 
many  circumstances  both  local  and  general  must  be  taken  into  consid- 
eration that  little  more  can  be  done  than  to  suggest  the  most  important 
causes  which  demand  the  operation. 

Deciduous  Teeth. — The  indications  for  extracting  deciduous  teeth 
are — 

First :  When  the  teeth  are  a  source  of  irritation  affecting  the  gen- 
eral health  or  comfort  of  the  child  and  do  not  respond  to  treatment. 

Second  :  When  the  deciduous  teeth  are  preventing  the  eruption  of 
the  permanent  teeth  into  their  normal  positions.  Occasionally  a  de- 
ciduous tooth  will  assist  in  the  proper  placing  of  a  permanent  one, 
in  which  case  it  should  not  be  removed  as  long  as  it  is  of  such 
use. 

Third  :  When  a  lower  permanent  incisor  shows  signs  of  erupting  on 
the  labial  side  of  the  deciduous  tooth,  the  latter  should  be  removed  at 
once,  but  if  the  erupting  tooth  appears  on  the  lingual  side  the  removal 
of  the  deciduous  tooth  may  in  that  case  be  delayed  somewhat  longer. 

Fourth  :  When  upper  permanent  incisors  show  a  tendency  to  erupt 
on  the  palatal  side  of  the  temporary  teeth,  the  latter  should  be  extracted, 
but  when  they  are  erupting  on  the  labial  side  the  deciduous  teeth  may 
be  allowed  to  remain  for  a  time,  as  they  are  often  useful  in  forcing  the 
permanent  teeth  outwardly.  This,  however,  must  be  closely  watched 
to  prevent  the  permanent  incisors  from  moving  too  far. 

Permanent  Teeth. — The  indications  for  extraction  of  the  permanent 
teeth  are — 

First :  Diseased  roots  which  cannot  be  cured  and  so  made  useful 
for  crowning,  or  assisting  in  retaining  a  bridge,  plate,  or  other  pros- 
thetic device. 

549 


550  EXTRACTION  OF   TEETH. 

Second  :  Tcotli  of  mastication  that  have  h)st  their  ocehuliiijz:  teeth 
and  in  consequence  there(»f  are  heinoi;  pushed  from  their  alveoli  and  are 
a  source  of  troul)le.  ,\s  a  rule,  this  relcrs  only  to  the  second  or  third 
molars,  and  more  particularly  to  tlu'  third  molar.  M'hen  it  occurs  with 
other  teeth  the  opposite  vacant  space  should  be  tilled  l»y  an  artificial 
tooth  to  jirevent  the  extrusion  of  the  natural   tooth. 

Third  :  When  ineurahle  abseesses  originatintr  from  tet'th  in  the 
upper  jaw  tend  to  open  into  the  nasal  chamber,  maxillary  sinus,  or 
zvgomatie  fossa,  the  teeth  associated  with  such  abscesses  should  be  ex- 
tracted. When  diseased  teeth  are  the  exciting  cause  of  an  incurable  ab- 
scess in  the  lower  jaw  which  opens  or  threatens  to  open  externally  on 
the  chin,  jaw,  or  below  the  bone  into  or  upon  the  neck,  they  should  be 
removed. 

Fourth  :  Teeth  which  occupy  irregular  ])ositions  in  the  arch,  that 
cannot  be  corrected  so  as  to  become  useful  or  contribute  to  the  gen- 
eral symmetry  of  the  mouth,  should  be  removed. 

Fifth  :  Elrupting  teeth  that  are  retarded  because  of  lack  of  room 
in  the  jaw,  if  giving  pain,  should  be  extracted  or  else  the  tooth  that  is 
preventing  the  eruption  shoidd  be  removed.  A  marked  exam])le  of 
this  is  often  found  in  the  eruption  of  the  third  molar  when  all  the  other 
teeth  are  of  good  size  and  are  in  place.  These  molars  when  retarded 
often  cause  the  greatest  distress,  sometimes  producing  serious  results,  and 
must  then  be  extracted  ;  if  they  cannot  l)e  safely  removed  the  second  molar 
may  be  extracted,  in  consequence  of  which  the  third  molar  will  usually 
be  erupted  near  its  place.  When  an  upper  third  molar  is  erupting 
under  the  same  circumstances  there  is  usually  less  difficulty,  as  having 
but  slight  resistance  distally  it  can  erupt  outwardly  or  slightly  back- 
ward, though,  should  it  impinge  upon  the  soft  tissues  covering  the  ramus 
of  the  lower  jaw,  it  should  be  extracted. 

Sixth  :  Teeth  so  badly  diseased  that  they  will  not  respond  to  treat- 
ment and  are  a  source  of  discomfort  to  the  patient  should  be  removed, 
as  thev  impair  the  general  health. 

Seventh  :  Fird  molars.  There  has  been  much  discussion  regarding 
the  early  extraction  of  these  teeth,  many  claiming  that  if  the  pulp  of 
one  becomes  devitalized  at  an  early  period  of  life  and  it  is  deemed  best 
to  extract  it,  the  other  three  should  also  be  removed.  No  fixed  general 
rule,  however,  can  be  given  ;  each  case  must  be  considered  separately. 
There  are  cases  where  the  extraction  of  all  is  necessary,  and  others 
where  it  would  be  a  most  unwise  thing  to  do.  When  the  anterior  teeth 
are  fully  in  position,  the  bicuspids  occluding  correctly  and  the  second 
molars  are  about  to  erupt,  the  case  may  then  be  one  for  extracting  the 
f  )ur  first  molars,  provided  it  be  necessary  to  extract  one  of  them,  or 
if  it  be  likely  that  one  or  more  of  them  will  be  lost   in  a  few  years. 


INDICATIONS  FOB   THE  OPERATION.  551 

If,  however,  the  bicuspids  are  not  in  good  position,  it  is  better  not  to 
extract  the  first  molars,  as  they  assist  in  keeping  the  jaws  the  proper 
distance  apart,  and  in  preventing  the  lower  anterior  teeth  from  biting 
against  the  upper  gum. 

Removal  of  Sound  Teeth  Preparatory  to  Inserting-  Artificial 
Dentures. — When  preparing  the  mouth  for  an  artificial  denture  the 
removal  of  sound  teeth  may  be  indicated  as  a  measure  of  expedi- 
ency in  relation  to  mechanical  and  hygienic  considerations.  For  ex- 
ample : 

(1)  Roots  which  a  plate  or  bridge  would  cover,  excepting  when  they 
assist  in  holding  the  device. 

(2)  Teeth  from  which  the  gums  have  receded  to  such  an  extent  as 
to  become  useless  or  unsightly. 

(3)  Teeth  that  are  being  extruded  from  their  alveoli  from  the  ab- 
sence of  occluding  teeth.  The  extraction  of  these  depends,  however, 
on  the  extent  of  "  elevation "  and  the  possibility  of  placing  occluding 
artificial  teeth  in  position. 

(4)  Where  there  is  but  one  tooth  remaining,  or  two  teeth  standing 
together,  or  in  certain  cases  when  several  isolated  teeth  remain  which 
cannot  be  made  to  contribute  to  the  mechanical  adaptation  of  an  arti- 
ficial denture,  extract  when  in  the  upper  jaw.  They  interfere  with  the 
fitting  of  an  upper  plate,  but  in  the  lower  jaw  they  may  be  useful  in 
retaining  the  plate. 

(5)  When  there  are  two  teeth,  one  on  each  side  of  the  upper  jaAV,  in 
good  position  and  desirable  shape  for  clasping,  do  not  extract  unless 
they  are  the  third  molars  or  the  oral  teeth. 

(6)  In  preparing  the  upper  jaw  when  two  canine  teeth  alone  remain, 
or  when  there  is  also  a  molar  or  bicuspid,  or  both,  and  it  is  decided  to 
extract  the  molars  and  bicuspids,  then  extract  the  two  canine  teeth  also. 
It  has  been  claimed  by  some  of  the  very  best  dental  practitioners,  whose 
opinions  must  be  respected,  that  by  keeping  these  teeth  the  expression 
of  the  face  is  less  likely  to  be  marred.  For  the  following  combined 
reasons,  however,  extraction  is  advised  : 

a.  It  is  very  difficult  to  obtain  a  correct  impression  of  the  mouth 
while  these  teeth  only  are  in  position. 

6.  It  is  nearly  impossible  to  perfectly  match,  grind,  and  arrange  the 
lateral  incisors  beside  single  canines. 

c.  The  adhesion  of  the  plate  to  the  mouth  is  interfered  with,  as  air 
and  food  work  in  between  the  plate  and  these  natural  teeth. 

d.  The  plate  is  very  much  weakened  by  being  cut  out  for  the  accom- 
modation of  these  teeth  at  what  might  be  termed  the  abutments  of  the 
arch.' 

In  the  loioer  jaiv  single  teeth  which  are  sound  are  usually  of  great 


552  EXTRACTION  OF  TEETH. 

iiiiportanct'.  Tlicy  slioiilil  not  l»c  i-<iii(ivc<l,  :is  llicy  nssist  in  retaining 
n  (IcMliirc  hy  means  of  clasits  or  otiicr  devices.  Kspecially  is  this  true 
in  jxTsons  advanced  in  yi-ars,  as  then  thi'  alveohir  process  is  jrenerally 
MUich  ahsorhed.  If  the  h»\ver  process  is  much  absorbed  oven  an  imper- 
fect tooth  will  do  good  service  of  this  character  for  a  time,  and  if  it  is 
the  first  plate  the  patient  has  W(trn  it  will  serve  a  ji:ood  purpose  by 
assisting  in  the  retention  of  the  plate  until  the  patient  has  become  ac- 
customed to  it,  after  which  the  tooth,  if  giving  trouble  or  il"  it  is  un- 
sightlv,  may  be  removed  and  an  artificial  one  placed  on   thi'  plate. 

Instruments  and  Accessories  for  Extracting. 

The  instruments  used  in  extracting  teeth  are  forceps  and  elevators 
of  various  shapes  and  sizes. 

Forceps. — The  forceps  should  be  made  of  steel  of  the  best  quality 
for  the  purpose  obtainable,  in  order  to  give  great  strength  and  stiffness, 
and  at  the  same  time  toughness,  so  that  they  will  not  break.  Forceps 
that  will  spring  or  bend  destroy  the  sensitivity  of  the  hand  using  them 
in  saich  a  way  as  to  prevent  the  ojicrator  from  discerning  in  what  di- 
rection the  resistance  to  extraction  is  being  made.  The  beaks  of  the 
forceps  as  a  general  principle  should  be  shaped  so  as  to  fit  and  adjust 
themselves  to  as  great  a  surface  of  the  various  teeth  or  roots  as  pos- 
sible so  that  they  may  take  a  firm  hold.  They  should  be  at  such  an 
angle  in  relation  to  the  handles  as  will  permit  them  to  be  easily  and 
readily  ])laced  in  the  proper  position  without  obscuring  the  view  of  the 
tooth  to  be  extracted.  The  inner  surface  of  each  beak  should  be  concave 
in  a  transverse  section  and  without  serrations,  as  these  are  of  no  assist- 
ance, but  tend  to  weaken  the  beaks  and  are  difficult  to  clean.  The  edges 
of  the  concave  portion  shotdd  l)e  sharp  enough  to  cut  through  the  alveolar 
process  if  necessary.  The  [mints  of  the  beaks  should  be  sharp  and 
tapering  so  they  can  be  forced  into  position.  The  handles  should  be  of 
a  shape  to  allow  a  firm  gras]),  and  as  the  hands  of  different  oj)erators 
vary  in  shape  and  size  it  will  be  evident  that  the  same  size  of  forceps 
handles  will  not  be  perfectly  satisfactory  to  all.  The  curvature  of  the 
handles  should  vary  according  to  the  general  or  special  use  of  the  for- 
ceps. The  curved  ends,  as  seen  in  Fig.  473,  are  of  little  use,  and  should 
be  done  away  with  in  all  forceps  excepting  perhaps  those  made  especially 
for  the  upper  and  lower  molars. 

The  joints  of  extracting  instruments  should  be  so  made  that  the 
handles  can  be  separated  by  some  simple  mechanism  to  permit  of 
thorough  and  easy  cleansing.  Figs.  473  and  474  represent  an  instru- 
ment of  this    character.     There   are  others  of   the    same    nature,  but 


INSTBU3IENTS  AND  ACCESSORIES  FOR  EXTRACTING. 


553 


Fig.  47? 


this  being  the  most  simple  and 
the  strongest  should  be  gen- 
erally adopted  nnless  a  similar 
device  can  be  adapted  to  the 
"  knuckle-jointed  "  instrument. 
(Fig.  475.) 

There  should  be  no  sharp 
angles  or  crevices,  and  if  the 
ordinary  forceps  be  used,  that 
portion  around  the  joint  in  a 
transverse  section  should  be  oval. 
Forceps  are  often  made  with 
octagonal  joints,  but  these  should 
be  condemned,  as  they  may 
not  only  hurt  the  lips  of  the 
patient,  but  in  case  of  a  slip, 
which  may  happen  with  the  best 
operators,  they  are  more  liable  to 
cause  injury  by  striking  the  other 
teeth ;  moreover  they  are  very 
clumsy  and  require  more  room. 

Fig.  474. 


Antiseptic  universal  lower  molar  forceps.  Joint  of  an  antiseptic  lower  molar  forceps 


EXTRACTION  OF  TEETH. 


Unless  tlic  antiseptic  joint 
(Figs.  473  and  474)  is  nsed  the 
nnion  of  the  joints  is  nsnally 
made  upon  one  of"  two  principles: 
first,  by  one  half  passin<i-  into  a 
mortise  in  the  othei-  and  held  in 
the  center  by  a  pinion  Fig.  476). 
The  second  is  known  as  a 
knnckle-joint  (Fig.  475)  made 
by  each  portion  being  let  half 
way  into  the  other  and  held  to- 
gether by  a  screw.  This  is  a 
neater  joint  and  does  away  with 
many  of  the  objectionable  fea- 
tures noted  in  other  forms  of 
forceps  joint. 

All  handles  should  be  ser- 
rated as  shown  in  the  illustra- 
tions, and  the  instruments  if 
properly  eared  for  need  not  be 
nickel-plated.  The  munber  of 
forceps  in  a  [)raetical  set  will 
vary  with  the  requirements  of 
every  individual  who  extracts 
teeth,  therefore  oidy  the  general 
principles  which  should  govern 
the  selection  of  a  set  of  instru- 
ments will  be  here  given  ;  at  the 
same  time  the  uselessness  of  a 
very  large  selection  is  here  eni- 
])hasized.  As  an  illustration  of 
the  range  of  tooth  extractions 
V^  which  may  be  performed  with  a 
%  limited  number  of  instruments 
the  forceps  represented  by  Figs. 
476  and  477,  showing  the  exact 
size,  will  serve  as  examples. 
They  are  smaller  than  the  ones 
generally  nsed,  especially  in 
America. 

The  instrument  shown  in  Fig. 
476  may  be  used  almost  universally  for  the  upper  teeth. 

Fig.  477  is  a  forceps  of  the  same  general  character  as  that  in  Fig. 


Knuckle-joint  root  forceps. 


INSTEU3IENTS  AND  ACCESSORIES  FOR  EXTRACTING.         555 
476,  only  the  beaks  are  at  a  different  angle  with  the  handles.     This  pair 

Fig.  476.  Fig.  477. 


W0l 


Universal  upper  incisor  and  root  forceps. 


Tlniversal  lower  incisor  and  root  forceps. 


may  be  used  similarly  for  the  lower  teeth.     These  forceps  are  useful  in 
all  cases,  excej^t  in  the  full  arch,  M^hen  either  a  first  or  second  molar  is 


556 


EXTRACTIOy  OF  TEETH. 
Fig.  478.  Fig.  479. 


\ 


For  the  ten  upper  anterior  teeth. 


Root,  apper  iiunt.    Straight. 


lysTRr^rEXTS  axb  accessories  foe  extracting. 


oo< 


Fis.  480. 


to  be  extracted.      If  the  teeth  are  large,  the  jaw  strong,  and  the  line  of 

grinding  surfaces  concave,  it  is 
better  to  use  the  special  lower 
molar  forceps  as  sh<iwn  in  Fig-s. 
473  and  4<S6. 

Fig.  478  and  Fig.  479  rep- 
resent very  useful  forceps  for 
extracting  the  ten  upper  an- 
terior teeth.  Fig.  479  has 
longer  beaks  and  its  points  are 
finer.  In  skillful  hands  where 
too  great  a  force  will  not  be 
brought  to  bear  on  the  points 
they  are  the  better  forceps. 
Under  nitrous  oxid  and  where 
many  teeth  are  to  be  extracted, 
thus  requiring  rapid  work,  the 
instrument  shown  in  Fig.  478 
is  preferable. 

Figs.  480  and  481,  right  and 
left,  represent  forceps  specially 
used  for  extracting  the  first  and 
second  upper  molars  on  either 
side.  The  outer  beak  is  made 
pointed  for  the  purpose  of  pass- 
ing in  between  the  buccal  r(X)ts, 
the  inner  beak  is  concave  in 
order  to  grasp  the  palatal  root. 
Figs.  483  and  484  show  bayonet- 
shaped  forceps,  that  illustrated 
by  Fig.  483  being  especially 
made  for  extracting  the  upper 
third  molars,  Fig.  484  being 
used  for  upper  roots.  The  ends 
of  the  handles  of  all  forceps 
which  are  forced  in  by  the  palm 
of  the  hand  should  have  a  broad 
surface  as  shown  in  Fig.  484. 
These  forceps  are  popular  with 
many  operators.  The  writer 
considers  them  clumsy,  as  thev 
obscure  the  proper  view  of  the 
tooth  and  its  associated  parts. 


Fdght  upper  molar. 


508  EXTRACTION  OF  TEETH. 

Fm.  481.  Fio.  482. 


Left  upper  molar 


Hawk-beaked  forceps. 


INSTRUMENTS  AND  ACCESSORIES  FOR   EXTRACTING.  559 

Fig.  483.  Fig.  484. 


i^S 


r\^ 


'X/ 


Universal  upper  third  molar. 


Dorr's  upper  root  forceps. 


560 


EXTRACTION  OF  TEETH. 


Fuj.  485. 


Fkj.  ISO. 


Tniversal  lower  canines  and  bicuspids. 


Universal  lower  molars,  designed  by  Dr. 
Chapln  A.  Harris. 


INSTBUMENTS  AND  ACCESSORIES  FOR  EXTRACTING.         561 
Fig.  487. 


Fig.  489. 


Root,  lower.    Half  curved. 
36 


Elevator. 


Eight  and  left  scalers 
used  for  extracting 
roots. 


562  EXTRAVTIOS   OF   TKKTII. 

Ponrps  for  Kvinicfiii;/  Loircr  Ticlh. —  I  iistc:ul  of  the  l)eak8  of  the 
forceps  being  nearly  on  a  line  with  the  handles  as  in  those  for  the  upper 
jaw,  they  are  bent  at  nearly  a  right  angle.  For  the  ineisors  of  the  lower 
jaw  there  are  no  better  forceps  than  those  shown  in  Fig.  477.  This 
instrument  is  very  useful  in  extracting  the  lower  third  molar  when  fix- 
ation of  the  jaw  from  diffuse  cellulitis  in  the  region  of  the  temporo- 
maxillarv  articulation  renders  it  difficult  to  open  the  mouth  suHieiently 
for  inserting  a  larger  instrument.  In  such  cases  the  forceps  should  be 
carried  bacTcward  in  the  vestibule  of  the  mouth  with  the  inner  beak 
passing  between  the  upper  and  lower  teeth  ;  when  the  beaks  reach  the 
third  molar  the  inner  beak  can  usually  be  forced  over  the  inner  surface 
of  the  tooth  and  into  position,  after  which  the  tooth  can  be  grasped 
and  extracted.  The  forceps  represented  in  Fig:  476  can  also  be  used 
to  advantage  for  these  teeth,  the  operator  standing  behind  and  working 
over  the  head  of  the  patient,  as  shown  in  Fig.  539. 

Fig.  482  exhibits  a  hawk-beaked  forcei)s  for  extracting  the  anterior 
lower  teeth.  It  is  very  popular  with  some  operators,  especially  those  in 
Europe.     The  writer  does  not  recommend  it. 

Fif.  485  also  exhibits  a  special  instrument.  It  is  made  for  extract- 
inu-  the  lower  canine  and  bicus])id  teeth  of  either  side.  Fig.  486  is  a 
special  instrument  used  for  the  lower  molars  of  either  side.  The  beaks 
are  pointed,  with  a  concavity  on  each  side  of  the  point  to  allow  it  to  pass 
in  between  the  roots.     The  two  concave  portions  fit  against  each  root. 

Fig.  487  represents  a  universal  lower  root  forceps. 

Elkvators  or  Root  Extractors. — There  are  many  kinds  of  ele- 
vators used  in  extracting  roots.  Some  are  also  occasionally  used  in  the 
extraction  of  teeth  (usually  the  third  molar). 

Fig.  488  shows  one  of  the  most  useful  forms  of  this  instrument.  It 
is  especially  useful  in  extracting  third  molars  when  the  teeth  in  front 
of  them  are  in  position.  Also  for  the  removal  of  impacted  teeth  by 
passing  in  between  the  impacted  tooth  and  an  adjoining  tooth,  or  between 
the  tooth  and  the  bone,  the  concave  portion  being  placed  against  the  tooth 
to  be  removed.  It  is  also  useful  as  a  gonge  at  times  in  removing  bone 
that  is  overlying  an  impacted  tooth. 

Fig.  489  represents  two  elevators;  they  are  similar  to  right  and  left 
scalers,  being  made  somewhat  heavier;  they  are  extremely  useful  in  extract- 
ing roots.  They  are  so  unlike  an  extracting  instrument  that  patients  do 
not  dread  the  appearance  of  them  as  they  do  that  of  forceps.  By  care- 
fully inserting  the  blade  with  the  point  toward  the  root  to  be  removed, 
between  it  and  the  adjoining  root  or  tooth,  and  giving  a  slight  rotary 
motion,  the  point  will  force  the  root  from  its  socket  with  but  little  pain. 

Figs.  530  and  531  illustrate  two  other  forms  of  elevator,  with  their 
mode  of  application  in  the  removal  of  roots. 

Lancets. — Figs.  490  and  491   represent  various  forms  of  lancets, 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING. 


563 


the  more  useful  of  which  are   Nos.  1   and   5,  which  are  all  that  are 

required  for  lancing  in  extracting  or  for  relief  of  retarded  eruption  of 

deciduous  or  other  teeth.     They  are  also  useful  in  general  surgery  of  the 

mouth.     The  handles  should  be  made  of  metal  instead 

Fig.  490.  ^f  wood,  in  order  that  they  may  be  thoroughly  sterilized. 


W 


Fig.  491. 


if  asked  to 
nitrous  oxid 


Lancets  with  ebony  handles  and  with  solid  steel  handles. 

Scissors. — A  good  pair  of  curved  scissors,  as  shown 
in  Fig.  492,  should  be  at  hand  in  case  a  portion  of 
gum  tissue  is  found  to  be  attached  to  the  root.  If  the 
scissors  were  slightly  more  curved  they  would  be  even 
better  adapted  for  this  purpose. 

In  connection  with  the  instruments  already  men- 
tioned, there  should  be  a  mouth  mirror  (Fig-  493) 
and  a  few  excavators  and  probes  for  general  exami- 
nation of  the  teeth,  especially  for  examining  the  position 
and  character  of  a  root  or  impacted  tooth  which  it  is 
purposed  to  extract. 

Mouth  Props. — When  an  anesthetic  is  to  be  given 
it  is  advisable  to  use  some  kind  of  a  mouth  prop,  in 
order  to  keep  the  mouth  well  open.  Corks  1|  inches  in 
length,  1^  inches  at  the  base,  and  |  of  an  inch  at  the 
small 'end  are  very  useful  for  this  purpose  when  placed 
between  the  jaws,  with  the  small  end  in  the  mouth.  Some 
operators  do  not  use  them,  as  they  may  interfere  with  the 
giving  of  the  anesthetic  by  impeding  respiration  upon 
beginning  the  administration.  The  majority  of  patients, 
hold  the  mouth  open  while  taking  the  anesthetic,  especially 
and  oxygen,  will  keep  it  open  during  the  anesthetic  stage. 


564 


EXTRACTION  OF  TEETH. 


Fi(i.  492. 


Fig.  494  illustrates  oxccilcnt  i)r.)|)s  dcvixd  by  Dr.  Frederic  Hewitt, 
of  London,  P^ngland. 

The  Mechanical  Mouth-opener  (Fig.  495). — This  instrument 
is  made  in  various  shapes  and  sizes.  It  is  inserted  between  the  jaws 
when  the  props  are  to  be  removed  or  in  eases  of  trismus,  and  may  also 
be  used  to  separate  the  jaws  and  retain  them  so  in  cases  of  emergency 
or  during  certain  operations  within  the  oral  cavity. 

All  <lcnti«;ts,  and  especially  those 
who  extract  teeth,  should  have  at 
least  one  pair  of  I'HAKynoeal  for- 
ceps (Fig.  496).  It  is  possible  that 
they  may  never  be  used,  but  on  the 
other  hand  an  accident  may  occur 
such  as  a  fragment  or  tooth  slip- 
ping into  the  pharynx,  where  if  the 
finger  cannot  reach  it  this  instru- 
ment will  be  absolutely  necessary. 
Surgical  Anatomy. — To  extract 
teeth  successfully  it  is  first  neces- 
sary to  be  perfectly  familiar  w'ith 
the  general  shapes  of  the   different 

Fig.  493. 


Curved  scissors. 


Mouth  mirror. 


teeth  and  their  position  in  relation  to  the  jaw  and  to  their  associates,  in 
order  that  the  operator  may  intelligently  apjjly  the  force  in  the  line  of 
the  least  resistance  required  for  their  removal.  This  knowledge  cannot 
be  obtained  from  books  ;  they  are  but  the  guides  to  it.  The  jaws  of  the 
dead  subject  must  be  dissected — both  the  cleaned  bones  and  those  with 
the  soft  tissues  left  upon  them.  "  Di.-section  "  means  that  not  only 
shall  the  superficial  relations  be  studied,  but  that  the  bones  shall  be  cut 


INSTRUMENTS  AND  ACCESSORIES  FOR   EXTRACTING. 


565 


in  various  directions,  both  with  the  saw  and  other  instruments,  until 

the  relations  of  the  teeth  of  the  upper  jaw  with  the  floor  of  the  nasal 

chamber  and  the  maxillary  sinus  are  fully  understood.     In  the  lower 

jaw  the  relations  of  the  teeth  with  the  inferior  dental  canal  and  the 

position  of  the  roots,  especially  those  of  the  third  molar,  must  also  be 

thoroughly  known. 

Fig.  494. 


^^ 


&  ^ 


Hewitt's  mouth  props  (half  size). 


The  alveolar  process  of  both  jaws  is  made  up  of  two  plates,  external 
and  internal,  consisting  of  dense  compact  bone  without  a  true  line  of  de- 


FiG.  495. 


Mechanical  mouth-opener  (half  size). 


marcation  between  the  process  and  maxilla  proper.     The  sockets  for  the 
roots  of  the  teeth  are  situated  in  the  interspaces  between  these  plates  and 


Fig.  496. 


Pharyngeal  forceps  (half  size). 


are  surrounded    by   a  very   thin   porous   plate  of  cortical  bone.      The 
remaining  space  is  filled  with  cancellated  tissue,  small  bony  channels,  con- 


566 


EXTRACTION  OF  TEETH. 


iK'ctivc  tissue,  nerves,  vessels,  ete.  As  this  process  belongs  io  the  teeth, 
is  developed  with  them,  and  is  lor  the  pnr[)()se  of  holding  them  in  j)osi- 
tion,  it  disa})pears  to  a  greater  or  less  extent  when  the  teeth  are  lost.  'I'he 
res(ir])tion  of  this  process  does  not  take  place  alike  in  each  jaw.  In  the 
npj)er  jawthe  external  ])late  disappears  more  ra})idly  and  to  a  greater  de- 
gree than  the  inner  plate  ;  in  the  lower  jaw  the  resorption  of  the  two  plates 
is  about  e(|Ual  in  extent  and  rate.  The  iimer  plate  of  the  upj)er  jaw  is 
partially  suj)p()rted  by  the  external  j)late  of  the  palatal  ])ro('ess,  in  fact 
one  nu'rges  into  the  other.  The  outer  alveolar  ])late  of  the  npj)er  jaw 
bi'ing  resorbed  to  a  greater  extent  than  the  inner  one  is  of  advantage 
to  the  dentist  in  fitting  teeth  to  the  gums  ;  consecjuently,  in  extrac- 
tion that  fact  should  be  remend)ered  and  injury  to  the  internal  ])late 
avoided.  At  the  same  time  it  does  no  harm  to  remove  a  small  ])or- 
tion  of  the  outer  ])late,  though  loss  of  the  gum  tissue  shouKl  be 
avoided  if  possible.     In  the  lower  jaw  it  is  not  so  important  to  avoid 


Fig.  497. 


•   Alveoli  of  permanent  teeth— upper  jaw. 

removing  slight  ])ortions  of  the  inner  plate,  as  resorption  takes  place 
about  e(jually  in  the  two  plates. 

These  plates  may  be  resorl)ed  in  such  a  manner  that  a  slight  ridge 
is  left  between  the  places  whieli  they  occnj)ied.  This  resorption  of 
both  plates  of  the  alveolar  process  of  the  lower  jaw  makes  it  more  diffi- 
cult to  fit  single  plain  teeth  in  the  lower  than  in  the  upper  jaWe 


SURGICAL  ANATOMY 

Fig.  498. 


567 


Alveoli  ijf  puniiiiiR'nt  teeth— lower  jaw. 
Fio.  499. 


r  1'  Ti  \ 


Typical  upper  and  lower  jaw. 


5G8 


EX TR ACTIOS   OF  TEETH. 


Fig.  4117  sliows  tlu'  iilvciili  tif  tlic  ii])])cr  (Iciiliirc,  l-'iir.  JOS  that  of  the 
lower. 

Fig.  499  illu>trati's  a  tyjtical  ii|>]»cr  aiitl  ii.wcr  jaw,  tlio  cxtornal  siir- 


Fiu.  500. 


Showing  the  occlusal  surfaces  of  the  upper  teeth.    (From  same  skull  ns  Fig.  499.) 

faces  of  the  crowns  of  the  teeth,  also  a  normal  occlusion.  Figs.  500 
and  501  illustrate  the  occluding  surfaces  of  the  teeth  and  their  relations 
with  each  other.     They  are  made  from  the  same  skull  as  Fig.  499. 

Fig.  501. 


^,^ 


V. 


Showing  occlusal  surfaces  of  the  lower  teeth.    \l''rom  same  skull  is  Fig.  J99.) 

Fig.  502  is  from  a  photograph  taken   from  tlie  right  side  of  a  skull. 
It    gives    a    good   repre.'^cntatinn    of  a   fairly  normal    occlusion    of  the 


SURGICAL   AXATOMY. 

YiG.  502. 


569 


Showing  the  buccal  surfaces  of  the  crowns  and  roots  in  position. 
Fig.  503. 


670 


FXrEACTfOy   OF   TEETH. 


t«'ctli,  tlioir  shup(>,  n)()ts,  aiul  their  nlation   with   tlic  caiKMlhitcd  tissue 
aiul  the  inltTior  ikiital  t-aual  or  frihrHonn  tube  of  the  Inw.r  luaxilhi. 


Hintus 
semilumiiiari. 


Fl...  004. 

Middle  etbmuidal 
cells. 


I Crvstiilliiif  lenses. 


riK'inate  proces-s. 
LMiildlc  turbinated 
iMine. 
Middle  meatus. 
.Maxillary  .sinus, 
nferior  meatus, 
iiferiur  turbinated  bone 


■Vestihule  of  mouth. 
First  molar. 

Distal  root  first  molar. 
Inferior  dental  nerve. 


An  anterior  view  of  a  vertical  transverse  .section  of  the  head,  showing  the  relations  of  the  jaws  and 
the  U-shaped  bone  of  the  mandible. 

In  tlie  upper  jaw  tlie  bone  is  thin  over  the  position  of  the  molar  teeth, 
and  tlieir  roots  are  comparatively  straiirht  ;  none  of  these  should  be 
difficult  to  extract.  The  buccal  roots  of  the  first  molar  are  somewhat 
divergent  from  each  other.  The  same  roots  of  the  second  molar  spread 
only  slightly  as  they  leave  the  crown  and  close  in  at  the  points.  1  he 
roots  of  the  third  molar  are  together  and  slightly  curved  backward.  In 
the  lower  jaw  the  roots  are  cotnparatively  straight.  Those  of  the  first 
molar  are  spread  only  a  little  apart,  this  being  the  usual  condition. 
The  roots  of  the  .second  molar  are  almost  straight  and  are  nearly  parallel 
with  each  other.  The  anterior  root  of  the  third  molar  curves  .slightly 
backward   until   it  joins  the  posterior  root. 


SURGICAL  JJJ^ATOMY. 


571 


Fig.  503  is  taken  from  the  left  side  of  the  same  jaw  as  Fig.  502.  In 
Fio^.  502  the  roots  have  been  exposed  down  to  their  apices ;  in  Fig.  503 
only  the  external  or  cortical  plate  has  been  removed.     These  two  illus- 


Oms 


1st  J/  Ut  M 

Posterior  view  of  vertical  transverse  seetiuu  of  the  head  froiu  the  .same  skull  as  Fig.  504,  showing 
the  ostium  maxillare,  which  is  indicated  on  each  side  by  a  cord  passing  through  it:  07>i,  Ostium 
maxillare  ;  1st  M,  first  molar. 

trations  give  a  correct  idea  of  the  relations  of  the  teeth  to  the  internal 
structures  of  the  jaw. 

Figs.  504  and  505  are  good  illustrations  of  the  relations  of  the  roots 
with  the  floor  of  the  maxillary  sinus  usually  found  in  the  white  race. 

Fi(,    )0() 


Ar  1st  M,  Anterior  root  of  first  molar;  E  2d  Bi,  root  of  second  bicuspid;  Idn,  inferior  dental 
nerve ;   Up,  U-shaped  or  cortical  section  of  lower  jaw. 

In  the  negro  there  is  usually  a  considerable  thickness  between  the 
teeth  and  the  floor  of  the  sinus.  It  will  be  noticed  that  the  roots  of 
the  molars  pass  up  on  both  sides  of  the  sinus,  and  because  of  this  fact 


572 


EXTRACTION  OF  TEETH. 


it  is  noocpstirv  in  ('xtnic(in(r  Icotli  rrom  m  jiiw  of  lliis  cliarMctcr  to  use 
tli(>  irrcMlcsl  cMiitinn,  otherwise  a  portion  ol"  llie  floor  oCtliat  cavity  iniL""!!! 
also  he  removed.      Or  if"  a  tootli  l)e  Itrokcii  and  inneli  Uj)\vard  force  nsed 


Fig.  507. 

Contral      I.atoral 
iHisiir.      iiu-is(ir.        Ciuiine. 


First  bicuspid. 
Second  bicuspid. 


Second  molar. 


First  molar. 


It'ri^'siO^. 


Second  bicuspid. 
First  bicuspid. 


Horizontal  section  of  the  tapper  and  lower  jaw.s  cut  a  little  beyond  the  tree  margin  of  the  alveolar 
process,  showing  tht  forms  and  position  of  the  roots  of  the  various  teeth. 

in  endeavoring  to  take  hold  of  the  root,  the  latter  could  easily  1)C  forced 
into  the  sinus.  The  lower  portion  of  Fig.  504  gives  a  general  idea 
of  a  transverse  section  of  the  lower  jaw  made  posterior  to  the  mental 
foramen.  Es})ecial  attention  is  drawn  to  the  U-shaped  formation  of 
the  cortical  portion  of  the  lower  jaw  which  terminates  in  the  two  plates 
of  the  alveolar  process^  and  between  which  the  roots  are  imbedded  in 


SURGICAL  ANATOMY. 


b1{ 


the  cancellated  tissue.  It  also  shows  how  the  roots  extend  tow^ard  the 
inferior  dental  nerve.  There  is  no  line  of  demarcation  between  the 
alveolar  process  and  the  body  of  the  bone. 

Fig.  506  shows  the  relation,  length,  and  position  of  the  second  bicus- 
pid, showing  that  its  root  is  sonaetimes  placed  to  the  inner  side  of  the 
anterior  root  of  the  first  molar.  The  roots  of  these  bicuspids  are  flat,  as 
will  be  seen  by  looking  at  Fig.  526.  On  taking  into  consideration  their 
length,  position,  and  thinness  it  will  be  readily  seen  w^hy  it  is  so  often 
difficult  to  extract  them  without  breaking. 

Fig.  507  is  taken  from  horizontal  sections  of  the  lower  and  upper 
jaws,  showing  the  transverse  sections  of  the  roots  of  the  teeth.  The 
section  is  made  a  little  above  the  margin  of  the  alveolar  process  of  the 
upper  jaw  and  a  little  below  in  the  lower.  The  illustration  shows  the 
shape  and  position  of  the  various  roots,  with  their  relations  to  the  pro- 
cess and  to  each  other.     Particular  attention  should  be  given  to  the  fact 


Fig.  508 


R  2d  M. 


R  1st  M- 


R2dBi 


R  1st  Bi 


Horizontal  section  of  the  lower  jaw  cut  in  the  region  of  the  points  of  the  roots  of  the  teeth : 
Dn,  Dental  nerve  ;  It  3d  M,  roots  of  third  molar ;  R  2d  31,  roots  of  second  molar ;  R  1st  M,  distal 
root  of  first  molar;  R  2d  Bi,  root  of  second  bicuspid;  R  1st  Bi,  root  of  first  bicuspid;  Re, 
root  of  canine ;  Rli,  root  of  right  lateral  incisor. 

that  the  roots  and  process  are  in  such  close  relation  as  to  make  it  im- 
possible to  force  the  beak  of  a  forceps  between  them  without  breaking 
one  or  both  plates  of  the  process.     The  lines  leading  from  the  roots 


74 


EXTRACTION  OF  TEETH. 


sliow  tlio  proper  direction  for  aj>])lying  what  is  known  in  t'xtractin<r 
as  the  "  out-and-in   motion." 

Fit;.  Ot).S  represents  a  horizontal  section  made  thronjih  tiie  lower  jaw 
near  the  ends  of  the  roots,  and  from  the  same  hone  as  that  shown  in  the 
lower  half  of  Fig.  5(>7.  The  eaneellated  portion  with  the  soft  tissne 
tillini;  the  spaces  can  be  plainly  seen.  The  nerve  j)assinjj;  into  its  tnbe, 
the  ends  of  the  roots  of  the  second  and  third  molars,  the  tip  of  on(>  of 
the  roots  of  the  first  molar,  and  the  roots  of  the  first  and  second  hicus- 
])ids  are  all  plainly  shown.  A  little  of  the  lateral  incisor  can  l)e  noticed, 
hnt  the  centrals  do  not  reach  so  far  down. 

Figs.  509  and  510  are  taken  from  a  sagittal  section  of  the  npper 
jaw,  external  to  the  infraorbital  foramen,  and  through  the  roots  of  the 


Fig.  509. 


Fig.  510. 


Amrr(i-|i()>tt.'ric>r  (Hvisioii  el'  tbf  maxilla,  showing 
opening  of  a  dental  abscess  within  the  antrum 
and  an  infraorbital  sinus :  Jfs,  Infraorbital 
sinus ;  If,  infraorbital  foramen ;  Pic,  piece  of 
paper  {)assing  through  infraorbital  canal;  Ms, 
maxillary  sinus ;  Ac,  apical  abscess. 


Om,  Opening  into  ninlarbone; 
JJs,  infraorbital  siuus. 


molar  teeth.  This  illustration  shows  how  the  roots  often  extend  above 
the  lower  portions  of  the  floor  of  the  sinus,  an  abscess  from  the  palatal 
root  of  the  first  molar  having  discharged  into  the  floor  of  the  sinus 
at  the  point  ,1a. 

It  has  been  demonstrated  both  anatomically  and  clinicaJly  that  in- 
fectious matter  from  a  suppurating  tooth  may  eventually  give  rise  to  an 
inflammation  of  the  meninges  of  the  brain.  Should  pus  from  a  dento- 
alveolar  abscess  discharge  into  the  maxillary  sinus  it  may  pass  out  into 
the  hiatus  semilunaris  and  ascend  into  the  frontal  sinus  or  in  tlie  vicin- 
ity of  the  cribriform  plate  of  the  ethmoid  through  the  infundibulura  when 


SURGICAL  ANATOMY. 


575 


Fig.  511. 


Longitudinal  division  of  a  mandible,  exposing  the  cancellated  tissue  in  the  body  of  the  jaw  and 
between  the  sockets  of  the  teeth. 

Fig.  512. 


4 


D 


%^ 


■j':<' 


'.\>t' 


F  G  H  I  J 

Sections  made  at  different  points  from  a  mandible  which  was  not  quite  normal  in  its  density. 


576 


EXTRACTION  OF  TEETH. 


tlie  passage  tlinmixli  the  liintus  into  the  middle  incatiis  is  small  or  con- 
stricted, as  it  usually  is  wlicn  inflamed,  or  the  pus  may  j)ass  directly 
tlu'ough  the  inf'undibnhim.  Recent  research  has  shown  that  the  frontal 
sinus,  the  crihritorm  plate  of  the  ethmoid,  and  the  meninges  of  tlie  brain 
are  in  close  relation  at  the  anterior  portion  of  the  cribriform  plate,  a  dis- 
eased condition  at  -vvhich  point  is  liable  to  involve  all  three  structures. 


Fig.  513. 


Fig.  511  is  from  a  longitudinal  section  of  the  lower  jaw,  and  gives  a 
good  idea  of  the  cancellated  tissue,  the  relations  of  the  .sockets  of  tiie 
teeth  to  one  another,  and  the  position  of  the  inferior  dental  canal. 


Fig.  514. 


An  uiicoinnioii  impiicted  lower  third  mi)lar. 


Fig.  512  is  taken  from  several  transverse  sections  of' a  lower  jaw. 
The  bone  is  not  quite  normal,  as  several  teeth  were  extracted  before 
death,  the  loss  having  caused  changes  in  the  character  of  the  bone. 
Some  of  the  sections  show  but  one  canal,  while  in  others  there  are  many. 


SURGICAL  ANATOMY. 


577 


requiring  close  observation  to  determine  in  which  the  inferior  dental 
nerve  and  vessel  has  passed. 


Fig.  515. 


A  view  of  ail  impacted  lower  third  molar. 


Fig.  513  is  taken  from  the  inner  side  of  tlie  right  half  of  a  lower 
jaw.  The  second  molar  has  been  broken  off,  the  roots  still  remaining 
in  position.     The  points  of  the  roots  of  the  third  molar  pass  out  through 


Fig.  516. 


A  second  view  of  an  impacted  lower  third  molar,  as  shown  in  Fig.  515.  Part  of  the  distal  root  of 
the  second  molar  has  been  resorbed,  exposing  the  root  canal,  more  than  likely  causing  the 
devitalization  of  the  tooth,  and  thus  producing  neuralgia. 

the  inner  wall  a  considerable  distance  below  the  mylo-hyoid  ridge.  A 
portion  of  the  ridge  has  been  cut  away,  exposing  the  remainder  of  the 
internal  surface  of  the  roots.  This  will  be  further  alluded  to  when  ex- 
traction of  the  lower  third  molar  is  considered. 

37 


678 


EXTRACTION  OF  TEETH. 


Figs.  515  and  516  are  from  tlie  outer  side  of  the  rifjht  half  of  a  lower 
jaw,  Fig.  515  showing  an  impacted   third   molar  lying  horizontally   in 


P^Kj.  517. 


liua-r  sidu  of  luft  half  of  lower  jaw,  showing  an  impauted  third  molar. 

the  jaw.     Fig.  516  is  of  the  same  jaw  with  the  tooth  removed  from  its 
bed,  showing  the  inner  surface.     The  second  molar  is  a  pidpless  tooth 

Fig.  518. 


n.'.   i!7,  with  the  impacted  molar  removed  from  its  Vied.) 


the  distal  root  of  which  shows  where  the  impacted  t<joth  has  pressed 
against  it,  causing  the  absorption  of  a  portion  of  the  root  and  exj)osing 
the  pulp  canal  within,  proilucing  death  of  that  organ.     This  must  hav.e 


SURGICAL  ANATOMY. 


579 


caused  neuralgia.  The  cancellated  tissue  of  this  bone,  it  will  be  noticed, 
is  not  like  that  shown  in  Fig.  503,  the  change  in  the  character  of  this 
tissue  being  the  result  of  irritation.     It  will  be  seen  that  the  roots  of  the 


Fig.  519. 


Right  half  of  lower  jaw,  showing  a  lower  third  molar  with  thickened  and  curved  roots. 

other  teeth  in  this  jaw  are  longer  than  usual,  the  canine  tooth  passing 
below  the  nerve  and  to  the  outer  side. 

Figs.  517  and  518  represent  the  inner  side  of  the  left  half  of  a  lower 
jaw.     It  shows  an  impacted  third  molar  pointing  slightly  downward. 

Fig.  520. 


(f^  „. 


Left  half  of  lower  jaw,  showing  a  third  molar  lying  horizontally  and  the  bone  much  more  dense 

than  normal. 

The  distal  root  of  the  second  molar  is  slightly  absorbed.  On  uncover- 
ing the  tooth  and  taking  it  from  its  bed,  it  was  found  to  be  incased  in  a 
thin  shell  of  bone  as  though  the  dental  sac  had  ossified  separately  around 
this  tooth ;  this  thin  incasement  of  bone  may,  however,  have  been  an 


580 


EXTRACTION  OF  TEETH. 


inflammatory  product.      Flie  inner  portion  of  this  shell  can  be  seen  in 
position.     The  nerve  and  its  accompanying  tissue  passes  into  the  infe- 


Fici.  h'l\. 


Showing  two  ordinary  impacted  lower  third  molars. 

rior  dental  foramen  immediately  against  the  shell,  and  has  the  appear- 
ance of  being  flattened  out.  It  divides  and  sends  a  branch  around  the 
internal  half  of  the  shell. 

Fk;.  .VJ2. 


X-ray  iiicturt-  made  from  the  left  siile  of  Fig.  ol\. 


Figs.  519  and  520  are  taken  from  the  right  and  left  halves  of  the 
lower  jaw.      Fig.  519  shows  the  internal  surface  of  the  right  half; 


SURGICAL   ANATOMY. 
Fig.  523. 


581 


Side  view  of  two  ordinary  impacted  lower  third  molars,  the  bone  having  been  removed  in  order 

to  expose  tlie  roots. 


Fig.  524. 


Showing  an  inverted  lower  third  molar  erupting  into  the  submaxillary  fossa  (Dr.  Whitney). 


o82 


EXTRACTION  OF  TEETH.. 


Fig.  520,  the  oxtcnuil  siirihcc  of  the  same  In  Fig.  51  i»  the  roots 
of  the  tliird  mohir  furvc  haekward,  are  joined  together,  and  are  so 
enhirged  by  an  abnormal  deposit  of  cemcntnm  eansed  bv  eontinued 
hyperemia  due  to  the  prolonged  irritation  that  the  form  of  each  root 


Fig.  525. 


Deciduous  teeth— k'tt  side  (Hurchard) 


is  lo.'Jt ;  the  bone  also  is  much  thickened.  Fig.  520  shows  an  impacted 
tooth  pressing  directly  against  the  one  in  front  of  it,  the  roots  of  which 
have  become  much  enlarged  by  the  deposit  of  cementum.  The  sur- 
rounding bone  is  also  thickened  and  much  more  compact  than  the  nor- 


FiG.  526. 


Permanent  teeth— right  side  (Burchard). 

mal  bone.  The  character  of  the  cancellated  tissue  of  the  lower  jaw  is 
lost  by  the  deposit  of  bone  caused  by  continued  irritation  of  that  tissue. 
Figs.  525  and  526  show  the  normal  forms  of  the  teeth,  and  Fig.  527 
is  taken  from  a  group  of  abnormal  teeth.  If  only  normal  conditions 
of   the  teeth  had  to  be  considered,  as  shown   in    Figs.   525  and  526, 


SURGICAL  ANATOMY. 


583 


extraction  would  be  a  very  simple  operation,  but  unfortunately  this  is 
seldom  the  case.  It  often  happens  that  even  when  the  teeth  them- 
selves are  normal  they  are  situated  in  abnormal  positions,  and  for  this 


Fig.  527. 


Abnormalities  in  teeth. 


reason  alone  their  extraction  becomes  necessary.  In  fact,  so  varied  and 
complicated  are  the  different  abnormalihes  presented,  that  it  would  be 
impossible  to  describe  them  all.  The  diagnosis  of  unerupted  teeth  occu- 
pying abnormal  positions  has  been  greatly  facilitated  by  special  applica- 


584 


EXTRACTION  OF  TEETH. 


tions  of  tlio  skiajjrapllic  iiu'tlxtd.  Its  fiirtlior  use  in  this  comioctioii  is 
l)ut  a  ((Uestion  of  time  and  (lov('l()])niont.  A  careful  study  of  the  eoin- 
plications  most  frequently  oecurrint!;  will,  however,  i>ive  j^ood  ])re])aration 
for  meeting  the  emergencies. 

Figs.  513  to  524  and  528  show  abnormal  ])ositions  of  various  tt'oth. 
It  will  he  readily  seen  that  no  set  of  rules  could  he  made  to  govern  the 
extraction  of  these  teeth  ;  therefore  only  the  general  j>rineij)les  govern- 
ing extraction  can  be  here  set  forth. 

General  Principles  in  Extracting  Teeth. 

These  principles  may  be  classified  under  tlic  following  heads: 

(1)  Management  and  Position  of  Patients. 

(2)  Selection  of   Instruments. 

(3)  Technit[ue  of  the  Operation. 

Management  of  Patients. — The  first  important  step  toward  a  suc- 
cessful operation  in  dentistry  is  to  gain  the  confidence  of  the  patient, 
who  must  be  brought  to  rely  entirely  on  the  judgment  and  skill  of  the 


Fio.  528. 


Abiiormiil  jaw  showing  impacled  canines. 

operator.  If  the  operator  feels  entire  confidence  in  his  own  ability  to 
successfully  carry  out  an  operation  he  can,  by  his  manner  of  approaching 
the  patient,  impart  a  feeling  of  almo.^it  absolute  trust  in  his  skill.  This 
feeling  of  confidence  in  himself  should  be  cultivated,  as  it  is  evident 
that  a  slight  nervousness  on  his  part,  even  though  he  be  most  skillful, 
will  tend  to  alarm  the  {latient  to  such  an  extent  as  may  cause  great 
interference  with   tiie  operation. 

Position   of    tiik    Patient. — The   princij)al   object   to   secure   in 
placing  the  patient  is  to  obtain  a  good  view  of  the  affected  tooth  and 


GENERAL  PRINCIPLES.  585 

contiguous  parts ;  after  which  the  position  should  be  made  as  comfort- 
able as  possible  both  for  the  patient  and  operator,  taking  care  that  the 
territory  of  operation  can  be  reached  with  but  little  strain  or  eifort. 

The  position  both  of  patient  and  operator  varies  slightly  for  the 
extraction  of  each  tooth.  The  main  points  to  be  observed  are  to  have 
the  particular  tooth  to  be  operated  upon  in  view,  and  the  head  of  the  pa- 
tient in  such  a  position  that  it  can  be  controlled  by  the  left  arm  and  hand. 

The  chair  should  be  steady,  strong,  and  comfortable,  with  arms  and 
a  good  head-rest  of  rather  a  concave  shape.  It  should  also  have  a  suit- 
able foot-rest.  When  the  regular  dental  chair  is  not  obtainable,  an 
ordinary  strong  wooden  chair  can  be  used.  If  two  of  these  chairs  are 
placed  back  to  back  the  extra  one  gives  a  good  place  for  the  left  foot 
of  the  operator,  and  a  head-rest  may  thus  be  made  of  his  thigh.  The 
patient  should  be  directed  to  grasp  the  seat  at  both  sides  with  his 
hands.  At  times  it  may  be  necessary  to  extract  while  the  patient  is  in 
bed  or  on  an  operating  table ;  in  such  cases  .the  operator  must  obtain 
the  best  position  available.  Where  an  operating  table  or  couch  is  used 
it  is  well,  if  possible,  to  stand  at  the  head  of  the  couch  or  table  and  a 
little  to  one  side  of  the  patient.  By  reaching  over  the  head,  the  for- 
ceps shown  in  Fig.  476  may  be  used  to  advantage  in  work  on  the  lower 
jaw ;  the  same  forceps  may  be  used  for  the  upper  jaw  by  standing  to 
one  side  of  the  patient.  If  the  operator  is  ambidextrous,  so  much  the 
better,  as  it  is  very  advantageous  to  be  able  to  use  the  instrument  in  the 
left  hand,  especially  in  extracting  the  teeth  of  the  right  side  of  the  lower 
jaw.  The  operator  in  this  case  standing  on  the  left  side.  If,  however, 
only  the  right  hand  can  be  used,  the  operator  should,  as  a  rule,  stand  at 
the  right  of  the  chair,  the  left  arm  and  hand  being  used  in  various  ways 
to  control  the  head  of  the  patient.  The  mouth  is  opened  as  far  as 
necessary,  and  the  left  hand  is  then  used  to  hold  the  lips  away  and  keep 
the  jaw  as  steady  as  possible.  (See  Figs.  536  and  537.)  In  using  the 
elevator,  as  shown  in  Figs.  488  and  529,  for  the  removal  of  teeth  from 
the  left  side  of  the  mouth,  especially  for  the  lower  third  molar,  the  oper- 
ator should  stand  on  the  left  side  of  the  patient.  The  index  finger  of 
the  right  hand  should  be  placed  in  the  mouth  by  the  lingual  side  of  the 
tooth,  and  the  thumb  placed  on  the  buccal  side  of  the  first  and  second 
molars.     This  gives  steadiness  to  the  jaw  and  lessens  the  risk  of  slipping. 

Selection  and  Use  of  Instruments. — The  selection  of  instruments 
depends  on  the  nature  of  the  operation  to  be  performed.  The  means 
used  in  extraction  should  be  of  the  most  simple  character.  Many 
deciduous  teeth  and  permanent  teeth  from  about  which  most  of  the 
process  has  been  resorbed  can  often  be  easily  extracted  with  the  thumb 
and  finger.  Children  feel  less  apprehension  with  this  method  than  when 
an  instrument  is  used.     The  thumb  and  fingers  should  be  covered  with 


586 


EXTRACTIOX  OF  TEETH. 


a  napkin,  and  the  tlninil)  placed  on  tlw  inner  surface  of  tJic  tooth  witli 
tlic  tinirors  airainst  the  outside  of  the  jaw.  The  tooth  is  then  forced  out- 
wardly toward  the  elieek  or  lips.  The  roots  of  the  deciduous  teeth  often 
break,  but  this  is  of  little  importance,  for  when  extraction  is  demanded 
the  roots  are  w(>akened  by  the  natural  process  of  resorption  and  will  soon 
disappear.      Elevators  of  the  various  patterns  shown  in  Figs.  488,  489, 

Fig.  529. 


Manner  of  holding  elevator  Fig.  500. 


529,  530,  and  531  should  be  used  whenever  practicable  for  removing 
roots,  and  in  some  cases  teeth  also.  Fig.  488  is  espt'cially  useful  in  re- 
moving the  third  molars,  especially  if  they  be  impacted.  When  the 
internal  anatomy  of  the  jaws  is  well  understood,  this  will  be  appreciated. 


Fig.  530. 


Elevator  in  use  labially. 

Fig.  507  shows  how  firmly  the  roots  are  embraced  at  their  necks 
between  the  two  hard  plates  of  compact  tissue.  It  is  usually  impo.ssible 
to  force  an  instrument  between  the  roots  of  teeth  and  these  plates  with- 


GENERAL  PRINCIPLES. 


587 


out  breaking  the  internal  or  external  walls  of  the  latter.     The  cancel- 
lated tissue  between  these  plates  is,  however,  soft  and  yielding,  and  into 


Elevator  in  use  lingnally. 

this  a  properly  shaped  elevator  can  be  passed  between  the  roots.  After 
pushing  the  instrument  with  the  point  toward  the  root  to  be  extracted 
and  the  back  toward  the  contiguous  tooth  or  root,  using  the  latter  as  a 
fulcrum,  revolve  the  elevator  slightly,  prying  at  the  same  time,  and  the 
root  will  leave  its  socket  with  little  or  no  injury  to  the  surrounding  tis- 
sue. Elevators  should  be  firmly  grasped  and  held  in  such  a  manner 
that  if  a  breakage  or  slip  should  occur  the  instrument  will  be  prevented 
from  wounding  the  soft  tissue.  If  root  forceps  were  used  in  cases  of 
this  kind  it  would  be  almost  impossible  to  avoid  injuring  one  or  the 
other  of  the  plates  when  removing  the  root.  It  is  often  advisable  to 
use  the  forceps  by  passing  the  beaks  between  the  plates  and  grasping 
the  root  on  its  approximal  surfaces,  instead  of  the  external  and  internal 
surfaces.  Even  whole  teeth  may  be  extracted  in  this  way  when  there 
are  no  adjoining  teeth  or  roots.  A  similar  plan  is  sometimes  used  in 
rapid  extracting  under  nitrous  oxid,  where  roots  or  teeth  have  been 
extracted  on  each  side  of  a  tooth,  the  beaks  passing  into  the  sockets 
of  the  extracted  teeth,  thus  grasping  the  tooth  to  be  removed  on  its 
approximal  sides.  This  mode  of  operating  must  be  followed  with 
care,  especially  in  teeth  situated  below  the  maxillary  sinus,  as  the  floor 
of  that  cavity  may  be  easily  injured.     (See  Figs.  504  and  505.) 

Lancing-. — Lancing  for  extraction  is  not  usually  required,  though 
there  are  cases  where  it  is  quite  necessary.     If  the  teeth  have  been 


588 


EXTRACTION  OF  TEETH. 


standing  alone  for  a  long  time,  especially  those  in  the  back  part  of  the 
mouth,  the  gums  are  apt  to  become  firmly  attached  to  them  ;  when  this 
is  the  case  it  is  well  to  sever  the  connecting  tissue  by  the  use  of  the 
lancet  before  extracting.  In  extracting  roots  where  it  is  necessary  to 
remove  a  portion  of  the  external  plate  of  the  alveolar  process,  it  is  well 
to  make  an  incision  in  a  line  over  the  root,  through  the  gum  to  the 
bone  ;  it  is  even  advisable  to  slightly  dissect  the  gum  and  periosteum 
from  the  bone  on  each  side  of  the  cut.  This  is  done  in  order  that  the 
external  beak  of  tlu'  forceps  may  be  passed  along  the  bone  as  far  as  de- 
sired. By  thus  lancing,  the  parts  will  afterward  come  together  and 
quickly  heal,  whereas  if  the  gum  is  cut  by  the  f()rce|)s  it  will  not  heal 
so  well.  In  extracting  roots  in  the  lower  jaw,  if  the  lancing  would 
cause  the  blood  to  cover  the  parts  and  obscure  the  operator's  view  it 
should  be  omitted. 

Use  of  Forceps. — As  nearly  all  operators  are  right-handed,  the 
instruction  as  to  the  use  of  forceps  will  be  given  with  that  understand- 
ing, most  of  the  special  instruments  being  made  for  that  hand.  The 
forceps  are  grasped  in  the  right  hand  with  the  palm  toward  the  body, 
the  thumb  on  top  of  and  partially  between  the  handles  (which  will  indi- 
cate to  a  great  extent  the  amount  of  pressure  being  exerted  upon  the 
tooth),  pressing  against  the  handle  nearest  the  palm  just  back  of  the 
joint.  The  first  finger  should  rest  a  little  between  the  handles,  thus 
giving  a  firmer  grip  on  the  right  handle  (see  Fig.  o;32),  which  might  be 
termed  the  fixed,  or  passive,  handle  ;  Avhile  the  other  one  is  the  movable, 
or  active,  handle.     Many  operators  do  not  place  the  first  finger  between 


Fig.  532. 


Use  of  forceps. 


the  handles  (see  Fig.  533).  The  second  and  third  fingers  pass  to  the 
outside  of  the  left  handle  and  are  used  to  close  the  forceps,  while  the 
little  finger  resting  between  the  handles  is  used  to  open  the  forceps, 
the  thumb  being  used  to  force   the  beaks    into  the  required  position. 


GENERAL  PRINCIPLES.  589 

After  the  forceps  are  in  position  for  extracting,  the  first  finger  is 
placed  along  the  side  of  the  second  finger  to  give  more  power  to 
extract. 

After  it  has  been  decided  to  extract  by  using  the  forceps,  the  par- 
ticular forms  indicated  must  be  selected  and  arranged  in  a  convenient 
place,  ready  for  immediate  use  as  needed.     Especially  should  this  be 

Fig.  533. 


Use  of  forceps. 

the  case  when  the  operation  is  done  under  the  anesthetic  influence  of 
nitrous  oxid.  It  is  under  such  conditions  that  the  fewer  forceps  used 
the  better  ;  the  writer  generally  uses  but  one  forceps  (Fig.  477)  for  the 
extraction  of  any  or  all  teeth  except  the  first  and  second  molars  ;  for 
those  teeth,  when  the  other  teeth  are  in  position,  he  advises  using  the 
special  forceps. 

Having  the  patient's  head  in  position,  the  forceps  are  grasped  as 
previously  described  and  the  beaks  adjusted  to  the  tooth.  As  a  rule, 
the  inner  beak  should  be  placed  in  position  first,  and  then  the  outer 
one — this  is  very  important,  especially  for  the  lower  teeth — taking  care 
not  to  include  a  portion  of  the  tongue  or  the  soft  tissues  of  the  floor 
of  the  mouth,  as  both  are  liable  to  get  in  the  way.  When  the  forceps 
are  adjusted  to  the  inner  and  outer  surfaces  of  the  tooth,  they  should 
be  forced  between  it  and  the  gum  until  they  come  in  contact  with  the 


590  EXTRACTION  OF  TEETH. 

edge  of  the  alveolar  j)r(Kos>.  It  is  a  eomnion  error  of  students  to  use 
too  much  force  in  pressing  the  handles  together;  only  sufficient  force 
should  be  used  to  securely  hold  the  tooth  or  root.  The  forceps  should 
grasp  as  much  of  the  roots  as  possible,  avoiding  pressure  upon  the 
crown  and  being  careful  not  to  force  the  beaks  between  the  alveolar 
plates,  as  this  would  result  in  breaking  one  or  both  plates  over  the 
tooth  or  root  extracted  and  also  over  the  adjoining  tooth.  Cases  have 
occurred  in  which  the  entire  external  plate  of  one  side  has  been  forced 
off  in  this  way. 

At  times  it  may  be  advisable  to  take  away  a  portion  of  the  outer 
plate,  in  which  case  the  lancet  shown  in  Fig.  490  should  be  used  to  cut 
through  the  gum  a  little  beyond  the  point  of  process  to  be  removed, 
dissecting  up  the  gum  slightly  ;  the  inner  beak  is  then  adjusted  and  the 
outer  one  passed  between  the  divided  gum  and  the  process  as  far  as 
required  ;  the  forceps  should  then  be  closed  with  only  sufficient  force 
to  cut  through  the  bone  and  grasp  the  tooth,  taking  care  not  to 
crush  it. 

After  the  forceps  are  in  position  the  tooth  is  loosened  by  rotating  it 
slightly  if  it  be  a  round  conical-rooted  tooth,  such  as  a  central  incisor, 
but  if  it  be  a  flattened  one  it  should  be  removed  by  an  outward  and 
inward  movement. 

By  the  "  out-and-in  motion  "  is  meant  that  after  the  forceps  are  ap- 
plied the  force  used  in  loosening  teeth  is  directed  in  such  a  manner 
that  the  tooth  is  worked  outward  and  inward  from  the  median  line 
of  the  mouth  (see  Fig.  507,  in  which  the  lines  show  the  direction  of 
the  motion  for  each  tooth).  The  individual  teeth  do  not  always  bear 
the  same  relation  to  the  median  line  of  tlie  jaw  as  shown  in  Fig.  507. 
When  the  axis  of  a  tooth  is  not  regular  it  should  be  loosened  by  mov- 
ing backward  and  forward,  and  the  movement  should  be  in  line 
with  its  strongest  diameter,  which  lessens  the  danger  of  breaking  the 
tooth. 

In  the  upper  jaw  the  inward  movement  is  made  after  the  outer,  but 
with  not  so  much  force,  as  the  structure  on  the  inner  side  is  more 
dense. 

Rotation  of  a  tooth  in  extracting  is  seldom  practiced,  as  the  single- 
r(M>ted  teeth  are  usually  flattened  and  teeth  that  have  more  than  one 
root  cannot  be  rotated.  Of  the  single-rooted  teeth,  the  upper  central 
incisors  alone  have  roots  nearly  conical  in  shape  which  permit  rota- 
tion as  well  as  the  out-and-in  motion.  A  rotary  motion  is  usually  of 
advantage  in  extracting  the  roots  of  the  upper  first  bicuspid  when  not 
double,  and  of  the  upper  molars  after  the  crowns  are  broken  away  so 
that  the  roots  are  disunited.  These  roots  are  usually  round,  conical, 
and  somewhat  curved  in  shape. 


GENERAL  PRINCIPLES— DECIDUOUS  TEETH. 


591 


If  possible,  the  tooth  should  be  kept  in  view  during  the  operation 
so  that  the  results  of  the  movements  may  be  seen.  A  beginner  may- 
let  the  forceps  slip  and  extract  the  wrong  tooth  when  he  is  not  observ- 
ing each  movement,  but  an  experienced  operator  can  depend  on  his  sense 
of  touch  to  a  very  great  extent.  The  amount  of  pressure  a  tooth  will 
stand  while  loosening  it  by  an  "out-and-in  motion  "  depends  on  the  size, 
condition,  and  density  of  the  bony  tissue  surrounding  it  and  the  accurate 
fitting  of  the  forceps  to  the  tooth.  Experience  is  the  only  reliable  guide 
in  this  matter.  When  a  tooth  resists  ordinary  eflPort,  if  the  operator  is 
not  quite  sure  of  the  cause  of  the  resistance  of  the  tooth,  it  is  better  to 
desist  temporarily  and  allow  the  patient  to  rest,  in  order  to  investigate 
the  condition  of  the  tooth  and  its  surroundings.  Fig.  519  will  give  some 
idea  of  the  causes  of  the  resistance  offered  by  apparently  normal  crowns. 

After  the  forceps  are  applied  and  the  tooth  slightly  moved,  if  the 
operator  has  a  cultivated  sense  of  touch  he  will  feel  that  the  tooth  is 
yielding  in  one  particular  direction ;  as  a  general  rule  the  tooth  should 
be  carried  in  that  way. 

The  force  applied  to  safely  and  judiciously  extract  teeth  should  be 
made  with  arm  and  wrist  motion ;  if  the  whole  body  is  used  the  sense 
of  touch  is  blunted  and  accidents  are  liable  to  occur. 

Extracting"  Deciduous  Teeth. — In  extracting  the  deciduous  teeth 

Fig.  534. 


Skull  of  a  child  about  six  years  of  age,  showing  all  the  deciduous  teeth  in  position  and  nearly  all 

the  developing  teeth. 

the  principles  involved  are  nearly  the  same  as  for  the  permanent.     A 
care,  however^  must  be  taken  that  is  not  necessary  with  the   perraa- 


692  EXTRACTION  OF  TEETH. 

nent  teeth,  /.  e.,  to  avoid  injurintr  tlie  developing  permanent  teeth  that 
are  situated  ininu'dintoly  beneath  them. 

Fi":.  534  siiows  ;dl  tlie  deeiduous  and  the  deveh)])ing  ])ermanent 
toetli  except  tlie  l()\v(>r  third  molar  arid  tlie  upper  molars.  It  gives 
a  true  idea  of  their  relative  jwsitioiis.  Speeial  attention  is  drawn  to  the 
position  of  the  crowns  of  the  bicuspids  as  related  to  the  deciduous  molars. 
It  will  be  seen  that  they  arc  situated  between  the  roots  of  the  latter  teeth, 
and  bv  usinj;  undue  force  in  adjusting  the  forceps  tiiese  crowns  could 
easily  be  misplaced,  extracted,  or  injured. 

If  the  deciduous  teeth  are  extracted  at  the  proper  time  they  can 
usually  be  removed  by  the  thumb  and  fingers  as  described.  If  not,  one 
of  the  forceps  shown  in  Figs.  476  and  477  should  be  used. 

Extraction   of  Individual   Permanent  Teeth. 

The  anatomv  of  the  individual  teeth  and  the  majority  of  their 
often-repeated  variations  as  well  as  the  general  principles  govern- 
ing the  extracting  operation  being  understood,  the  extraction  of  each 
tooth  will  now  be  studied,  those  of  the  upper  jaw  being  first 
considered. 

The  Upper  Teeth. 
THE   CENTRAI.   INCISOR. 

This  tooth  has  a  strong,  round  conical  root.  The  forceps  are  carried 
into  position  by  placing  the  inner  beak  at  the  palatal  surface  of  the  neck 
of  the  tooth  ;  the  outer  one  is  then  ])laced  in  ])osition  and  the  instru- 
ment forced  upward  with  a  slight  rotary  motion  between  the  gum  and 
the  tooth  until  it  comes  in  contact  with  the  alveolar  process.  As  the 
root  is  round  and  conical,  it  is  loosened  by  rotation  and  the  out-and- 
in  motion  and  then  removed  by  drawing  it  directly  from  its  socket. 
It  is,  as  a  rule,  easily  extracted. 


THE    I.ATERAI>    incisor. 

This  tooth  is  much  smaller  than  the  central.  The  root  is  flattened 
and  somewhat  curved,  the  apex  being  often  bent  in  the  direction 
of  the  canine  teeth.  After  applying  the  forceps  as  directed  for 
the  central  incisor,  the  motion  should  be  outward  and  inward.  As 
the  tooth  has  a  delicate  root,  the  force  used  must  be  light.  When 
loosening  and  removing  it,  care  must  be  exercised,  as  its  root  is  not 
straight.  The  tooth  is  carried  in  the  direction  of  the  least  resistance, 
which  is  usually  toward  the  canine  tooth. 


UPPER   TEETH.  593 

THE    CANINE. 

This  tooth  is  usually  more  firmly  set  in  the  jaw  than  any  other,  and 
it  often  requires  considerable  force  to  break  up  its  attachments.  The 
root  is  long  and  slightly  flattened.  After  applying  the  forceps  its 
attachments  are  broken  up  by  the  out-and-in  motion.  After  loosening 
it  is  usually  easily  removed  from  its  socket.  As  this  tooth  is  erupted 
after  the  adjoining  teeth  are  in  position,  it  is  often  malposed.  If  the 
deciduous  canine  has  been  lost  before  its  proper  time,  and  the  first 
bicuspid  has  pushed  forward,  there  is  no  room  for  the  canine  to  take 
its  true  position.  This  irregularity  varies  to  a  great  extent.  The 
canine  may  also  be  out  of  position  from  unknown  causes.  A  marked 
specimen  is  seen  in  Fig.  528,  where  both  canines  are  impacted.  They 
were  entirely  covered  by  a  bony  lamina. 

Sometimes  the  roots  of  these  teeth  project  into  the  maxillary  sinus, 
or  even  into  the  nasal  chamber,  while  the  crowns  are  impacted  be- 
tween the  palatal  plate  and  the  plate  forming 
the  floor  of  the   nose.      Fig.  535    represents  a  ^^' 

canine,  lateral,  and  central  incisor  which  were 
extracted  from  the  sinus,  the  roots  being 
imbedded  in  its  inner  wall.  Teeth  thus  im- 
pacted are  often  a  source  of  trouble  in  vari- 
ous  ways   and   when   discovered  should   be   re- 

,        ,^^,  ,  ,      .  Ill  Canine,  lateral,  and  central 

moved.  When  the  tooth  is  so  covered  by  bone  incisor  extracted  from 
that   the    forceps   cannot   be    applied   the    bone         maxiiiary   sinus    thai 

■■■  _  ^  ^  were  causing  neuralgia. 

must  be  cut  away  sufficiently  to  allow  the  forceps 

to  grasp  it.  A  very  good  instrument  for  removing  the  bone  in  the 
upper  jaw  is  the  elevator  shown  in  Fig.  488 ;  after  the  point  has  been 
sharpened  it  may  be  used  as  a  chisel  or  gouge. 

THE    BICUSPIDS. 

The  first  bicuspid  usually  has  a  bifurcated  root  and  the  only  motion 
that  can  be  used  safely  for  loosening  is  the  out-and-in,  as  these  roots  are 
sometimes  considerably  divergent.  The  removal  after  loosening  is  not 
always  easily  accomplished,  a  little  outward  pressure  being  frequently 
necessary.  If  the  force  required  is  used  too  suddenly  the  inner  root  is 
liable  to  break. 

The  second  bicuspid  usually  has  a  single  flattened  root,  though  occa- 
sionally it  is  bifurcated.  The  motion  used  to  loosen  this  tooth  is  the 
outward  and  inward,  using  the  same  precaution  as  with  the  first  bicus- 
pid on  account  of  the  possibility  of  a  double  root. 


38 


504 


EXTRACTION  OF  TEETH. 


THE    FIRST    AND    SK(X)NI)    MOLARS. 

These  teeth  are  nearly  similar,  havini;  three  roots,  two  bueeal  and 
one  palatal,  whieh  vary  so  much  in  degrees  of  separation  that  no  set 
rule  can  be  given  for  their  extraction.  The  roots  of  the  first  are  usually 
more  divergent  than  those  of  the  second.  Only  the  out-and-in  motion 
can  be  used,  rotation  being  out  of  the  question   in   loosening  them,  as 

Fig.  5;)0. 


Showing  position  for  extracting  upper  teeth  of  left  side. 

the  roots  often  diverge  to  a  great  extent.  (See  p,  Fig.  527.)  After  the 
tooth  has  been  loosened  there  is  at  times  a  difficulty  in  removing  it, 
on  account  of  the  distance  around  the  three  roots ;  owing  to  their 
divergence  this  distance  is  greater  than  the  size  of  the  anatomical 
neck  of  the  tooth  corresponding  to  the  opening  of  the  socket.  The 
only  general  rule  that  can  be  given  is  to  carry  it  in  the  direction  of 


THE   UPPER   TEETH. 


595 


the  least  resistance.  Each  tooth  has  more  or  less  of  an  individual 
character,  and  therefore  the  operator  must  be  governed  by  circum- 
stances. The  main  precaution  to  be  observed  is  not  to  be  in  too 
great  haste,  as  there  is  danger  of  breaking  one  of  the  roots  or  re- 
moving a  large  piece  of  the  outer  plate  of  the  alveolar  process.  (See 
Accidents,  p.  612.) 

THE    THIRD    MOLAE. 

This  tooth  so  varies  as  to  the  shape  and  number  of  its  roots  that  it 
is  seldom  spoken  of  as  an  abnormal  tooth,  no  matter  in  what  form  or 
position  it  may  be  found  ;  the  greater  number  have  roots  curved  back- 
ward and  outward.  Their  position  in  the  jaw  also  varies  considerably. 
The  forceps  shown  in  Fig.  476  is  the  instrument  to  use  in  extracting. 
After  the  forceps  have  been  firmly  placed,  the  principal  motion  is  the 
out-and-in,  though  more  out  than  in.  If  there  is  mucli  resistance  the 
hand  should  be  carried  outward  and  upward,  or  in  the  direction  of  the 
least  resistance.     This  tooth  is  sometimes  erupted  at  the  side  of  the 

Fig.  537. 


Showing  position  for  extracting  upper  tetth  of  right  side. 


alveolar  process  (Fig.  538)  with  its  occlusal  surface  pointing  toward  the 
cheek.  It  is  not  well  to  have  the  mouth  opened  too  far,  as  it  brings  the 
coronoid  process  of  the  lower  jaw  in  the  way. 

In  stating  the  general  rules  of  extracting,  caution  was  given  not  to 
niake  the  movements  faster  than  could  be  seen ;  this  applies  very  partic- 
ularly to  the  third  molar.      It  is  so  near  the  ascending  ramus  in  the 


596 


EXTRACTION  OF  THE  TEETH. 


lower  jaw  that  it  is  possiMc,  ospocially  when  the  roots  are  curved  aiul 
spread  out,  to  t'raetiire  this  aii<rle,  or  in  the  u|)per  jaw  the  tuherosity  may 
be  broken  away,  thus  openiiiu-  into  the  maxillary  sinus.  The  <;um  tis- 
sue often  adheres  to  the  posterior  portion  of  this  tooth;  when  this  hap- 


Fk;.  .",;«. 


An  impacted  upper  third  molar.    A  similar  cuinlition  found  on  tlie  opposite  side  of  the  skull. 

pens  it  is  best  to  desist  from  attempts  at  extraction  and  sever  the  tissue 
from  it  with  a  curved  lancet  or  scissors  before  removing  the  tooth  with 
the  forceps,  or,  as  before  advised,  dissect  the  gum  away  before  applying 
the  forceps. 

The  Lower  Teeth. 

As  a  rule,  the  teeth  of  the  lower  jaw^  are  more  difficult  to  extract 
than  are  those  of  the  upper  jaw,  the  lips  and  cheeks  being  in  the  Avay. 
The  tongue  is  also  troublesome,  covering  the  tooth,  and  when  the  inner 
beak  of  the  forceps  is  placed  in  position  especial  care  must  be  used  to 
prevent  part  of  the  tongue  or  floor  of  the  mouth  from  being  caught  in 
the  instrument. 

THE  ORAL  OR  ANTERIOR  TEETH. 

(For  position  see  Fig.  539.) 

These  six  teeth  have  small  single,  straight,  compressed  roots.  Their 
extraction  is  only  necessary  when  they  become  loosened  by  accident  or 
from  disease  or  when  it  is  necessary  to  clear  the  mouth  for  inserting 
artificial  teeth.  The  operator  should  stand  a  little  back  and  to  the 
right  side  of  the  chair,  being  somewhat  elevated  above  the  usual  ])osi- 
tion.  Pass  the  first  finger  of  the  left  hand  between  the  lips  and  the 
alveolar  border,  and  place  the  remaining  fingers  beneath  the  chin  with 
the  thunib  on  the  inside  of  the  teeth.     For  the  incisors  use  the  lower 


THE  LOWER   TEETH. 


597 


root  forceps  shown  in  Fig.  487  or  the  universal  forceps  shown  in  Fig. 
477.     The  canines  are  larger  and  more  firmly  set ;  delicate  root  forceps, 
therefore,  are  not  usually  suitable ;  the  instrument  shown  in  Fig.  477  or, 
better,  the  bicuspid  forceps  (Fig.  485)  are  much  to  be  preferred. 
An  out-and-in  motion  is  proper  for  loosening  all  these  teeth. 

Fig.  539. 


Showing  position  for  extracting  lower  anterior  teeth. 


THE    BICUSPIDS. 

The  lower  bicuspids  have  compressed  roots  seldom  bifurcated,  and 
are  generally  extracted  by  the  out-and-in  motion.  The  special  forceps 
for  these  teeth  should  be  made  so  that  they  grasp  a  considerable  por- 
tion of  the  surface  of  the  tooth.  Tliese  teeth  are  often  difficult  to 
extract  without  breaking  when  all  the  teeth  are  in  position,  the  roots 


598 


EXTRACTION  OF  TEETH. 


being  long  and  narrow  and  often  situated  in  an  awkward  j)<)sition.  As 
shown  in  Fig.  506,  the  position  of  the  roots  of  the  second  bicuspid  is 
a  littk'  to  tlio  inner  side  of  the  anterior  root  of  the  first  niohir.  The 
tooth  ilhistrated  in  this  particular  case  would  be  very  difficult  to  extract 
without  breaking. 

THE    FIRST    MOLAR. 

(For  position  see  Fig.  540  for  the  left  side,  541  for  the  right  side.) 
The  first  molar,  if  in  a  mouth  where  all  the  teeth  are  in  position,  is 
generally  the  most  difficidt  of  all  the  teeth  to  extract.  The  roots  are 
usually  long  and  diverging.  Tt  is  lower  in  the  arch  than  the  other 
teeth,  and  is  in  fact  similar  to  an  inverted  keystone ;  consequently, 
when  extracted  it  is  drawn  through  the  arch.  When  the  teeth  are  close 
together  the  second  bicuspid  and  second  molar  yield  a  little,  but  great 
care  must  be  taken  that  one  or  both  of  these  teeth  are  not  extracted 

Fig.  540. 


Showing  position  for  extracting  lower  tuetli  of  tlie  left  side. 


with  the  fir.st  molar.  In  placing  the  forceps  on  the  lower  molars  the 
points  of  the  beaks  of  the  special  molar  forceps  (Fig.  473  or  486)  are 
placed  in  between  the  roots  on  each  side  of  the  tooth.  Care  should 
be  exercised  to  avoid  including  a  portion  of  the  tongue  or  soft  tissues 
of  the  floor  of  the  mouth  in  the  forceps.  If  the  forceps  are  not  well 
placed  the  wrong  tooth  may  be  extracted,  as  it  is  possible  for  them  to 
slip  in  between  two  teeth. 


THE  LOWER  TEETH.  599 

In  loosening  these  teeth  the  out-aud-in  motion  is  used,  and  as  they  are 
wedged  in  it  is  often  necessary  to  continue  this  motion  while  extracting 
them  from  their  sockets.    At  times  it  is  advisable  to  move  the  tooth  out- 

FiG.  541. 


Showing  position  for  extracting  lower  teeth  of  the  right  side. 


wardly  after  it  has  been  slightly  lifted  from  its  socket.  Occasionally  the 
roots  diverge  so  far  that  either  the  crown  has  to  be  broken  from  the 
roots  at  their  bifurcation  or  the  tooth  divided  in  the  line  of  bifurcation 
with  splitting  forceps ;  each  root  being  then  extracted  separately. 

THE   SECOND    MOLAE. 

The  roots  of  this  tooth  are  not  as  diverging  as  those  of  the  first 
molar,  as  may  be  seen  by  examining  Fig.  502,  nor  is  the  tooth  wedged 
in  as  tightly  as  in  the  case  of  the  first  molar. 

The  out-and-in  motion  is  required  for  these  teeth,  using  the  same 
precautions  that  are  necessary  in  the  extraction  of  the  first  molar. 

THE    THIED    MOLAE. 

In  this  tooth  the  roots  may  vary  so  much  in  number  and  shape  that 
it  can  hardly  be  said  to  be  a  typical  third  molar.  Fig.  502  shows  what 
might  be  called  a  typical  third  molar,  but  these  are  only  found  in  well- 
developed  jaws,  where  the  teeth  are  not  so  large  as  to  cause  crowding,  or 
where  there  has  been  no  inflammatory  condition  causing  excessive  deposit 


600  EXTRACTION  OF  TEETH. 

of  lime  salts  witliiii  the  canct'llatcd  tissue.  Tlicy  vary  in  character  from 
the  one  sliowu  in  Fig.  502  tt>  those  shown  in  Figs.  513  to  524  inehisive. 
There  are  also  third  molars  having  three,  four,  or  live  roots.  I'^ig.  527,  a 
shows  another  form  of  the  third  molar;  h,  c,  d,  c,  and  /show  where  the 
third  molar  has  united  ■with  the  second  molar;  </ and  h  illustrate  three 
molars  united;  /, /,  /:,  l,m,  n,  o,  and  p  show  variations  of  roots.  The 
positions  these  teeth  oceupv  may  vary  in  all  degrees  from  that  shown  in 
Fig,  502  to  those  shown  in  Figs.  513  to  524  inclusive. 

Where  the  third  molar  is  in  the  position  shown  in  Fig.  502  and  there 
are  no  other  complications,  its  extraction  is  easy.  The  tooth  is  remitved 
bv  placing  either  the  special  lower  molar  forceps  shown  in  Fig.  4.S(J  or 
the  forceps  shown  in  Figs.  476  and  477  in  j)osition,  and  using  the  out- 
and-in  motion  with  a  slight  raising  of  handles.  If  Fig.  47(J  be  used  the 
beaks  should  be  turned  downward  and  the  handles  carried  upward. 
But  when  it  is  of  irregular  form  and  position,  as  shown  in  the  various 
illustrations,  the  ditiieulty  increases  with  the  degree  of  variance  from 
that  of  the  typical  tooth  showii  in  Fig.  502.  These  cases  should  be 
closely  studied.  If  portions  of  the  teeth  are  in  view,  as  .shown  in  Figs. 
519  and  520,  they  will  assist  to  some  extent  in  the  diagnosis  of  the 
position  of  the  roots.  In  this  particular  case,  the  bone  as  well  as  the 
roots  being  much  hypertrophied,  it  would  be  impossible  to  extract  the 
roots  without  fracturing  the  process  to  a  greater  or  less  extent.  It  will 
be  noticed,  on  examining  the  section  Fig.  519,  that  to  have  fractured  the 
inner  portion  of  the  jaw,  the  inferior  dental  nerve  and  vessels  and  also 
the  mylo-hyoid  nerve  and  vessels  would  be  endangered.  If  in  attempt- 
ing to  extract  this  tooth  it  should  not  yield  to  a  pressure  which  if  in- 
creased would  break  the  bone,  it  is  better  to  desist  and  cut  away  the  bone 
with  a  bur  (shown  in  Fig.  582)  in  the  surgical  engine,  as  was  done  in  the 
case  of  the  specimen  from  which  the  illustration  was  made.  Those  rep- 
resented in  Figs.  515,  516,  517,  and  518  are  uncommon  cases  and  would 
be  more  difficult  to  diagnosticate,  as  no  portion  of  the  teeth  was  in  view. 

Usually  a  satisfactory  diagnosis  of  their  position  can  be  made  by  the 
use  of  a  properly  shajied  excavator,  especially  by  those  who  are  experi- 
enced in  the  handling  of  such  an  instrument  and  who  are  thoroughly  con- 
versant with  the  normal  and  ])atliol()gical  anatomy  of  these  ]>arts  and 
recognize  the  pathological  symptoms  that  are  indicated.  Xo  one  without 
this  knowledge  is  properly  equipped  to  diagnose  teeth  in  this  position,  much 
less  to  extract  them.  An  X-ray  picture  may  be  of  service,  especially  in  the 
absence  of  this  knowledge  of  the  general  ])rinciples  of  the  diseases  of  the 
jaws  and  face.  After  making  the  diagnosis  of  an  impacted  tooth  in  such 
a  position,  if  it  is  to  be  removed  the  operation  should  be  done  in  the 
hospital,  the  patient  should  be  anesthetized  by  ether,  and,  as  in  all  ex- 
tractions of  teeth,  the  same  antiseptic  precautions  should  be  taken  as  are 
used  in  general  surgical  operations.     Then  by  the  removal  of  the  soft 


THE  LOWER   TEETH. 


601 


tissue  by  a  small  curved  knife  and  the  use  of  proper  burs,  driven  by  the 
surgical  engine,  the  tooth  can  be  liberated  from  its  bony  prison. 

Figs.  521  and  523  show  more  common  forms  of  impacted  lower  third 
molars  and  are  comparatively  easy  to  diagnose. 

The  following  description  will  cover  the  general  procedure  of  extract- 
ing ordinary  forms  of  impacted  lower  third  molars,  except  that  in  a  few 
cases  it  will  not  be  necessary  to  cut  the  crown. 

Fig.  542. 


Showing  two  impacted  lower  third  molars. 


Fig.  542  is  an  illustration  of  two  impacted  lower  third  molars. 
Part  of  the  crown  of  the  left  lower  third  molar  was  broken  away  in  an 
endeavor  to  extract  the  tooth,  leaving  the  pulp  exposed.  By  careful  ex- 
amination with  an  excavator  it  was  found  that  the  anterior  cusps  were 
interlocked  within  the  concave  portion  of  the  distal  surface  of  the  second 
molar,  and  were  so  far  down  in  the  tissue  that  a  carborundum  disk  could 
not  be  used  to  remove  them.  The  patient  being  etherized,  a  mouth-gag 
was  placed  in  position,  and  a  portion  of  the  soft  tissue  removed  with  a 
small  knife.      The  revolving   spiral  osteotome  (Fig.  543)  was  placed 


(i02 


EXTRACTION   OF  TEETH. 


Fio.  54:.. 


witliin  the  broken  c^rowii  or  into  tlie  juilj)  clKunber,  cutting  almost 
througli  the  balance  of  the  crown.  Then  by  passing  the  point  of  the 
osteotome  under  the  crown  and  between  it  and  the  bone,  a  space  was 
made  in  the  tootli  and  in  the  bone,  whicii  allowed  the 
point  of  the  elevator,  shown  in  Figs.  488  and  529,  to  pass 
l)etween  the  tooth  and  the  jaw. 

The  writer  uow  seldom  uses  the  forceps  to  remove  a 
tooth  alter  loosening  it  witli  the  elevator.  In  using  the 
elevator  on  tiie  left  side,  as  in  this  case,  it  is  operated  with 
the  right  hand,  the  surgeon  standing  on  the  left  side  of 
tlie  patient.  The  left  forefinger  is  placed  in  the  mouth, 
by  the  lingual  side  of  the  tooth,  and  the  thumb  is  placed 
on  the  buccal  side  of  the  first  and  second  molars.  This 
gives  steadiness  to  the  jaw  and  lessens  the  risk  of  slipping. 
As  the  tooth  is  raised  from  its  socket,  the  forefinger  is 
placed  so  as  to  bring  the  tooth  out  of  the  mouth.  If  the 
tooth  to  be  removed  is  on  the  right  side,  the  elevator 
should  be  used  with  the  left  hand  if  possible  (the  surgeon 
standing  (m  the  right  side).  If  the  operator  must  use 
the  elevator  with  his  right  hand  he  should,  however,  manage  to  guard 
and  steady  the  parts  with  his  left  hand. 

Fig.  544  is  made  from  three  photographs  of  the  tooth  after  extraction. 
A  shows  the  outer  or  buccal  side  of  its  roots,  in  about  the  same  position 
as  when  in  the  jaw.     The  distal  cusps  were  broken  away  in  a  former 

Fig.  544. 


Two  forms  i.f 
Cryer's  spiral 
osteotome. 


A  B  c 

Showing  three  views  of  the  tooth  extracted  from  the  left  side  of  Fig.  342. 

endeavor  to  extract  it.  The  greater  portion  of  the  crown  was  cut  away 
with  the  surgical  engine.  On  the  side  of  the  tooth  there  is  a  groove 
extending  backward,  downward,  and  inward,  cut  by  the  osteotome.  It 
was  along  this  groove  tliat  the  elevator  was  forced  under  the  tooth,  caus- 
ing the  slight  remaining  portion  of  the  crown  to  fracture.  In  B  the  tooth 
is  turned  slightly  outw-ard,  in  order  to  show  three  roots  and  the  line  of 
fracture  which  liberated  the  tooth.  In  c  the  tooth  is  turned  upon  its 
buccal  surface,  showing  the  two  anterior  cusps  which  were  locked  under 
the  distal  surface  of  the  second  molar. 

In  Fig.  513  tlie  third  molar  is  in  such  position  as  to  be  easily  ex- 
tracted, though  if  proper  care  were  not  used  the  extraction  might  have 
serious  consequences.  It  will  be  noticed  that  the  points  of  the  roots  are 
just  through  the  inner  U-shaped  cortical  portion  of  the  lower  jaw  below 


THE  LOWER   TEETH. 


603 


the  mylo-hyoid  ridge  and  project  into  the  submaxillary  region.  Now, 
should  this  tooth  or  the  roots  be  pushed  downward  in  attempted  ex- 
tracting, as  is  sometimes  taught,  it  might  be  forced  into  the  submaxillary 
region  and  consequently  be  lost  for  a  time,  with  the  possibility  of  having 
to  perform  a  subsequent  surgical  operation  to  cut  it  out  from  the  neck. 

An  impacted  third  molar  often  causes  great  distress  by  initiating  an 
inflammation  which  extends  to  the  region  surrounding  the  angle  of  the 
jaw,  and  often  including  the  temporo-maxillary  articulation  and  soft 
parts  within  the  mouth.  Under  these  conditions  the  jaws  can  only  be 
partly  opened,  deglutition  is  impaired,  and  solid  food  cannot  be  taken. 
If  any  part  of  the  tooth  can  be  seen,  the  difficulty  is  not  so  great.  Relief 
must  be  given,  and,  as  a  general  rule,  the  offending  tooth  should  be  ex- 
tracted. Circumstances  may  arise  in  which  the  removal  of  the  second 
molar  may  become  an  unavoidable  preliminary  to  the  removal  of  the 
third  molar.     As  the  mouth  can  only  be  opened  slightly,  it  is  impossible 

Fig.  545. 


Showing  the  direction  in  wliicli  the  lower  third  molar  is  to  be  extracted. 

to  use  the  large  special  molar  forceps.  An  elevator  is  sometimes  recom- 
mended in  these  cases,  but  it  may  prove  to  be  a  dangerous  instrument 
to  use  under  such  conditions,  for  when  the  tooth  is  lifted  out  of  its  posi- 
tion in  the  mouth,  it  might  slip  back  into  the  larynx.  It  is  well  in  some 
cases  to  loosen  a  tooth  with  an  elevator  and  then  remove  it  with  the 
forceps  shown  in  Figs.  476  or  477,  as  they  are  small  and  are  so  shaped 
that  the  beaks  can  be  carried  back  to  the  tooth  mainly  along  the  vesti- 
bule of  the  mouth,  the  inner  blade  being  placed  between  the  teeth  by 
passing  the  forceps  back  of  the  second  molar.  Often  it  is  impossible 
to  see  completely  what  is  being  done ;  therefore,  it  is  not  well  for  a 
beginner  to  undertake  this  kind  of  extracting.  After  the  forceps  is 
in  position  the  tooth  should  be  worked  in  any  direction  in  which  it 
will  yield ;  this  is  generally  outward,  upward,  and  backward,  in  the 
manner  of  unfastening   a   hook.      (See   Fig.  545.)      When   the  lower 


604  EXTRACTION  OF  TEETH. 

third  molar  is  impacted  near  the  gonion  or  external  angle  of  the  jaw,  it 
may  be  n(^cossary  to  open  it  from  the  outside  through  the  soft  tissues. 
When  such  is  the  case  the  surgical  engine  should  be  used  for  cutting 
the  bone. 

Treatment  after  Extraction. 

The  operator  should  recognize  immediately  any  accident  that  may 
have  happened  during  the  operation  of  extraction,  and  treat  it  as  the 
circumstances  indicate  ;  but  if  nothing  unusual  ocvurs,  then  the  |)atient 
may  be  allowed  a  few  moments'  rest,  after  which  the  mouth  should  be 
carefully  examined.  If  there  be  any  loose  portions  of  the  process  or 
pieces  of  gum  hanging  to  the  parts  operated  upon,  they  should  be  re- 
moved by  any  convenient  means,  such  as  small  forceps,  a  curved  pair  of 
scissors,  or  a  curved  lancet  (Figs.  490  and  492). 

When  several  teeth  have  been  extracted,  leaving  ragged  edges  of  the 
outer  walls  of  the  alveolar  process,  these  should  be  removed  with  the 
excising  forceps  or,  better  still,  by  the  use  of  either  forceps  Fig.  476  or 
477,  according  to  circumstances,  as  the  beaks  can  be  carried  between  the 
gum  and  the  process  better  than  can  the  blades  of  the  excising  forceps. 

An  antiseptic  mouth-wash  consisting  of  a  tablespoonful  of  phenol 
sodique  to  a  glass  of  water  should  be  used  several  times  daily  for  the 
next  few  days.  Any  other  suitable  antiseptic  mouth-wash  which  may 
be  more  agreeable  to  the  patient  may  be  used  instead,  though  the  phenol 
sodique  is  highly  efficacious. 

Occasionally,  in  a  few  days  after  extraction,  pain  will  be  noticed  in 
and  about  the  alveolus,  especially  when  the  tooth  has  been  the  seat  of 
pericemental  inflammation.  Relief  in  such  a  case  is  usually  given  by 
removing  any  clot  that  may  have  formed,  and  breaking  down  the  de- 
generated tissues  which  should  have  adhered  to  the  root.  A  pledget  of 
cotton  saturated  with  the  full-strength  solution  of  phenol  sodique  or 
campho-phenique  should  then  be  inserted  as  a  dressing. 

Accidents. 

When  accidents  of  any  kind  whatever  occur,  the  operator  should  be 
calm  and  appear  perfect  master  of  the  situation.  He  should  be  pre- 
pared to  successfully  deal  witli  whatever  conditions  may  arise. 

One  of  the  most  common  accidents  is  the  breaking  of  a  whole  or 
portion  of  a  tooth  or  root.  If  the  operator  has  any  doubt  of  his  ability 
to  remove  the  tooth  entire,  he  should  inform  the  patient  that  there  is  a 
possibility  of  its  breaking,  in  which  case  not  to  be  alarmed.  If  the 
tooth  is  removed  without  breakage  so  much  the  better ;  even  if  it  does 
break  it  will  not  cause  alarm  to  the  patient.  It  is  more  desirable  that 
all  of  a  tooth  should  be  removed,  for  if  its  surrounding  membrane  has 


ACCIDENTS. 


605 


been  inflamed,  or  if  a  root  having  a  portion  of  the  pulp  attached  has 
been  broken,  either  will  be  the  source  of  obstinate  pain. 

It  is  better,  however,  under  some  circumstances  to  let  certain  roots 
remain  if  they  are  broken  than  to  break  away  a  large  amount  of  process. 
Roots  are  sometimes  so  situated  that  they  can  be  easily  forced  into  the 
maxillary  sinus  (see  Figs.  504  and  505),  or  into  the  submaxillary  region 
(see  Fig.  513),  or  upon  the  inferior  dental  nerve.  If  there  exist 
reasons  for  believing  that  the  root  will  not  cause  undue  pain,  and  there 


Fig.  546. 


Fig.  547. 


Fig.  548. 


Fig.  549. 


Fig.  552. 


Fig.  550. 


Fig.  553. 


Fig.  551. 


Fig.  554. 


be  danger  of  breaking  a  large  amount  of  process,  it  is  preferable  to  let 
it  remain,  as  in  a  short  time  the  contraction  of  the  soft  parts  and  their 
expulsive  efforts  will  force  the  root  outward,  and  it  can  then  be  removed 
without  danger.  If  roots  are  forced  into  i\\e  maxillary  sinus  they  must 
be  followed  and  removed. 

When  several  teeth  are  to  be  extracted  under  an  anesthetic,  if  the 
gum  should  adhere  unduly  to  one  of  them,  the  operator  should  desist 
from  its  removal  and  proceed  with  the  other  extractions,  after  which 
the  adherent  gum  should  be  severed  with  a  curved  lancet  or  a  pair  of 
curved  scissors  and  the  tooth  then  removed.  If  the  gum  be  much 
torn  and  the  bone  exposed  to  a  great  extent,  it  should  be  held  in  place 


606  EXTRACTION  OF  TEETH. 

by  a  few  interrupted  sutures.  If,  however,  proper  care  be  taken  in 
extractiufr,  tliis  should  not  occur. 

In  extracting  crowded  teeth,  or  those  haviug  Irail  alveolar  surround- 
ings, it  is  possible  to  remove  a  piece  of  the  alveolar  plate,  especially  in 
extracting  the  first  and  second  molars,  the  broken  piece  extending  back- 
ward, forward,  or  in  both  directions  to  the  adjoining  tooth.  (8ee  Figs. 
546  to  554.)  The  tooth  in  front  may  even  be  }>artially  lifted  from 
its  socket.  As  soon  as  the  operator  sees  the  impending  accident  he 
should  either  stop  and  see  if  his  method  of  extraction  could  be  im- 
proved, or,  this  j)oint  being  negatively  decided,  hold  the  parts  in  posi- 
tion with  the  left  hand  as  well  as  he  can,  and  after  the  tooth  is  removed 
force  the  injured  j>arts  into  position  ;  they  will  usually  stay,  but  if  not, 
appliances  of  appropriate  form  can  be  used  for  retention. 

In  extracting  the  upper  third  molar,  the  tuberosity  is  sometimes 
broken  away,  opening  into  the  maxillary  sinus  (see  Figs.  546,  547,  548, 
551,  and  554,  showing  where  teeth  have  been  carried  away  with  the 
tuberosity).  If  it  is  a  simple  fracture  the  parts  can  be  forced  into  place 
and  they  will  in  a  short  time  reunite.  But  if  the  parts  are  torn  loose  it 
will  be  of  little  use  to  try  to  replace  them  ;  the  best  course  is  to  trim 
away  the  ragged  edges,  using  the  curved  scissors  for  this  purpose. 

After  such  a  fracture  it  is  possible  that  hemorrhage  may  occur  from 
rupture  of  the  superior  dental  artery.  This  is  sometimes  difficult  to 
control.  One  of  the  best  remedies,  however,  is  to  tightly  pack  the  parts 
with  medicated  gauze.  This  application  must  be  left  in  for  a  few  days 
and  then  be  carefully  removed.  It  is  sometimes  well  to  take  out  only 
part  of  the  gauze  at  a  time,  the  loosened  portions  being  cut  off  with  a 
pair  of  curved  scissors.  Hemorrhage  after  extraction  usually  ceases  in 
a  short  time,  and  then  there  is  no  occasion  for  treatment ;  when,  how- 
ever, the  adjoining  parts  are  much  inflamed,  or  the  patient  is  in  an 
anemic  condition,  or  the  case  is  one  of  hemorrhagic  diathesis,  special 
treatment  will  be  necessary. 

Hemorrhage  of  extraction  may  be  divided  into  two  classes,  arterial 
and  capillary.  AVhen  arterial,  it  is  usually  located  in  the  socket  of 
the  tooth,  and  may  usually  be  stopped  without  much  difficulty  by  taking 
a  twist  of  absorbent  cotton,  shaping  it  into  a  thin  tapering  roll,  and 
thoroughly  packing  the  socket.  Before  inserting  the  cotton  tampon, 
it  should  be  rolled  in  tannic  acid  until  the  fibers  will  hold  no  more, 
then  the  cotton  is  to  be  packed  tightly  into  the  alveolus  with  a  dental 
plugger.  In  packing  the  cotton  it  is  well  to  begin  at  one  end  and 
fcrimp  it  upon  itself  until  the  socket  is  entirely  filled.  The  plug  in  a  few 
cases  may  require  retention  in  position  by  compression.  This  is  accom- 
plished by  holding  a  few  folds  of  muslin  or  similar  material  over  the  plug, 
closing  the  mouth  and  binding  the  jaws  together  with  a  few  turns  of  a 


ACCIDENTS. 


607 


Barton's  bandage.  (See  Fig.  555.)  The  25  per  cent,  ethereal  solution 
of  hydrogen  dioxid  in  small  quantity  on  cotton  packed  into  a  bleeding 
socket  is  a  most  efficient  styptic,  and  will  effectually  control  severe  hem- 
orrhage after  extraction.  Care  must  be  exercised  not  to  use  the  solution 
in  excess,  as  it  may  cause  injury  to  adjacent  parts. 

Where  hemorrhage  occurs  from  the  surrounding  tissue,  as  in  patients 
in  an  anemic  condition  or  in  cases  of  hemorrhagic  diathesis,  the  case 
usually  falls  into  the  hands  of  a  general  practitioner  for  systemic 
treatment,  but  the  local  treatment  usually  employed  bv  physicians  in 
these  cases  is  often  unsatisfactory,  many  using  Monsel's  solution  of 
persulfate  of  iron,  which,  although  it  may  be  a  good  styptic  for  use  in 

Fig.  555. 


Barton's  head  bandage. 

other  parts  of  the  body,  should  not  be  used  in  the  mouth.  The  local 
treatment  in  such  cases,  whether  soon  after  extracting  or  not,  is  first 
to  remove  all  clots  from  the  wound  and  find  the  exact  place  or  places 
from  which  the  blood  is  exuding.  A  suitable  styptic  and  compression 
are  the  principal  means  used  for  stopping  it,  the  latter  perhaps  being 
the  most  important.  Tannic  acid  applied  on  cotton,  lint,  or  similar 
substances  is  a  good  styptic  to  use  in  the 
mouth.  Compression  can  be  applied  as  the 
ingenuity  of  the  operator  may  direct.  When 
a  hemorrhage  occurs  from  a  socket  between 
sound  teeth,  it  can  be  readily  controlled  by  two 
ligatures,  making  one  fast  to  each  tooth,  then 
placing  in  position  and  tying  the  four  ends  to- 
gether over  the  compress,  as  shown  in  Fig.  556. 
In  a  few  rare  cases  an  impression  of  the  parts  should  be  taken  in  wax 
or  modelling  compound  in  order  that  a  vulcanite  or  metallic  plate  can 


Fig.  556. 


Showiiiij  ('(iDiprcssaiKl  liu-atures. 


608  EXTRACTION  OF  TEETH. 

be  made  to  hold  the  styptic  compress  in  position.  After  the  com- 
press is  in  position  warmed  modelling;  compound  can  be  ])laced  over  it 
and  the  jaws  bron<;ht  together  and  retained  in  pUice  by  a  head  bandage. 
A  phig  of  hardening  plaster  of  Paris  may  be  made  and  forced  into 
the  bleeding  socket  in  obstinate  cases,  or  in  exircmia  the  extracted  tooth 
might  be  soaked  well  in  phunol  sodique  and  reinserted. 

The  systemic  treatment  is  often  important ;  if  the  patient  is  seen 
to  be  anemic  or  known  to  be  of  the  hemorrhagic  diathesis,  the  treat- 
ment should  be  Ix'gun  before  extracting.  This  is  done  in'  thoroughly 
building  up  the  system  by  a  course  of  hygienic  and  tonic  treatment. 
The  cause  of  bleeding  in  cases  Avhere  the  hemorrhagic  diathesis  exists 
is  but  imperfectly  understood  ;  the  blood  may  be  so  defibrinated  that  it 
has  lost  the  power  of  coagulation  and  so  will  not  form  a  clot,  or  the 
muscular  coats  of  the  vessels  have  lost  their  tonicity,  either  through 
general  debility  or  the  lack  of  energy  in  the  vasomotor  nervous  system, 
which  prevents  their  contracting  so  as  to  close  the  lumen.  Certainly 
the  walls  of  the  capillaries  permit  free  transudation  of  the  blood. 
In  good  health  the  proper  coagulation  and  the  contraction  of  the  blood- 
vessels will  stop  tile  hemorrhage  even  when  an  artery  of  consider- 
able size  is  lacerated,  especially  if  the  flow  be  held  in  abeyance  by  arti- 
ficial means  for  a  short  time.  It  is  when  the  blood  will  not  coagulate 
and  the  vessels  fail  to  contract  that  a  thorougii  systemic  treatment  must 
be  given.  This  lack  of  normal  function  on  the  part  of  the  blood  and 
vessels  may  arise  from  various  diseases,  and  in  order  to  judiciously 
treat  a  patient  exhibiting  the  hemorrhagic  diathesis  a  thorough  exam- 
ination must  be  made  and  such  treatment  given  as  the  diagnosis  indi- 
cates. Among  the  most  common  causes  of  hemorrhage  are  anemia, 
syphilis,  purpura,  tuberculosis,  and  a  generally  impaired  vitality,  rarely 
an  over-acting  heart ;  the  passive  hyperemia  attendant  upon  a  weak 
heart  is  a  potent  factor  requiring  a  course  of  preliminary  treatment. 

Specific  and  special  diseases  must  of  course  receive  the  treatment 
peculiar  to  these  conditions.  On  general  principles  the  following  tonics 
are  advisable  :  Quassia,  cinchona  and  its  alkaloids,  iron  in  its  various 
forms,  sulfuric  and  hydrochloric  acids,  arsenic,  pliosphorus,  nux  vomica 
and  its  alkaloid  strychnin.  With  these  general  tonics  various  hemo- 
statics can  be  given,  such  as  alum,  tannic  acid,  ergot,  erigeron  Cana- 
densis, and  gallic  acid.  Very  frequently  the  digestive  organs  require 
special  medication,  when  such  remedies  as  pepsin,  pancreatin,  hydro- 
chloric acid,  and  bismuth  subnitrate  are  indicated. 

The  following  prescriptions  have  proved  to  be  very  excellent  in 
their  special  province. 

As  general  tonics  : 


USE  OF  GENERAL  ANESTHETICS.  609 

I^.  Strychnise  suljjhatis, 

Acidi  arsenosi,  da.  gr.  j  ; 

Quinise  sulphatis,  gr.  xxx  ; 

Ferri  sulphatis  exsiccat.,  gr.  xv. 

M.  et  ft.  pilulse  No.  xxx. 

S.  One  immediately  after  each  meal. 

]^.  Elixir  ferri^  quinise  et  strychnise,  f|iv. 

S.  Teaspoonful  four  times  daily. 
To  improve  digestion  and  assimilation  : 

]^.  Acidi  hydrochlorici  diluti,  fgij  ; 

Ext.  ignatise  amaris  fld.,  fgj  ; 

Pepsin,  5iss ; 

Ext.  ipecacuanhse  fid.,  YTLiv  • 

Infusi  gentianse  comp.,  q.s.  ut  ft.  f^vj. — M. 

S.  Dessertspoonful  in  sherry  glass  of  water  immediately  after  meals. 
In  cases  of  undue  hemorrhage  after  extracting,  it  is  well  to  adminis- 
ter a  hemostatic  while  at  the  same  time  styptics  and  pressure  are  being 
applied  locally.     The  following  are  very  good  : 

;^.  Vin.  ergotae  (Squibb's),  f|iij. 

S.  Teaspoonful  every  two  hours. 

]^.  Ext.  ergotse  solidificat.,  .3J  ; 

Ext.  cannabis  indicse,  gr.  v ; 

Strychnise  sulphatis,  gr.  ss. 

M.  et  ft.  pilulffi  No.  xxx. 
S.  One  pill  three  times  a  day. 

Gallic  acid  and  aromatic  sulfuric  acid  may  be  administered. 

Digitalin  given  in  doses  of  Jg-  to  J  a  grain  three  or  four  times  daily 
for  a  series  of  weeks  will  often  effect  such  change  in  the  capillaries  as  to 
overcome  the  hemorrhagic  tendency.  This  has  been  repeatedly  and  suc- 
cessfully accomplished  in  epistaxis,  and  as  the  conditions  are  analogous 
it  can  be  employed  in  this  diathesis  with  expectation  of  similar  results. 

Extraction  under  the  Influence  op  Gtenbral  Anesthetics. 
While  it  is  undoubtedly  true  that  the  extraction  of  teeth  under  the 
influence  of  a  general  anesthetic  is  in  accordance  with  the  general  spirit 
of  the  age  which  seeks  to  spare  all  suffering  or  cause  the  infliction  of 
but  slight  pain,  yet  many  evils  attend  such  general  and  too  often 
indiscriminate  use.  "A  patient  under  the  effect  of  so  powerful  a 
drug  that  consciousness  is  destroyed  is  nearer  death  than  an  ordinary 
human  being,  since   the  primary  depressive   influence   upon  the   high 


39 


610  EXTRACTION  OF  TEETH. 

nervous  centres   may  speedily  pass   to  tlic   lower   vital   centres   in   the 
medulla  oblongata."  ' 

The  indiseriminate  use  of  general  anesthetics,  beside  their  possible 
danger  to  life  and  health,  has  an  accompanying  evil  in  the  demand 
for  the  extraction  of  teeth  which  are  salvable  and  useful,  but  which 
a  patient  insists  upon  having  removed  in  order  to  avoid  the  discom- 
fort attendant  upon  their  treatment  and  tilling.  No  one  questions 
or  denies  the  enormous  benefit  of  general  anesthetics  in  dentistry, 
particularlv  when  painful  oj)erations  are  to  be  performed  upon  ner- 
vous women  and  children,  but  if  the  patient  be  willing  to  sutfer  a  little 
pain  it  is  generally  better  to  extract  without  a  general  anesthetic,  as  in 
that  case  the  patient  can  assist  the  operator  by  keeping  the  head  in 
a  desired  position  with  the  mouth  and  lips  well  open,  and  in  various 
other  ways,  while  under  the  influence  of  an  anesthetic  the  muscles 
supporting  the  head,  jaws,  and  cheeks  are  so  relaxed  that  it  is  difficult 
to  keep  the  mouth  and  lips  well  open. 

If  the  operation  is  to  extract  a  ditficult  tooth,  the  operator  is  limited 
to  the  time  when  the  patient  is  under  the  influence  of  an  anesthetic,  and 
in  the  case  of  nitrous  oxid  the  time  is  very  short ;  but  without  an  anes- 
thetic there  is  not  this  limitation  as  to  time,  and  the  extraction  may  be 
done  with  that  care  and  deliberation  essential  to  a  proper  operation.  It 
is  an  inn)ortant  rule  in  any  branch  of  surgery  that  the  time  recpnred  to 
do  an  operation  must  be  sufficient  to  do  it  properly  and  without  un- 
necessary injury  to  the  adjoining  tissues. 

Examination  of  a  Patient  before  the  Administration  of  a  Gen- 
eral Anesthetic. — The  physical  examination  should  be  made  in  such  a 
way  that  it  will  not  cause  alarm  to  the  patient.  The  result  of  this  ex- 
amination governs  the  selection  of  the  anesthetic,  and  to  gome  extent 
shows  how  far  the  patient  should  be  carried  under  its  influence.  It  has 
been  said  that  a  greater  amount  of  care  should  be  used  if  the  patient  has 
or  is  suspected  of  having  organic  or  functional  disease  of  either  the  heart 
or  the  lungs.  This  is  quite  true  ;  but  at  the  same  time  the  greatest  amount 
of  care  should  be  observed  in  all  cases.  For  the  physiological  action  of 
various  anesthetics  the  student  is  referred  to  special  works  on  this  subject. 

The  question  often  arises  whether  anesthetics  should  be  used  at  all 
if  the  patient  has  either  organic  or  fuuetioual  disorder  of  the  heart. 
That  depends  to  a  large  degree  on  other  conditions  of  the  patient.  If 
the  shock  of  extraction  will  be  less  under  ether  or  nitrous  oxid,  then  by 
all  means  give  the  anesthetic  and  carry  the  patient  fairly  well  under  its 
influence,  so  that  there  will  be  neither  pain  nor  knowledge  of  the  ope- 
ration. Occasionally  patients  suifering  from  heart  disorders  can  bear 
a  certain  amount  of  pain  without  shock  ;  in  such  cases  it  is  better,  if 
the  operation  be  a  simple  one,  to  extract  while  in  the  normal  condition. 
^  H.  A.  Hare,  Park's  Text-Book  of  Surrjery,  vol.  li. 


USE  OF  GENERAL  ANESTHETICS. 


611 


Fig.  557. 


The  use  of  ether  for  extracting  has  certain  advantages.  If  for  any 
reason  the  operation  requires  longer  time  for  its  performance  than  the 
influence  of  the  nitrous  oxid  will  last — say  from  one  to  two  minutes 
— it  is  better  to  use  ether.  Ether  can  be  given  after  the  patient  has 
become  anesthetized  by  nitrous  oxid  and  oxygen  and  he  may  be  kept  un- 
der its  influence  for  a  considerable  time  ;  in  this  way  the  struggling  stage 
of  ether  is  avoided.  When  the  teeth  are  to  be  extracted  at  the  patient's 
home  or  at  any  other  place  outside  of  the  ofiice,  ether  is  more  conve- 
niently carried  than  nitrous  oxid.  If  properly  used  and  the  patient  has 
perfect  confidence  in  the  operator,  it  can  be  so  administered  that  one, 
two,  or  three  teeth  may  be  extracted  during  what  is  known  as  the  first 

stage  of  ether  anesthesia,  before  complete 
unconsciousness  and  long  before  the  strug- 
gling stage  commences. 

The  best  way  to  accomplish  this    is  to 
administer  the  ether  in  a  cone  made  by  a 
napkin  or  towel,  Avith  the  small  end  slightly 
opened  so  as  to  allow  the  patient  to  inhale 
a  small  quantity  of  air ;  it  also  permits  the 
patient  to  exhale  freely  and  with  a  less  suf- 
focating effect.     It  is  w^ll  to  place  in  the 
cone  a  small  soft  sponge  that  has  been  well 
washed  with  hot  water.     After  the  cone  is 
ready  the  patient    should  be    instructed   to 
breathe  several  long  and  full  inhalations ;  this 
clears  the  lungs  of  much  impure  air  and  ac- 
customs the  patient   to  the 
kind  of  breathing  required. 
Then  the  appliance  is  placed 
in  front  of  and  some  distance 
from  and  above  the  mouth 
and  nose,  being  careful  to 
allow  none  of  the  ether  to 
drop  from  the  cone  upon  the 
face,  as  it  will  demoralize  the 
patient.    The  inhaler  is  to  be 
advanced   toward   the   face 
slowly  and  gradually,  watch- 
ing the  effect  upon  the  pa- 
tient ;  if  there  is  a  tendency 
to  cough,  the  advance  should 
Nitrous  oxid  gasometer.  ^^  interrupted  Until  this  has 

passed.     After  the  cone  has  closed  tightly  over  the  mouth  and  nose, 
it  is  a  good  plan  to  ask  the  patient  to  hold  up  the  left  hand  as  long 


612 


EXTRACTION   OF   TEETH. 


as  possible ;  this  will  concentrate  his  thoughts  upon  the  act  and  away 
from  the  operation.  When  the  hand  begins  to  fall,  tlie  re(piest  to  raise 
the  hand  should  be  repeated  ;  it  will  soon  fall,  and  in  a  few  seconds 
afterward  one,  two,  or  three  teeth  may  be  removed,  the  number  de- 
pending entirely  upon  their  position  and  the  difficulty  to  be  overcome 
in  their  extraction.  As  soon  as  the  teeth  are  extracted  the  head  of 
the  patient  shouUl  be  raised  from  the  head-rest  and  the  body  carried 
forward,  and,  having;  a   hand  cuspidor  in  front,  the  patient  should  be 


Fig.  558. 


To  gas  cylinder 


Sectional  view  of  gasometer. 


requested  to  eject  the  blood  from  tlie  moutli  ;  thi.<  direction  is  usually 
complied  with.  The  patient  in  most  instances  recovers  in  a  few 
moments  and  with  no  disa<jreeable  after-effects,  but  if  the  ether  is 
carried    beyond    the    struggling    stage  to    the  point   of  complete  sur- 


USE  OF  GENERAL  ANESTHETICS.  613 

gioal  narcosis  the  nauseating  after-effects  are  very  disagreeable  unless 
the  patient  has  been  thoroughly  prepared  for  the  occasion. 

Nitrous  oxid  is  the  anesthetic  most  commonly  administered  for  the 
extraction  of  teeth,  and  under  ordinary  circumstances  is  the  best  Until 
lately  every  operator  was  his  own  maker  of  the  gas— this  was  a  great 
disadvantage-but  now  it  can  be  procured  in  a  liquefied  form  com- 

FiG.  559. 


Nitrous  oxid  inhaler. 

pressed  in  cylinders.     There  are  many  different  appliances  used   for 


614 


EXTRACTIOS  OF  TEETH. 


tlic  administering  of  this  gas  even  wlion  nsing  it  in  a  condensed  form. 
One  of  the  raost  jironiinent  is  that  sliown  in  Figs.  557  and  558,  in 
whicli  the  gas  is  (h-awn  into  a  reservoir  and  then  passes  through  a  flex- 
ible tube  to  the  mouth-piece  (Figs.  559  and  560). 

Fio.  560. 


Hood  inhaler. 


The  two  principal  mouth-pieces  are  Fig.  559,  which  should  have 
the  detachable  lip-shield  removed  so  that  the  tube  may  be  placed 
directly  into  the  mouth  and  the  lips  compressed  around  the  tube  by 
the    operator,  at    the    same    time    closing    the    nostril    by    the    thumb 


USE  OF  GENERAL  ANESTHETICS. 


615 


Fig.  561. 


Stand  for  compressed  gas  cylinder,  gas  bag,  tube,  and  inhaler. 


<)!() 


EXTRACTION  OF  TEETH. 


and  Hngor,  and  Fig.  560,  wliicli  is  UudWii  as  a  liood  inlialer;  it  is 
made  to  cover  the  nose  as  well  as  tiic  Dioiith.  The  advantage  of  the 
first  niouth-piece  is  that  the  li|)s  may  ho  (dosely  watched  for  the  change 
(•f  eoh)r  (U'lioting  oxygen-starvation  of  the  bh)od,  Mhicli  tiie  experienced 
operator  combats  by  admitting  a  certain  amount  of  air  witli  the  gas  as 
required.  Fig.  562  represents  a  portalilc  appliance  to  be  used  at  a 
patient's  home  or  away  from  tlie   regular  otlicc. 

Fig.  562. 


Portable  nitrous  oxid  apparatus. 


Dr.  Hewitt's  Method. — Dr.  Frederick  Hewitt  of  London,  England, 
has  devised  the  apparatus  shown  in  Figs.  563  and  564.  The  three 
cylinders  contain  the  compressed  gas,  two  being  filled  with  nitrous  oxid 
ami  one  with  oxygen.  The  valves  of  the  cylinders  are  opened  by  a  key 
which  is  controlled  by  the  foot  of  the  operator.  The  tube  passing  from 
the  cylinders  to  the  receiving-bag  is  double,  a  smaller  tube  being  placed 
within  the  outer  larger  tube.  The  receiving-bag  is  also  double,  being 
divided  by  a  rubber  septum  into  two  compartments  Avhich  have  their 
outlet  in  the  double  tube  which  leads  to  the  inhaler.  To  the  receiving- 
bag  is  attached  a  mixing-chamber,  and  to  this  the  inhaling-tube  or  hood 
is  fastened.  This  appliance  is  used  very  successfully  in  England  and 
has  been  introduced  into  the  United  States.  It  has  proved  satisfactory 
to  all  who  have  tried  it.  The  bags  and  tubing  should  be  made  of 
more  durable  material  when  intended  for  use  in  the  American  climate. 


USE  OF  GENERAL  ANESTHETICS. 


617 


The  manner  in  which  the  appliance  is  used  is  as  follows  :  The  valves 
in  the  mixing-chamber  (Fig.  564)  are  closed,  then  oxygen  is  let  into  its 
compartment  of  the  receiving-bag  until  the  latter  is  nearly  filled,  when 
the  nitrous  oxid  is  admitted  into  its  compartment.  The  patient  being 
prepared,  the  inhaling-tube  or  hood  is  placed  in  position,  and  the 
patient  is  directed  to  breathe — long,  full,  and  steadily.  If  the  tube  is 
used  it  is  necessary  to  close  the  nose  by  the  thumb  and  finger. 


Fig.  563. 


Complete  apparatus  of  Dr.  Hewitt  for  admiuistering  mixed  nitrous  oxid  and  oxygen. 

The  valves  are  not  changed  for  a  few  inhalations,  during  which  time 
only  air  is  inhaled ;  then,  pressing  the  indicator  a  downward  to  the  first 
notch  b,  the  air  is  cut  oif,  and  the  patient  receives  pure  nitrous  oxid ; 
this  is  allowed  for  a  few  more  inhalations,  and  then  the  indicator  is  car- 
ried to  the  next  notch  and  one  part  of  oxygen  is  alloAved  to  pass  into 
the  respiration.  When  the  indicator  is  carried  to  the  third  notch  two 
parts  are  received  by  the  patient,  and  so  on  until  the  maximum  amount 
of  oxygen  required  by  the  patient  has  been  reached. 

It  has  been  found  by  careful  study  of  many  thousands  of  cases  and 
by  special  scientific  investigation  that  the  asphyxial  condition  incident 
to  most  cases  of  nitrous  oxid  inhalation  is  quite  unnecessary  to  the  pro- 


618 


EXTRACTION  OF  TEETH. 


duotion  of  nitroui*  oxid  anesthesia.  It  is  also  justly  considered  to  he 
suhjeetiiig  a  patient  to  an  unwarrantable  danger  to  ])ernut  the  asphyxial 
etfeet  to  manifest  itself  to  a  ]>rofound  degree,  as  in  manv  eases  it  is 
a  menace  to  life  and  health,  and  might  have  a  fatal  ctl'cct.  The  object 
(if  J)r.  Hewitt's  mi'thod  is  to  ccintrol  or  eliminate  the  as})hyxial  element 
by  administering  a  requisite  amount  of  oxygen. 

Fig.  564. 


Showing  arrangement  of  the  mixing-chamber,  with  dial  and  valve  for  controlling  the 
relative  proportions  of  the  gases. 

No  fixed  rule  can  be  laid  down  for  the  quantity  of  oxygen  to  be 
added,  as  each  case  will  require  a  different  amount  and  this  amount 
varies  during  the  several  stages  of  the  anesthetic  procedure.  The 
operator  is  guided  entirely  by  the  symptcmis  of  the  ])atient  during  the 
administration,  his  object  being  to  avoid  on  the  one  hand  the  tendency 
toward  asphyxia  indicated  by  cyanosis  of  the  lips,  and  return  of  con- 
sciousness and  sensation  on  the  other  hand,  ^vhich  is  easily  produced 
by  an  excess  of  oxygen.  By  the  admixture  of  oxygen,  as  in  Dr. 
Hewitt's  method,  the  anesthesia  is  somewhat  prolonged  over  the  ordinary 
nitrous  oxid  method  and  is  slower  of  induction,  but  there  is  entire 
absence  of  cyanosis,  stertorous  breathing,  jactitation,  or  any  of  the 
symptoms  of  asphyxia.  The  modification  of  the  Hewitt  apparatus 
that  has  been  lately  introduced  embodies  certain  features  that  make  it 
an  improvement  on  the  original  ai)})aratus.  The  arrangement  of  the 
mixing-chamber  in  reference  to  the  bags  containing  the  gases  is  such  as 
to  enable  the  operator  to  more  accuratel^^  control  the  mixture  that  is 


USE  OF  GENERAL  ANESTHETICS. 
Fig.  565. 


619 


Apparatus  for  administering  nitrous  oxid  and  oxygen  combined :  a,  key  to  oxygen  bag ;  6,  key  to 
oxygen  cylinder;  c,  gauge  showing  percentage  of  oxyaren  being  administered,  d,  mixing- 
chamber;  e,  e,  keys  to  nitrous  oxid  cylinders;  /,  key  lo  nitrous  oxid  bag. 


620  EXTRACTIOX   OF  TEETH. 

adniinistorod  to  the  pationt.  lly  :i  turn  of  tho  havers  a  ;in(l/(Fig.  5G5) 
any  gradation  of"  the  gases  may  he  ohtaiiied,  tVoin  pure  nitrous  oxid  on 
the  one  hand  to  pure  oxygen  on  the  other.  Tlie  construction  of"  the 
apparatus  is  such  as  to  better  witlistand  the  climatic  conditions  than  the 
Hewitt  apparatus.  A  brief  description  will  suffice  to  sliow  the  working 
of  the  apparatus. 

There  are  three  cylinders,  two  containing  compressed  nitrous  oxid,  and 
the  other  compressed  oxygen. 

Two  bags,  one  of  black  material  to  contain  the  nitrous  oxid,  the  other 
of  red  material  to  contain  the  oxygen. 

The  key  to  each  cylinder  (see  b  and  e,  c)  opens  the  valve  and  allows 
the  gas  to  pass  into  its  respective  bag. 

By  opening  the  valve  (see  /)  of  the  nitrous  oxid  bag  the  gas  passes 
into  the  mixing-chamber,  from  which  it  flows  through  the  covered  rub- 
ber tube  to  the  inhaler. 

When  it  is  desired  to  combine  oxygen  with  nitrous  oxid,  open 
gauged  valve  (see  a,  c)  to  the  oxygen  bag  ;  this  will  admit  the  oxygen 
into  the  mixing-chamber.  Both  gases  will  pass  through  the  tube  to 
the  inhaler. 

The  proportion  of  oxygen  used  will  be  determined  by  the  degree 
to  which  the  gauged   valve  is  opened. 

By  closing  the  valve  of  the  nitrous  oxid  bag,  oxygen  can  be  given 
separately. 

Similar  results  arc  obtained  when  air  is  admitted,  instead  of  oxygen, 
to  the  patient  during  the  nitrous  oxid  administration.  The  details  of 
this  procedure  are  set  forth  in  the  following  chapter. 


CHAPTER    XXI.   (Continued). 

EXTRACTION  OF  TEETH  UNDER  NITROUS  OXID 
ANESTHESIA. 

By  J.  D.  Thomas,  D.  D.  S. 


Where  the  operation  would  cause  excessive  pain,  the  extraction  of 
a  tooth  without  the  aid  of  an  anesthetic  is  to-day  little  short  of  bar- 
barous. It  is  cruel  to  the  patient,  and  if  the  subject  be  a  child, 
wantonly  so.  Very  few  people  can  submit  to  the  operation  without 
more  or  less  physical  resistance,  and  even  though  this  be  involuntary 
no  operator  can  do  full  justice  in  such  a  case,  no  matter  how  skillful  he 
may  be.  Such  resistance  causes  more  or  less  unnecessary  strain  to  be 
applied  in  one  direction  or  another  against  the  process,  which  results  in 
increased  inflammation  as  a  sequence.  Besides,  as  a  rule  the  liability 
of  breaking  the  tooth  or  portions  of  the  alveolar  plate  or  other  accidents 
is  increased  a  hundredfold. 

Nitrous  oxid  is  in  all  respects  the  very  best  anesthetic  for  the  pur- 
poses of  the  dentist.  Properly  used,  it  is  almost  entirely  free  from 
danger  and  is  rarely  productive  of  nausea  or  depression  as  an  after- 
effect, even  temporarily.  It  seldom  requires  over  sixty  seconds  to  pro- 
duce anesthesia,  and  in  less  than  that  period  of  time  the  patient  is 
fully  recovered,  with  no  knowledge  of  the  operation,  and  is  ready  to 
depart  as  soon  as  bleeding  ceases.  To  accomplish  such  a  result,  of 
course,  requires  experience  and  some  degree  of  dexterity,  but  the  con- 
ditions are  such  that  any  dentist  with  a  fair  amount  of  experience  can 
operate  successfully  with  it  for  the  removal  of  from  one  to  four  or  five 
teeth,  and  perhaps  more — the  main  essential  in  operating  by  the  aid  of 
nitrous  oxid  being  to  utilize  every  second  of  time  during  the  period  of 
anesthesia,  and  not  to  waste  it  in  hunting  forceps  or  deciding  how  they 
should  be  used. 

The  best  success  is  obtained  by  formulating  a  system  of  working  by 
which  one  can  accomplish  the  most  in  the  shortest  space  of  time.  The 
operating  period  seldom  extends  over  forty-five  seconds  and  often  less, 
so  that  every  second  wasted  in  any  way  whatever  is  so  much  time  lost, 
and  success  is  diminished  to  just  that  extent. 

Nitrous  oxid  must  be  absolutely  pure,  and  if  be  kept  over  water  it 

621 


622  EXTRACTION   OF  TEETH    I'XDER   XITROUS  OXTD. 

must  be  fresh.  In  former  times  when  the  dentist  manufaetured  his  own 
gix:^,  to  insure  perfect  purity  it  was  necessary  to  test  the  ammonia  nitrate 
before  using  it  for  making  the  nitrous  ox  id,  but  at  the  present  day  the 
pure  gas  is  made  with  great  accuracy  by  the  manufacturers  and  is 
supplied  chemically  pure,  compressed  in  cylinders,  so  that  the  individ- 
ual dentist  is  relieved  of  tlie  responsibility  of  manufacturing  his  own 
gas  and  of  the  troubles  necessary  to  secure  purity. 

The  first  essential  to  success  in  its  administration  is  a  perfect 
INHALER.  This  should  be  sufficiently  large  to  permit  the  patient  to 
breathe  without  the  slightest  exertion.  Patients  are  always  in  a  more 
or  less  nervous  state  upon  approaching  the  dental  chair  for  extraction. 
There  is  usually  accelerated  heart-beat  and  consequently  deranged 
respiration,  and  unless  they  can  breathe  through  the  inhaler  with  per- 
fect freedom  they  labor  under  a  sense  of  suffi>cation  which  adds  greatly 
to  their  apprehension  and  disturbs  their  equanimity  while  passing  under 
the  influence  of  the  anesthetic. 

The  inhaler  shown  in  Fig.  560  is  perhaps  the  best  one  upon  the 
market,  but  has  the  disadvantage  of  having  hard  disk  valves,  and 
while  the  size  is  sufficiently  large  for  most  purposes  the  space  between 
the  outer  circumference  of  the  disk  and  the  inner  circle  of  the  pipe  is 
so  small  that  it  does  not  at  all  times  permit  of  free  ingress  of  the  gas 
to  the  lungs,  and,  besides,  such  valves  are  not  always  airtight. 

The  best  inhaler  is  one  made  of  vulcanized  rubber  turned  to  the 
proper  dimension  and  fitted  with  valves  made  of  rubber  dam  (Fig. 
566).     These  valves  have  the  property  of  fitting  closely,  making  the 

Fig.  566. 


Thimias's  inhaler. 


passages  airtight,  and  being  flexible  they  admit  the  gas  to  the  lungs 
with  little  or  no  obstruction.     This  inhaler  is   the  one  employed  by 


ADMINISTRATION  OF  NITROUS  OXID.  623 

most  operators  who  make  a  specialty  of  extraction,  and  is  made  only 
upon  special  order. 

In  giving  nitrous  oxid  it  is  necessary  that  the  valves  of  the  inhaler 
shall  be  airtight,  for  if  there  is  a  leakage  by  which  air  is  constantly 
being  admitted,  it  will  interfere  greatly  with  the  production  of  the 
desired  results.  The  hood  face-piece  should  never  be  used.  Aside  from 
the  impossibility  of  fitting  the  face  so  closely  as  to  preclude  the  admis- 
sion of  some  air  during  the  administration,  particularly  when  beard 
exists,  it  covers  the  lips  from  view,  and  these  are  an  important  index 
during  the  process  of  anesthesia ;  the  color  of  the  blood  as  shown 
through  the  mucous  membrane  of  the  lips  should  never  be  lost  to 
sight. 

There  is  no  separation  of  the  elements  of  nitrous  oxid  at  the  tem- 
perature of  the  human  body,  or  during  its  inhalation,  consequently  it 
is  practically  an  inert  gas  so  far  as  its  power  to  support  life  is  con- 
cerned. It  possesses  strong  anesthetic  properties  but  it  is  also  to  a 
degree  productive  of  asphyxia,  and  the  color  of  the  lips  must  be  ob- 
served as  a  guide  to  indicate  the  extent  to  which  asphyxia  is  taking 
place.  It  has  been  previously  said  that  the  valves  of  the  inhaler  must 
be  airtight,  for  a  constant  leakage  of  air  will  prevent  the  production 
of  complete  anesthesia,  and  yet  at  the  proper  time  during  the  inhala- 
tion the  admission  of  air,  controlled  by  opening  the  nose  or  raising  the 
lips,  is  not  only  desirable  but  essential  to  the  proper  and  successful  ex- 
hibition of  the  anesthetic. 

By  the  judicious  admission  of  air  at  the  proper  time  the  accompany- 
ing symptoms  of  approaching  asphyxia  are  obviated  and  perfect  anes- 
thesia is  secured  without  any  of  the  convulsive  muscular  twitching 
which  takes  place  when  the  pure  gas  is  given.  Dr.  Hewitt  of  London 
advocates  the  admixture  of  oxygen  with  nitrous  oxid,  for  which  he  has 
introduced  the  appliances  described  on  p.  617,  but  by  admitting  air  as 
here  suggested  similar  results  are  obtained  with  less  manipulation. 

The  use  of  props  to  keep  the  jaws  open  is  necessary  to  insure  success. 
They  give  free  scope  for  operating,  and  there  is  no  time  lost  in  prying 
the  mouth  open,  as  nearly  always  happens  when  props  are  not  used. 
Props  made  of  hard  wood  and  of  different  sizes  are  the  most  satisfactory ; 
they  should  have  strings  attached,  more  to  reassure  the  patient  than 
for  any  other  reason.  Unfortunately,  a  number  of  years  ago  a  patient 
died  as  a  result  of  getting  a  cork  in  the  larynx,  and  this  has  never  been 
forgotten.  Consequently  the  string  is  an  assurance  to  the  patient  that 
the  prop  cannot  slip  down  the  throat. 

The  ordinary  dental  chair  is  not  desirable  for  use  in  administering 
nitrous  oxid,  particularly  those  chairs  having  stationary  footstools  at- 
tached.   Patients  are  sometimes  restless,  and  every  motion  made  by  the 


624  EXTRACTIoy  OF  TEETH    UyDf:R  NITROUS  OXID. 

ivvt  upon  a  iixt'd  lbt)t.sti)ul  will  j)r()iliK-o  a  responsive  movement  of  the 
body,  thereby  increasing  the  risk  of  accident  to  the  part  being  operated 
upon.  A  detached  stool  upon  casters  is  easily  pushed  away,  so  that 
any  disposition  to  move  the  extremities  may  be  permitted  without 
art'eeting  the  stability  of  the  upper  part  of  the  body. 

This  apparent  resistance  on  the  part  of  the  patient  is  not  necessarily 
the  indication  of  a  knowledge  of  what  is  being  done  ;  the  upper  brain 
function  may  be  paralyzed  while  the  sensory  perij)herals  and  motor 
ganglia  are  not,  under  which  circumstances  the  patient  is  not  thoroughly 
anesthetized.  Resistance  may  take  ])lace  at  the  beginning  or  just  at  the 
termination  of  the  anesthetic  procedure,  and  if  the  operator  ceases  at 
once  the  j)atient  will  declare  absolute  unconsciousness  of  the  ()])eration. 
It  is,  however,  sometimes  permissible  to  oj)erate  during  the  stage  just 
noted  in  cases  where  the  systemic  conditions  are  such  that  it  would  be 
unwise  to  carry  the  patient  to  the  state  of  })rofouud  insensibility.  These 
are,  however,  exceptions  and  not  the  rule.  To  have  the  exhibition  per- 
fectly satisfactory  there  should  be  no  resistance  or  outcry. 

A  competent  ass^istant  is  necessary,  not  only  a^  a  protection  against 
charges  which  might  be  suggested  by  lascivious  dreams — as  has  occurred 
when  ether  has  been  employed  (though  the  period  of  insensibility  under 
nitrous  ox  id  is  so  short  that  it  would  seem  that  no  one,  however  evilly 
or  honestly  disposed,  could  ever  sustain  such  a  charge) — but  an  assist- 
ant can  render  much  aid  by  holding  the  tube,  lowering  or  raising  the 
head,  taking  care  that  the  operator  does  not  bruise  the  lips,  holding  the 
patient  if  restless,  particularly  the  hands,  and  waiting  upon  the  patient 
durinfir  recoverv  from  the  anesthetic. 

The  assistant  should  be  a  woman,  as  it  adds  very  materially  to  the 
comfort  of  female  patients  to  have  such  a  person  in  attendance. 

The  operator  should  receive  the  patient  in  such  a  manner  as  to 
inspire  entire  confidence.  If  necessary,  any  doubts  or  possibilities  of 
accident  should  be  clearly  explained  to  the  patient,  so  that  in  the  event 
of  untoward  results  there  will  not  be  a  humiliating  sense  of  fiiilure. 

The  patient  is  seated,  and  after  a  careful  examination  has  been  made 
and  the  condition  of  the  tooth  or  teeth  is  ascertained,  the  prop  is  placed 
where  it  will  l)c  least  in  the  way.  The  assistant  then  places  the  tube 
in  the  mouth  and  the  patient  is  directed  to  close  the  lips  and  breathe 
through  the  mouth  instead  of  the  nose  ;  in  the  meantime  closing  the 
nostrils  with  the  third  finger  and  thumb  of  the  left  hand,  the  first  and 
second  pressing  the  upjier  lip  al)out  the  mouthpiece,  while  the  thumb 
and  fingers  of  the  right  hand  support  the  lower  lip. 

While  inhaling  the  gas  it  is  desirable  that  patients  should  breathe 
as  in  ordinary  res])iration,  for  two  reasons  :  First,  if  instructed  to  take 
long  and   deep  breaths    they  exert  themselves   beyond    their   natural 


THE  OPERATION  OF  EXTRACTION.  625 

rhythm,  and  with  unconsciousness  comes  involuntary  suspension  for  some 
seconds,  and  should  it  occur  in  one  who  becomes  quickly  asphyxiated 
the  few  seconds  of  suspension  are  sufficient  to  produce  alarming  symp- 
toms which  will  require  some  effi^rt  to  counteract.  Second,  if  the 
patient  breathe  slower  or  less  deeply  than  is  natural  there  is  a  sense 
of  suffocation  produced  which  grows  in  intensity  until  unconscious- 
ness supervenes,  when  the  lungs  and  diaphragm  will  exert  their  func- 
tion, producing  violent  respiratory  effort  which  will  be  followed  by 
marked  exhaustion  upon  recovery.  None  of  these  effects  need  be 
produced  if  the  operator  have  complete  control  of  the  situation. 

No  one  can  explain  the  symptoms  of  approaching  and  complete 
anesthesia  in  such  a  manner  as  will  inform  a  novice  sufficiently  well  to 
undertake  the  responsibility  of  administering  the  gas ;  these  can  only  be 
learned  through  observation  and  experience,  but  the  first  prominent 
indication  will  be  a  discoloring  of  the  lips  and  subsequent  pallor  of 
countenance,  which  is  not,  however,  an  indication  of  cardiac  depres- 
sion, but  is  due  to  the  blood  color  shown  through  the  skin.  Should 
the  patient  be  of  the  blonde  and  florid  type  this  appearance  will  be 
more  marked,  and  it  is  here  that  the  admission  of  a  small  amount 
of  air  is  called  for,  particularly  if  the  blueness  seems  to  approach 
more  rapidly  than  the  anesthesia. 

If  the  pure  gas  is  given  to  complete  narcosis,  there  will  be  twitching 
of  the  muscles  of  the  neck  and  wrists.  Stertor  and  irregular  breathing 
and  sometimes  decided  convulsive  action  occur,  which  to  one  inexperi- 
enced becomes  distressing,  if  not  alarming,  to  behold. 

All  these  symptoms  are  at  once  relieved  by  air-breathing,  and  if 
there  is  a  judicious  admission  of  air  during  the  administration  of  the 
anesthetic  they  will  be  avoided  entirely. 

The  patient  being  anesthetized — and  the  instruments  being  always  in 
place  so  that  there  will  be  no  delay  in  picking  up  the  pair  of  forceps 
required,  so  that  every  second  of  time  may  be  utilized  by  the  work 
in  hand — the  next  step  is  the  extraction. 

The  Operation  of  Extraction. — The  proper  way  to  perform  the 
operation  is  to  stand  in  one  position,  at  the  right  side  of  the  patient, 
during  the  whole  proceeding.  For  extracting  with  the  greatest  facility 
the  operator  should  assume  such  a  position  that  in  standing  erect  the 
patient's  head  will  be  about  opposite  his  upper  waistcoat  pocket.  To 
do  this  a  pair  of  stools  should  be  used,  one  just  back  of  the  chair  and 
one  by  the  side  which  may  be  easily  pushed  aside  when  not  needed. 
While  administering,  the  operator  can  stand  upon  the  floor,  and  ascend 
the  stool  just  before  the  time  for  operating.  This  position  is  assumed 
by  the  most  successful  operating  specialists,  and  is  adopted  as  the  result 

40 


626  EXTRACTION  OF  TEETH   UNDER  NITROUS  OXID. 

of  long  exporienoo  and  dictated  by  the  desin^  to  hrinj;  abont  a  position 
for  work  wliicli  jx'nnits  of  its  most  rapid  pcrrnrmancc  and  at  the  same 
time  enables  the  o]ierator  to  l)ring  to  Ix-ar  tlie  greatest  amount  of  foree 
with  the  least  physical  exertion. 

When  extracting,  for  example,  a  lower  tooth,  and  it  is  necessary  to 
force  the  beaks  of  the  forceps  well  down  through  the  process,  the 
instrument  is  manipulated  by  the  hand  and  wrist  with  the  arm  held 
closely  to  the  body  to  steady  it.  The  weight  of  the  body  is  allowed  to 
descend  to  the  proper  degree  by  bending  the  knees,  and  when  the  for- 
ceps are  fixed,  should  force  for  pulling  be  re(|uired,  the  straightening  of 
the  knees  will  raise  the  body,  the  arm  being  held  firmly  as  described. 
The  hand  will  be  used  exclusively  for  manipulating  and  guiding,  wiiile 
the  force  will  be  supplied  by  straightening  the  knees  much  the  same  as 
is  applied  in  lifting  weight  from  the  ground.  Of  course,  to  become 
expert  one  must  have  all  of  his  limbs  equally  trained. 

In  operating  on  the  upi)er  jaw  the  method  is  much  the  same,  onlv 
reversed,  bending  the  knees  first  to  lower  the  body  and  forcing  the 
instrument  to  position  by  straightening  and  throwing  as  much  of  the 
bodily  weight  upon  the  arm,  by  bending  the  knees,  as  is  necessary  for 
pulling.  By  so  doing  a  tooth  will  never  be  allowed  to  leave  the  socket 
suddenly  as  by  a  jerk,  for  the  operator  has  perfect  control  of  his  hand 
and  wrist,  and  the  danger  of  bruising  the  opposite  teeth  in  either  jaw  by 
the  forceps  is  avoided. 

The  Forceps. — Seven  pairs  of  forceps  are  all  that  are  nsed  by  the 
writer  for  extraction  in  ordinary  cases.  For  the  uj^per  teeth,  a  right  and 
left  pair  for  the  molars,  a  bayonet-shajied  instrument  with  the  outer  beak 
pointed  to  fit  between  the  buccal  roots,  and  both  beaks  serrated.  In 
working  upon  both  sides  of  the  mouth  a  ))air  without  pointed  beaks  may 
be  used  with  advantage  to  avoid  changing.  One  alveolar  pair  suffices 
for  the  roots  of  all  molars  and  bicuspids  on  either  side.  These  are 
made  bayonet-shaped  with  smooth  concave  beaks,  but  having  well 
sharpened  edges.  The  pair  for  the  incisors  is  straight,  with  beaks  simi- 
lar to  the  alveolar  pair,  and  when  extracting,  say  all  the  upper  teeth, 
can  be  used  upon  all  ten  front  ones  with  equal  facility. 

For  teeth  in  the  lower  jaw  the  molar  pair  is  made  with  both  beaks 
pointed,  serrated,  and  gracefully  curved  so  as  to  bring  the  force  as  nearly 
direct  as  possible;  these  are  efjually  api)licable  for  all  the  molars  on 
either  side  and  are  shaped  the  same  as  the  alveolar  pair.  The  alveolar 
pair  are  shaped  the  same  as  those  for  the  molars,  have  smooth  concave 
beaks  with  sharp  edges,  and  are  used  fitr  all  molar  roots  and  bicuspids 
(Fig.  567).  The  pair  for  front  teeth  is  curved  under  the  handle  and 
may  have  serrated  beaks,  as  the  roots  of  the  lower  centrals  and  laterals 


THE  OPERATION  OF  EXTRACTION. 


627 


Fig.  567. 


Ml 


h'  w 


Alveolar  forceps. 


are  so  flat  that  a  sharp  beak  is  apt  to  cut 
them  oif,  if  too  much  grasp  is  applied. 
They  seldom  require  the  force  necessary 
in  the  extraction  of  other  teeth. 

The  writer  prefers  forceps  that  are  not 
nickel-plated,  as  this  imparts  a  slippery 
or  "greasy  "  feeling  to  the  handle,  making 
the  hold  less  secure,  which  induces  an 
increase  of  force  in  the  operator's  grasp,  with 
greater  liability  of  cutting  or  crushing  the  teeth. 
With  forceps  having  beaks  that  are  not  serrated, 
teeth  having  conical  tapering  roots  will  prevent 
the  perfect  fitting  of  the  cutting  edge  ;  these  will 
sometimes  slip  through  the  posterior  opening  of 
the  upper  or  lower  alveolar  pairs  with  great  force. 
The  writer  has  seen,  in  one  instance,  a  tooth  slip 
through  the  beaks  of  an  unserrated  pair  of  for- 
ceps and  break  a  pane  of  glass  in  front  of  the 
chair,  and  an  under  single  molar  root  which 
shot  up  with  sufficient  velocity  to  penetrate  the 
soft  palate. 

In  extracting,  particularly  under  nitrous 
oxid,  no  instrument  should  be  used  which  will 
not  securely  retain  any  tooth  or  root  until  it  is 
safely  placed  outside  the  mouth. 

Elevators  are  wholly  out  of  place  when  work- 
ing under  an  anesthetic.    They  permit  no  control 
of  the  root  or  tooth  whatever,  and  the  liability 
of  a  tooth  slipping  into  the  throat  under  such 
circumstances  is  too  great  to  warrant  the  risk. 
The  art  or  "  knack  "  of  extract- 
ing does  not  consist  of  giving  a 
rotary   motion    to    one    kind    of 
tooth  and  a  lateral  or  "  in-and-out 
motion  "  to  another,  but  rather  of 
"  working  "  the  tooth  in  the  socket 
without   any   pulling   until    it   is 
started  or  loosened   from  its    at- 
tachment, when  the  pulling  force 
may  be  applied,  and  to  do  this  the 
forceps    must   be   placed    upon   a 
tooth  so  nicely  that  the  tooth  and 
instrument  will  feel  to  the  hand 


628  EXTRACTION  OF  TEETH  UNDER  NITROUS  OX  ID. 

as  one  continuous  object,  so  that  tlie  slightest  motion  in  any  direction 
will  have  immediate  effect  in  "starting"  the  tooth.  The  operation  is 
completed  by  continued  working  while  the  pulling  is  applied  in  the 
direction  which  will  prove  the  most  effective  in  dislodgment. 

This  "  working"  should  be  done  with  as  little  motion  as  is  possible, 
for  the  smallest  degree  of  straining  upon  the  process  laterally  only 
adds  so  much  more  distention  to  the  alveolar  plates,  and  increases  the 
inflammation  and  pain  after  the  operation.  When  nitrous  oxid  was 
first  introduced  and  extracting  was  transferred  to  those  who  made  it  a 
specialty,  it  was  noticed  that  there  was  less  soreness  of  the  mouth  follow- 
ing the  operation,  and  it  was  thought  by  some  that  the  oxygen  of  the 
gas  produced  a  beneficial  effect  upon  the  blood  which  caused  better 
healing,  but  such  is  not  the  case. 

The  object,  in  extracting,  of  one  who  becomes  expert  by  constant 
practice  is  to  save  the  surrounding  parts  from  all  unnecessary  strain, 
consequently  less  pain  and  soreness  follows  the  operation.  There  are 
teeth  having  curved  and  divergent  roots,  and  cases  of  exostosis,  which 
will  require  great  effort  to  remove,  but  even  in  these  the  position  as- 
sumed and  the  process  of  "  working "  the  tooth  in  the  direction  of 
the  force  applied  all  tend  to  accomplish  the  result  with  less  injury  than 
would  be  otherwise  produced. 

In  this  way  the  breaking  of  a  tooth  need  seldom  occur  unless  inten- 
tionally. If  in  extracting  an  upper  or  lower  molar  one  finds  by  the 
extra  amount  of  force  required  that  it  will  not  readily  yield,  then  it  is 
better  to  break  the  crown  off  and  with  the  sharp  alveolar  forceps  remove 
the  roots  separately.  This  can  be  done  with  less  injury  to  the  alveolar 
plates  than  if  much  greater  force  were  applied  to  remove  the  tooth 
as  a  whole. 

There  will  be  cases  of  fracture  of  points  of  roots  which  are  much 
curved  or  divergent,  but  many  of  these  retained  fragments  may  be  per- 
mitted to  remain  until  in  the  process  of  exfoliation  they  come  to  the 
surface  if  their  retention  is  regarded  as  likely  to  give  rise  to  less 
trouble  than  the  injury  incident  to  their  removal  would  cause.  But 
these  need  rarely  occur  if  the  operator  has  by  experience  acquired  that 
sense  of  feeling  which  tells  him  at  once  the  direction  of  the  curve  or 
the  size  of  the  exostosis. 

Inverted  or  impacted  third  molars  arc  the  most  difficult  cases  which 
present  themselves  for  extraction.  Instead  of  being  surrounded  by 
pliable  process  they  are  planted  in  compact  bone  at  the  angle  of  the 
jaw,  bound  in  by  the  second  molar  in  front  and  hard  bone  on  the 
buccal  side,  so  that  above  it  in  the  angle  is  the  only  direction  offered 
for  removal,  workiug  them  toward  the  tongue  where  the  bone  is 
thinnest. 


THE   OPERATION  OF  EXTRACTION.  629 

In  addition  to  the  difficulty  in  removing  these  teeth,  this  severe 
process  of  pressing  the  inner  alveolar  plate  toward  the  tongue  excites 
a  state  of  inflammation,  easily  communicated  to  the  soft  tissues  of  the 
throat,  and  the  after-effects  assume  in  many  cases  such  serious  condi- 
tions that  it  is  better  practice  to  remove  the  second  molar. 

If  the  third  molar  is  sound  it  may  remain  and  will  cause  no  further 
trouble,  as  the  primary  difficulty  was  caused  by  crowding  and  pressing 
upon  the  second  molar ;  and  should  it  be  necessary,  from  decay,  to  re- 
move it,  the  extraction  of  the  second  molar  first,  renders  the  operation 
simple  and  easy  of  accomplishment. 


CHAPTER   XXI.    (Concluded). 

LOCAL  ANESTHETICS  AND    TOOTH    EXTRACTION. 

By  Henry  H.  Buechard,  M.  D.,  D.  D.  S. 


Prior  to  the  discovery  and  application  of  cocain,  the  local  anes- 
thetics employed  to  produce  a  condition  of  analgesia  of  the  structures 
surrounding  a  tooth  to  be  extracted  were  sprays  of  extremely  volatile 
substances.  Through  the  rapid  evaporation  of  a  spray  of  one  of  the 
lighter  hydrocarbons,  a  condition  of  refrigeration  of  tissues  was  brought 
about  during  which  a  tooth  could  be  extracted  painlessly.  Sprays  of 
rhigolene  and  of  ethylic  ether  have  been  superseded  by  those  of  ethyl 
and  of  methyl  chlorid,  these  substances  being  more  volatile ;  directed 
in  a  fine  spray  over  the  gum  of  the  tooth  to  be  extracted,  an  intense 
local  anemia  is  produced,  and  as  a  consequence  analgesia  results.  If 
the  refrigeration  be  rapidly  produced  and  the  operation  be  performed 
promptly  upon  the  attaining  of  analgesia,  the  frozen  tissues  recover 
with  but  sliffht  reaction.  It  is  to  be  remembered  that  the  tissues  are 
frozen,  and  if  the  action  be  prolonged  a  condition  akin  to  chilblain  is 
present.  The  mode  of  application  is  as  follows :  All  of  the  mucous 
membrane,  except  that  over  the  roots  of  the  doomed  tooth,  is  to  be  pro- 
tected from  the  spray  by  means  of  napkins.  The  spray  is  directed 
against  the  exposed  gum,  the  vial  containing  the  ethyl  chlorid  being 
held  about  a  foot  from  the  mouth.  When  the  gum  becomes  intensely 
anemic,  indicated  by  pronounced  whiteness,  the  tooth  is  to  be  extracted. 
Ethyl  chlorid  must  be  kept  in  a  cool  place,  and  far  from  any  flame ;  it 
is  inflammable  and  explosive. 

Preparations  containing  cocain  (benzoyl-methyl-ecgonin)  have  to 
a  great  extent  superseded  all  other  local  anesthetics  employed  for  this 
purpose.  It  was  clearly  shown  soon  after  the  introduction  of  this 
alkaloid  that  its  local  anesthetic  action  when  applied  to  the  gums  did 
not  extend  beyond  the  depth  of  the  mucous  membrane,  so  that  its  epi- 
dermic application  does  not  render  the  operation  of  tooth  extraction 
painless.  The  hypodermatic  application  was  found  to  render  the  tissues 
infiltrated  perfectly  analgesic.  A  recklessness  was  evinced  in  its  use 
after  this  method  which  was  promptly  followed  by  repeated  disasters ; 

631 


632  LOCAL  ANESTHETICS  AND  TOOTH  EXTRACTION. 

a  formidable  list  of  casunltios  grow.  Reports  of  cases  of  resjiiratory 
and  of  cardiac  paralysis  following  its  employment  were  not  uncommon. 
It  apparently  needed  disaster  to  demonstrate  that  cocain  belonged  in  the 
category  of  actively  poisonous  alkaloids,  being  by  no  means  the  bland 
and  safe  agent  many  operators  seemed  to  think  it.  This  lesson,  learned 
at  great  cost,  is  one  the  operator  is  ever  to  heed,  particularly  in  the 
hypodermatic  employment  of  the  agent.  Dr.  M.  H.  Cryer  has  re- 
ported^ cases  of  ascending  degeneration  of  the  trunks  of  the  maxillary 
nerves  following  upon  cocain  injections  about  the  jaws. 

For  the  origin,  composition,  physiological  effects,  and  toxicology  of 
the  drug  the  student  is  referred  to  the  standard  works  upon  materia 
medica.  There  are  several  points,  however,  which  cannot  be  over- 
emphasized, the  first  being  in  regard  to  the  drug  itself.  A  full  dose  of 
cocain  hydrochlorid  by  the  stomach  is  about  gr.  |.  The  composition 
of  the  commercial  specimens  is  not  constant ;  some  of  them  appear  to 
contain  the  actively  poisonous  alkaloid  isatropylcocain.  A  safe  dose 
when  applied  hypodermatically  is  not  in  excess  of  gr.  \. 

The  lethal  effect  of  cocain  is  upon  the  respiratory  centre.  Its 
absorption  is  followed  by  a  stimulation  of  the  cardiac  and  respira- 
tory functions,  which  is  commonly  followed  by  a  reaction,  the  stimu- 
lation giving  way  to  depression.  Idiosyncrasies  as  to  the  effects  of 
cocain  are  common ;  cases  of  susceptible  women  have  been  noted  in 
which  gr.  ^  produced  toxic  effects.  It  is  to  be  noted  that  the  depres- 
sion following  as  a  secondary  effect  upon  the  primary  stimulation  may 
not  occur  for  an  hour  or  later. 

In  prescribing  cocain  for  hypodermatic  injection,  the  analgesic  is 
the  first  element  to  be  considered  in  the  prescription.  The  dose  is  not 
to  exceed  gr.  ^.  The  second  factor  demanding  attention  is  a  physio- 
logical antidote,  one  which  will  not  neutralize  the  analgesic  effect  and 
yet  will  prevent  the  toxic  action  of  the  cocain  upon  the  cardiac  and 
respiratory  functions.  Morphin  is  that  agent.  As  its  full  physiological 
effect  is  not  required,  a  small  dose,  gr.  -^,  will  be  sufficient.  The  next 
ingredient  of  the  prescription  is  an  agent  which  shall  prevent  abrupt 
spastic  contraction  of  the  arteries  and  heart.  Trinitrin  is  this  agent. 
One  drop  of  the  1   per  cent,  solution  is  the  indicated  dose. 

Fungi  develop  freely  in  solutions  of  cocain,  so  that  if  the  pre- 
scription is  to  be  a  permanent  solution,  an  antiseptic  is  required  to 
prevent  decomposition.  Cinnamic  alcohol  answers  well  for  this  pur- 
pose. One  drop  of  carbolic  acid  to  each  half-grain  of  cocain  is  an 
efficient  antiseptic.  By  boiling  cocain  is  split  up  into  methyl,  benzoic 
acid,  and  ecgonin,  so  that  cocain  solutions  cannot  be  sterilized  by 
boiling. 

'  Proc.  Academy  of  Stomatolocjif,  Philadelphia,  1896. 


COCAIN.  633 

The  dose  commonly  employed  of  the  components  of  the  prescription 
is — 


Cocainse  hydrochlorid.,    • 

gr.  i ; 

Morphinse  sulph., 

gr.  iV; 

or  Atropinse  sulph., 

gr-  lU; 

Trinitrin.  (1  per  cent,  sol.), 

gtt.j; 

Acid,  carbolic, 

gtt.  j ; 

Aqu£e, 

q.  s.  3SS. — M. 

S.  The  above  represents  a  half-syringeful  and  is  a  full  dose. 

This  solution  has  been  employed  with  general  success,  provided 
strict  antiseptic  precautions  have  been  taken.  Untoward  results  are 
occasionally  found  even  with  this  seemingly  safe  formula. 

In  the  hypodermatic  use  of  cocain  the  relatively  safe  maximum  dose 
should  never  be  exceeded  and  the  exact  amount  administered  in  a  given 
case  always  definitely  known.  A  common  error  has  been  the  dependence 
upon  solutions  of  a  given  percentage  composition.  The  danger  of  such 
dependence  becomes  evident  when  it  is  considered  that  the  safe  maxi- 
mum dose  of  cocain  salt  may  be  easily  exceeded  by  the  use  of  a  sufficient 
quantity  of  a  low-percentage  solution,  while  on  the  other  hand  it  is 
quite  possible  to  keep  within  the  limits  of  safety  by  using  minute 
quantities  of  a  high-percentage  solution.  The  supposed  harmlessness 
of  a  dilute  cocain  solution  is  erroneous  and  misleading  unless  the  factor 
of  the  absolute  quantity  of  the  drug  contained  in  a  given  amount  of 
solution  is  constantly  kept  in  mind. 

A  method  which  is  in  all  respects  safer  and  which  enables  the  oper- 
ator at  all  times  to  know  the  exact  amount  of  cocain  salt  injected  is  to 
make  the  solution  upon  the  basis  of  eight  grains  of  the  salt  to  one  ounce 
of  the  menstruum,  which  will  give  one  grain  in  each  drachm  and  -^^  of 
a  grain  in  each  minim.  Of  such  a  solution  from  five  to  eight  minims 
may  be  injected  about  a  tooth  with  a  reasonable  degree  of  assurance 
that  the  safe  limits  of  physiological  effect  have  not  been  exceeded. 

The  menstruum  in  which  these  ingredients  are  combined  is  an  inter- 
esting feature.  It  has  been  repeatedly  shown  that  the  injection  of  a 
quantity  of  water  will  produce  anesthesia  of  a  region.  The  nerve  fila- 
ments are  compressed  by  the  fluid  and  do  not  transmit  painful  impres- 
sions. 

Dr.  Schleich  of  Greifswald  ^  follows,  for  the  induction  of  local  anes- 
thesia for  operations  in  general  surgery,  an  infiltration  method.  The 
injection  is  divided  and  the  punctures  made  seriatim  about  the  territory 
to  be  operated  upon.  The  remarkable  feature  of  his  procedure  is  the 
minute  dose  employed.  He  uses  a  1  :  4000  solution  of  cocain,  to  which 
1  T.  Parvin,  Proc.  Phila.  Co.  Med.  Soc,  Nov.  13,  1895. 


634  LOCAL  ANESTHETICS  AND   TOOTH  EXTRACTION. 

is  added  I  of  1  j)or  cent,  sodium  chlorid  and  a  small  <juantity  of  4  per 
cent,  tricresol.  One  syringefiil,  about  a  drachm,  is  sutlicient  to  infil- 
trate the  tissues  about  a  tooth  and  render  its  extraction  painless.  A 
drachm  of  the  1  :40()0  solution  contains  about  gr.  -^-^  of  cocain.  The 
strongest  solution  employed  by  Schleich  is  a  1  :  500.  A  drachm  of  such 
a  solution  would  contain  less  than  gr.  ^  of  cocain.  Dr.  W.  F.  I^itch 
(ibid.)  has  pointed  out  that  low-percentage  solutions  will  give  a  safer 
result  than  those  of  high  percentage,  even  though  the  absolute  amount 
of  the  drug  should  be  the  same.  It  is  seen,  therefore,  that  the  quan- 
tity of  menstruum  in  which  the  dose  of  cocain  is  suspended  is  an  im- 
portant consideration. 

Tablets  for  making  Schleich's  solutions  may  be  had  of  pharmaceu- 
tists.    Tablets  for  making  the  strong  solution  contain — 

!^.  Coca i use  hydrochl.,  gr.  ^; 

Morphinae  hydrochl.,  gr.  -^ ; 

Sodii  chlorid.,  gr.  ^, 
S.  Dissolve  in  TTL  100  of  distilled  water. 

Prof.  E.  Sauvez*  records  15,000  injections  of  cocain  for  local  anes- 
thesia in  tooth  extraction  without  accident,  and  quotes  a  record  of  7000 
cases  of  cocain  anesthesia  by  Prof.  Reclus  with  entire  success. 

Sauvez  recommends  the  use  of  not  over  1  c.c.  of  a  1  per  cent, 
solution  of  cocain  hydrochlorid  in  distilled  water.  This  amount  may 
be  injected  safely  with  the  patient  in  the  sitting  posture,  and  without 
danger  of  syncope.  When  more  than  1  centigram  (.154  grain)  is  in- 
jected the  patient  should  be  recumbent. 

Stovaine  is  the  designation  of  a  new  local  anesthetic  recently  discov- 
ered by  M.  Forneau,  and  is  said  to  possess  certain  advantages  over 
cocain.  According  to  Sauvez,  it  is  not  more  than  one-half  as  toxic  as 
cocain,  and  possesses  a  vaso-dilator  action  instead  of  the  vaso-constrictor 
action  of  cocain.  It  is  equal  in  anesthetic  property  to  cocain  and  less 
costly.  Sauvez  has  used  it  in  100  cases,  in  doses  of  1  c.c.  of  a  .75  :  100 
solution. 

Almost  without  exception  the  nostrums  advertised  and  sold  under 
high-sounding  titles,  for  employment  in  this  field,  contain  cocain. 
Neither  their  names  nor  any  information  vouchsafed  by  their  venders 
give  any  indication  of  the  amount  of  alkaloid  present,  and  so  all  of 
them  should  be  tabooed.  It  is  nothing  short  of  criminal  to  employ 
these  nostrums  without  a  knowledge  of  their  exact  composition. 

Tropacocain  (benzoyl  pseudo-tropin)  has  been  employed  to  render 

^  "  A  Study  of  the  Best  Means  of  Local  Anesthesia  for  the  Extraction  of  Teeth,"  hy 
Dr.  E.  Sauvez,  Proceedings  Fourth  International  Dental  Congress. 


SCHLEICB'S  SOLUTIONS.  635 

the  operation  of  tooth  extraction  painless.  It  possesses  decided  advan- 
tages over  cocain.  It  is  only  one-half  as  toxic ;  has  but  slightly  de- 
pressant action  upon  the  cardiac  ganglia ;  has  no  paralyzant  action  upon 
the  respiration ;  anesthesia  is  more  quickly  produced,  and  its  solutions 
are  slightly  antiseptic.  Solutions  of  the  drug  are  made  in  distilled 
water ;  the  full  dose  is  gr.  ^  to  f . 

The  reader,  of  course,  at  once  draws  the  correct  inference  that 
Schleich's  method  gives  promise  of  safety.  Applications  made  hypo- 
derm  atically  of  the  elaborated  prescription  presented  are  not  without 
danger  even  in  physiological  dose. 

It  is  necessary  that  the  field  of  operation  be  made  aseptic  before 
injection.  The  mouth  should  be  washed  repeatedly  with  a  powerful 
antiseptic,  3  per  cent,  pyrozone,  10  per  cent,  electrozone,  or  3  per  cent, 
formaldehyd  solution. 

The  syringe  should  be  aseptic ;  repeated  washing  of  syringe  and 
points  in  a  25  per  cent,  solution  of  phenol  sodique  will  serve  this  end 
without  detriment  to  the  syringe  piston  or  the  metallic  parts  of  the 
syringe.  A  syringe  having  stout  finger-rests  and  holding  one  drachm 
is  employed.  The  needles  should  be  reinforced  for  half  their  length, 
and  should  have  sharp,  fine  points. 

The  gum  is  to  be  dried  and  touched  with  a  20  per  cent,  solution  of 
cocain ;  in  five  minutes  the  needle  may  be  inserted  painlessly.  The 
syringe  is  filled  with  the  analgesic  solution,  the  needle  screwed  on,  and 
the  piston  pressed  down  until  all  air  is  expelled  from  the  syringe  and 
needle.  The  latter  is  now  thrust  into  the  gum  about  midway  between 
the  neck  of  the  tooth  and  the  apex  of  the  root,  until  it  comes  in  contact 
with  the  alveolar  process,  when  it  is  slightly  withdrawn  and  a  few 
drops  of  the  solution  are  driven  into  the  tissues.  A  second  injection  is 
made  over  the  apex  of  the  root ;  if  the  strong  solutions  be  used,  the 
amount  of  fluid  injected  must  not  contain  more  than  gr.  i-  of  cocain ; 
even  though  several  punctures  be  made.  Care  must  be  exercised  to 
confine  the  injection  to  the  tissues  of  the  gum ;  if  the  submucous  tissue 
beneath  the  junction  of  the  cheek  and  gum  be  injected  into,  alarming 
emphysema  may  result. 

For  multirooted  teeth  an  injection  is  made  over  each  root.  If 
Schleich's  solution  be  employed,  a  full  drachm  of  fluid  should  be  in- 
jected, until  the  gum  over  the  tooth  is  tense  and  white,  when  extrac- 
tion may  be  accomplished  painlessly. 

In  some  instances  the  intense  anemia  present  at  the  moment  of 
extraction  may  be  succeeded  by  local  hemorrhage  as  soon  as  reaction 
is  established.  An  antiseptic  hemostatic  should  be  applied  to  the 
alveolus  after  extraction ;  phenol  sodique,  full  strength,  is  an  admirable 
agent  for  this  purpose. 


636  LOCAL  ANESTHETICS  AXD   TOOTH  EXTRACTION. 

The  imminent  dangers  to  be  feared  in  this  connection  are  :  first,  the 
toxic  effects  of  the  drug.  As  these  are  usually  manifested  in  contrac- 
tion of  the  bloodvessels  the  antidote  is  amyl  nitrite.  A  supply  of  pearls 
each  containing  TDiijof  amyl  nitrite  should  be  kept  in  the  medicine 
cabinet.  AVhcn  a  patient  exhibits  great  pallor,  a  snuill  pulse,  and  bluish- 
white  lips,  one  of  these  pearls  is  crushed  in  a  napkin  and  the  nitrite 
(piickly  iidialed.  The  conjoint  administration  of  gtt.  xx.  aromatic 
spirits  of  ammonia,  or  about  half  an  ounce  of  brandy,  is  advised. 
Should  these  measures  not  prove  promptly  effective,  artificial  respiration 
should  be  immediately  begun  and  be  prosecuted  vigorously. 

The  second  danger  is  septic  infection,  either  through  im})erfectly 
sterilized  instruments  or  by  carrying  septic  organisms  from  the  mucous 
membrane  covering  the  gum  into  the  deeper  tissues  during  the  opera- 
tion of  injection.  This  is  avoided  by  a  careful  sterilization  of  the 
syringe  before  it  is  used,  and  the  repeated  applications  of  antiseptic 
mouth-washes  previous  to  injection.  Prescriptions  which  contain  a 
large  percentage  of  carbolic  acid  are  liable  to  cause  sloughing. 

Injections  forced  between  the  periosteum  and  bone  may  produce 
serious  injury. 

The  introduction  of  eucain  as  a  local  anesthetic  was  due  to  the 
observed  chemical  similarity  of  that  synthetic  body  with  cocain ;  an 
instance  of  presaging  the  physiological  effects  of  a  drug  by  its  chemical 
composition.  Its  local  effect  upon  bloodvessels  is  to  produce  hyper- 
emia, instead  of  the  ischemia  induced  by  cocain.  It  is  less  poisonous  than 
cocain  and  its  solutions  are  chemically  more  stable.  Its  primary  action 
upon  the  central  nervous  system  is  one  of  exaltation,  and  this  is  followed 
by  paralysis,  the  effect  being  central,  not  ascending.  The  sedative 
central  influence  causes  a  quickening  of  the  heart-beats  through  sedation 
of  the  inhibitory  (pneumogastric)  nerves.  Although  eucain  is  less  toxic 
than  cocain  it  also  produces  a  greater  degree  of  analgesia ;  so  that  the 
dose  need  not  be  greater  than  that  of  cocain,  about  ^  to  |  of  a  grain 
being  the  maximum. 

Eucain  may  be  kept  in  permanent  and  stable  solution  in  distilled 
water.  A  10  per  cent,  solution  may  be  made  in  distilled  water  (48 
grains  of  eucain  hydrochlorid  to  the  ounce  of  distilled  water)  and  the 
solution  sterilized  by  boiling,  which  does  not  decompose  eucain.  From 
five  to  eight  minims  of  such  a  solution  is  a  proper  dose.  The  precau- 
tions to  be  observed  and  the  mode  of  application  are  the  same  as  for 
cocain. 

Besides  the  dangers  arising  from  the  hypodermatic  administration 
of  a  physiological  overdose  of  this  class  of  analgesic  drugs,  and  the  local 
danger  of  infection  from  non-sterile  solutions  or  instruments,  there  is  to 
be  strongly  emphasized  the  danger  of  local  necrosis  due  to  the  poisonous 


SCHLEICH'S  SOLUTIONS.  637 

effect  of  the  drugs  themselves  upon  the  tissue  elements  when  directly 
injected.  In  nearly  all  cases  in  which  extraction  is  sought  the  tissues 
about  the  tooth  are  in  a  condition  of  lowered  vitality,  brought  about  by 
the  local  toxemia  resulting  from  the  infection  which  has  produced  the 
inflammatory  process.  The  injection  of  a  protoplasmic  poison,  such  as 
cocain,  eucain,  and  their  congeners,  into  the  inflamed  territory  causes  a 
still  further  depression  of  vital  resistance,  which,  if  sufficiently  pro- 
nounced, may  become  total  and  permanent.  Hence,  tissue-death  or 
necrosis,  with  subsequent  sloughing,  will  necessarily  result. 

Where  the  inflammatory  process  about  a  tooth  is  at  all  pronounced, 
it  is  much  wiser  to  discard  local  anesthetic  methods  for  the  far  safer 
procedure  of  general  anesthesia  induced  by  nitrous  oxid  or  ether. 


CHAPTER    XXII. 
PLANTATION  OF  TEETH. 
By  Louis  Ottofy,  D.  D.  S. 


The  transplantation  of  a  tooth  signifies  the  insertion  of  a  nat- 
ural tooth  into  a  natural  alveolus  other  than  the  one  it  originally  occu- 
pied. The  tooth  may  be  an  old  and  dry  specimen  transplanted  into  an 
alveolus  from  which  a  tooth  has  been  recently  removed,  or  it  may  be  a 
freshly  extracted  tooth  transplanted  from  one  part  of  the  mouth  of  an 
individual  to  another  part  of  the  mouth  of  the  same  individual,  or  it 
may  be  a  freshly  extracted  tooth  transplanted  from  the  mouth  of  one 
person  into  that  of  another. 

Replantation  signifies  the  replacing  of  a  tooth  in  the  alveolus 
whence  it  had  been  removed  by  design  or  accident.  The  operation  may 
be  performed  at  once  or  at  any  time  before  the  socket  is  filled  with  new 
tissue. 

Under  the  term  implantation  are  included  all  those  operations 
which  involve  the  formation  of  an  artificial  alveolus  for  the  reception 
of  the  root  of  a  human  tooth.  The  operation  of  altering  the  size  or 
form  of  an  existing  alveolus  to  receive  a  tooth  belongs  to  this  class, 
although  it  is  a  combination  of  trans-  and  implantation. 

The  operation  of  replantation  probably  far  antedated  that  of  trans- 
plantation, as  the  latter  preceded  implantation,  but  its  definite  history 
is  unknown.  It  is  safe  to  presume  that  it  has  been  practiced  ever  since 
mankind  conceived  of  the  natural  healing  power  of  the  body.  Even 
when  performed  with  crudity  and  without  any  clear  comprehension 
of  the  mode  of  repair,  favorable  results  have  been  reported.  The  ope- 
ration is  at  present  an  uncommon  one  :  the  condition  for  the  relief  of 
which  it  was  at  one  time  practiced  with  comparative  frequency,  chronic 
alveolar  abscess,  has  been  found  amenable  to  less  radical  treatment. 

The  operation  of  transplantation  is  first  noted  in  the  writings  of 

Ambroise  Pare  in  the  sixteenth  century,  though  credit  has  generally 

been  given  to  Dr.  John   Hunter,    who  gave  the   subject   considerable 

attention.     Hunter's  experiment  of  implanting  a  tooth  in  the  comb  of 

a  cock  is  classical.     The  records  of  the  operation  do  not  exhibit  any 

6:9 


640 


PLANTATION  OF  TEETH. 


prcat  measure  of  suecess  attendinir  it.  Hunter  noted  eases  of  trans- 
plantation of  dead  teeth  which  remained  for  years. 

No  one  disputes  with  Dr.  Younger  of  San  Francisco  the  authorship 
of  the  operation  of  implantation.  The  date  of  his  first  operation  was 
June  15,  1885,  althou<ih  Bourdet  in  1780  was  the  first  to  mention  the 
operation,  stating  that  "  irresponsible  persons  claim  to  make  a  socket, 
and  im|)lant  into  it  a  tooth."  An  attempt  at  partial  implantation  is 
recorded   in   Dental  Vosmox,  vol.  xix.  j).  258. 

In  order  that  an  intelligent  conception  may  be  had  of  the  intimate 
nature  of  the  biological  conditions  which  surround  the  teeth  after  inser- 
tion by  either  of  these  operations,  it  is  essential  to  study  the  general 


Fig.  568. 


Fig.  569. 


1       5      1 

A  tooth  and  its  normal  attachment  and  vascular 
supply :  1,  1,  Apical  pericementum  in  which 
is  seen  the  main  pericemental  artery,  5  ;  2,  2, 
anastomosing  bloodvessels  or  channels*  of 
the  alveolar  walls;  3,  3,  the  marginal  anasto- 
mosis of  alveolar  and  pericemental  arteries. 


Conditions  following  replantation  :  1,  1',  The 
pericementum  and  inflammatory  eft'usion 
between  pericementum  and  alveolar 
walls ;  2,  2,  source  of  blood-supply  to  the 
area  of  repair;  3,  3,  terminations  of  alveo- 
lar arteries ;  5,  obliterated  apical  artery. 


processes  which  attend  the  repair  of  tissues,  and  their  behavior  toward 
foreign  bodies. 

As  all  of  these  operations  are  performed  under  the  strictest  antiseptic 
precautions,  the  consideration  of  bacterial  influence  is  omitted  at  this 
juncture.  As  it  is  impossible  to  secure  specimens  which  would  show 
these  several  parts  in  their  true  relations,  the  illustrations  are  neces- 
sarily diagrammatic  and  theoretical. 

'  Figs.  568-571  are  from  drawings  by  Dr.  H.  H.  Burcliard. 


BIOLOGICAL  CONDITIONS  IN  PLANTATION 


641 


Fig.  568  exhibits  a  longitudinal  section  of  an  incisor,  its  attachments 
and  support,  together  with  its  vascular  supply,  in  its  normal  relations, 
the  bloodvessels  from  the  pericementum  anastomosing  with  those  of 
the  alveolar  periosteum.  The  pericemental  space  is  filled  with  fibrous 
tissue.     To  avoid  confusion  the  nerves  and  veins  have  been  omitted. 

Fig.  569  represents  the  conditions  following  replantation.  The  tooth 
has  been  sterilized  and  its  pulp  canal  hermetically  sealed.  The  perice- 
mental bloodvessels  have  been  destroyed  in  extraction.  Portions  of 
the  pericementum  are  seen  clinging  as  fibrous  remnants  to  the  ceraen- 
tum.    The  remainder  of  the  alveolus  is  filled  with  inflammatory  corpus- 


FiG.  570. 


Fig.  571. 


Conditions  following  transplantation  :  1,  1', 
Embryonic  tissue  which  will  be  organ- 
ized into  repair  tissue  replacing  the 
original  pericementum ;  5,  obliterated 
apical  vessels. 


Conditions  following  implantation :  1, 1,  Alveo- 
lar arteries  ;  2,  2,  gingival  margin ;  3,  inflam- 
matory still  unorganized  tissue  filling  the 
space  between  the  cementum  and  walls  of 
the  artificial  alveolus ;  4,  4,  phagocytes,  mul- 
tinucleated cells  attacking  cementum  of  im- 
planted tooth ;  5,  obliterated  apical  vessels. 


cles.  The  vascular  supply  to  the  regenerated  pseudo-pericementum  is 
derived  first  from  the  vessels  of  the  alveolar  periosteum  via  the  alveolar 
process. 

Fig.  570  shows  the  conditions  existing  soon  after  the  operation  of 
transplantation.  The  mechanical  violence  of  extraction  has  irregularly 
enlarged  the  natural  alveolus.  The  tooth,  its  apex  rounded,  is  shown 
with  the  blunted  extremity.  The  vascular  supply  is  similar  to  that 
of  Fig.  569.     The  alveolar  space  is  filled  with  inflammatory  corpuscles. 

41 


642  PLAXTATfoy  OF  TEKTIL 

Fifj.  571  o.\hil)its  the  conditions  j)rohal)ly  oxi.stoiit  soon  after  an  im- 
plantation operation.  The  vascular  supply  is  tlie  stinie  as  shown  in  Figs. 
569  and  570.  Instead  of  having  a  layer  of  periosteal  hone,  the  for- 
mation of  the  artificial  alveolus  is  into  the  spongy  medullary  hone. 
The  artificial  alveolus,  being  necessarily  difierent  in  size  and  outline 
from  the  tooth,  is  filled  with  inflammatory  products.  Some  of  the  cells, 
becoming  multi-nucleated,  are  seen  to  be  exercising  their  phagocytic — 
or,  in  this  connection,  resorptive — function  upon  the  cementum. 

Replantation  and  Transplantation. 

Replantation. — In  the  present  state  of  dental  practice  the  following 
conditions  may  be  regarded  as  warranting  replantation  : 

(1)  When  a  tooth  has  been  dislodged  by  traumatism,  a  blow  by  a 
ball,  club,  or  fall,  etc. 

(2)  When  a  tooth  has  been  accidentally  removed  by  the  slipping  of 
the  forceps  during  the  performance  of  a  dental  extraction. 

(3)  When  some  disease,  otherwise  incurable,  aifects  either  the  root  or 
some  portion  of  its  alveolus. 

The  first  two  causes  are  practically  the  most  frequent  under  which 
replantation  is  justifiable. 

In  case  a  tooth  has  thus  been  dislodged  and  found,  it  should  at  once 
be  cleansed  of  all  foreign  matter  and  then  be  carefully  examined  for 
fractures  or  other  injury.  Any  cavities  present  should  be  filled,  the 
contents  of  the  root  canal  removed,  and  the  space  filled  in  the  manner 
described  later  ;  fractured  or  abraded  portions  or  surfaces  are  to  be  made 
smooth,  and  the  tooth  placed  in  an  antiseptic  solution.  A  careful  ex- 
amination of  the  socket  should  then  be  made.  It  will  be  noticed  when 
the  accident  has  befallen  a  young  individual,  that  as  a  result  of  the 
flexibility  of  the  bone,  the  alveolar  process  is  seldom  fractured — an 
accident  more  prone  to  happen  in  adult  life. 

Some  discrimination  should  be  exercised  as  to  the  promptness  with 
which  to  replant  the  tooth.  If  there  is  considerable  inflammation  as 
the  result  of  injury,  it  is  not  advisable  to  immediately  replace  the  tooth. 
In  that  event  the  socket  should  be  made  aseptic  and  if  possible  normal 
hemorrhage  re-established.  As  a  general  rule  several  days  should  be 
allowed  to  intervene  when  the  inflammation  is  excessive  ;  otherwise  a 
tooth  may  be  replaced  at  any  time  as  soon  as  it  has  been  prepared. 

The  governing  pathological  principle  is  as  follows  :  Immediately  after 
an  injury,  a  certain  amount  of  inflammation  takes  place  and  there  is 
retrograde  metamorphosis — a  destruction  or  breaking  down  of  tissue  ; 
and  this  is  not  the  most  favorable  time  to  expect  re-attachment  to  take 
place.     As  a  rule,  within  a  few  days  a  build'ng-up  process,  constructive 


REPLANTATION  AND  TRANSPLANTATION.  643 

metamorphosis,  has  set  in,  and  the  replacement  of  a  tooth  at  this  time  is 
likely  to  be  followed  by  more  favorable  results.  This  period  sets  in  at  any 
time  from  three  days  to  a  week,  the  socket  being  then  partially  filled 
with  active  living  cells.  Just  prior  to  the  replacement  of  the  tooth  the 
socket  and  the  gum  surrounding  it  having  been  cleansed  and  sterilized, 
the  tooth  itself  being  brought  forth  from  its  antiseptic  medium,  it  must 
be  promptly  replanted.  As  a  rule,  constant  but  not  severe  pressure  will 
permit  the  tooth  to  assume  its  original  position  in  the  socket,  although 
sometimes  it  is  necessary  to  remove  a  part  of  the  apex  of  the  root  or 
slightly  deepen  the  socket  by  means  of  a  suitably  shaped  bur.  It  hap- 
pens occasionally  that  the  location  of  the  tooth  and  the  general  surround- 
ings are  such  that  a  tooth  like  this  may  be  retained  without  any  further 
attachment,  but  as  a  rule  it  is  not  safe  to  trust  to  uncertainties  regarding 
the  attachment  of  the  tooth.  An  impression  of  the  tooth  and  its  neigh- 
bors can  be  quickly  secured  with  Melotte's  compound  or  in  clay,  a  die 
is  easily  made,  from  which  a  cap,  such  as  will  be  described,  is  quickly 
made. 

It  is  needless  to  dwell  upon  the  second  cause  mentioned.  No  dentist 
can  ever  be  excused  for  accidentally  removing  a  sound  tooth,  but  in 
case  the  accident  does  happen  the  above  procedure  is  indicated. 

The  opportunities  enumerated  under  the  third  section  are  also,  for- 
tunately, exceedingly  rare.  The  cases  in  which  formerly  replantation 
was  resorted  to,  on  the  ground  that  the  case  was  incurable,  are  now 
much  less  frequently  met  with,  and  when  they  are  encountered  they 
often  yield  to  treatment,  which  is  now  more  clearly  understood — such 
as  amputation  of  the  root,  removal  of  the  necrosed  portion  of  the 
alveolar  process,  etc.  When,  however,  it  has  been  decided  to  extract 
a  diseased  tooth  and  to  replant  it,  diseased  portions  of  the  root  should 
be  removed  and  a  sufficient  time  allowed  to  elapse  before  replantation 
for  the  socket  and  tissues  to  have  assumed  a  healthy  aspect,  even  if 
this  should  necessitate  the  enlargement  of  the  socket. 

In  cases  of  pyorrhea  alveolaris,  which  sometimes  has  been  suggested 
as  coming  under  this  class,  treatment  by  replantation  is  out  of  the  ques- 
tion, provided  the  case  has  made  sufficient  progress  to  suggest  such 
a  course.  Replantation  implies  the  presence  of  a  socket,  and  when 
pyorrhea  alveolaris  has  made  any  great  degree  of  progress,  the  socket 
is  wanting.  Hence  it  is  but  in  rare  cases  that  an  attempt  to  cure  by 
this  method  is  justifiable. 

Dr.  Louis  Jack  ^  has  recorded  marked  success  in  several  cases  at- 
tending an  operation  of  modified  replantation  for  the  cure  of  some  of 
the  earlier  phenomena  of  phagedenic  pericementitis,  notably  the  common 
malposition  due  to  what  has  been  termed  voluntary  tooth  movement. 
^  See  Trans.  Academy  of  Stomatology,  1895. 


644  PLANTATION  OF  TEETH. 

Transplantation. — Tlioro  i.s  a  hroador  range  tor  the  practice  of 
transplantation  than  either  of  the  other  operations  treated  in  this 
chapter.  As  has  been  seen,  replantation  is  limited  in  its  application, 
and  implantation  must,  from  the  nature  of  the  operation,  be  also  con- 
fined to  a  comparatively  circumscribed  sphere. 

The  operation  may  be  performed  at  any  period  of  an  individual's 
life,  although  as  a  rule  young,  vigorous,  and  mature  adult  life  offers  the 
greatest  promise  of  success.  Any  socket  in  any  part  of  the  mouth, 
when  placed  in  a  healthy  condition,  is  a  more  or  less  favorable  location 
for  the  reception  of  a  tooth  about  to  i)e  transplanted.  It  is  true  that 
sometimes  a  socket  needs  to  be  enlarged  or  deepened  for  this  purpose, 
but  this  is  a  comparatively  simple  matter.  Before  the  advent  of  the 
intelligent  practice  of  crown  and  bridge  work,  treatment  of  diseases 
of  the  pulp  and  peridental  membrane,  the  bleaching  of  teeth,  and  the 
intelligent  practice  of  orthodontia,  transplantation  was  resorted  to  as  a 
remedy  for  the  correction  of  many  trivial  disorders.  In  the  light  of 
the  present  day,  transplantation  is  confined  to  sockets  whence  teeth 
have  been  removed  for  any  cause  which  could  not  be  remedied  by  some 
other  method  of  treatment :  sockets  which  remain  as  the  result  of  the 
loss  of  teeth  from  accident  of  any  kind  (the  lost  teeth  not  having  been 
recovered) ;  from  which  roots  beyond  salvation  have  been  extracted  ; 
from  which  diseased  teeth  must  be  removed  ;  from  which  roots  have 
been  renidvod  having  carried  crowns  or  having  served  as  abutments  for 
bridges  until  their  period  of  usefulness  has  passed. 

The  same  rule  laid  down  for  the  care  of  a  socket  previous  to  re- 
plantation holds  good  for  transplantation  ;  namely,  that  inflammation 
must  be  reduced,  and  the  tooth  transplanted  into  the  socket  at  a  time 
when  progressive  constructive  metamorphosis  is  taking  place.  This 
period  is  stated  as  usually  from  three  to  seven  days  after  the  removal 
of  the  tooth.  In  instances  where  considerable  disease,  such  as  a  chronic 
alveolar  abscess  of  years'  standing  has  been  present,  even  a  longer  time 
should  be  allowed  to  intervene  before  transplantation. 

Preparation  of  Teeth  for  Plantation. 

"With  the  exception  of  such  special  directions  as  are  necessary  in 
each  class  of  the  operations  described  in  this  chapter,  the  following 
general  directions  are  ap])licable  to  all  cases. 

The  Scion  Tooth. — For  replantation  a  recently  dislodged  tooth  is 
supposed  to  be  at  hand,  hence  there  is  a  fresh  tooth.  For  transplanta- 
tion it  is  implied  that  the  tooth  is  either  at  hand  or  about  to  be  secured, 
but  in  a  ease  of  transplantation  or  implantation  the  age  of  the  tooth 
may  bo  unknown  and  indefinite.  Teeth  have  been  planted  whose  age 
and  origin  have  been  absolutely  unknown,  and  they  have  become  firm 


PREPARATION  OF  TEETH  FOR  PLANTATION.  645 

in  their  new  locations.  Nevertheless  it  seems  reasonable  to  take  the 
ground  that  whenever  it  is  possible,  teeth  should  be  fresh  and  something 
of  their  previous  environment  should  be  known.  There  are  no  cases 
on  record  where  disease  has  been  transmitted  through  the  medium  of  a 
planted  tooth,  although  portions  of  the  early  literature  of  this  subject  do 
indicate  such  results.  The  principal  objection  to  old  and  dry  teeth  is 
that,  the  water  having  been  evaporated,  these  teeth  are  almost  invaria- 
bly fractured  or  cracked  from  shrinkage.  When  these  fractures  extend 
to  the  crown  portion,  the  enamel  frequently  chips  oflP  within  a  short 
time  after  the  tooth  has  been  planted  ;  while  in  some  instances  the 
entire  root  has  been  fractured.  Another  objection  to  teeth  promiscu- 
ously gathered  is  that  it  is  seldom  possible  to  find  teeth  in  which  the 
crowns  are  sufficiently  perfect  to  be  serviceable  and  to  be  presentable 
in  the  mouth.  The  crown  of  a  dry  tooth  permits  of  but  slight  altera- 
tion with  the  grinding  stone  or  sandpaper  disk  without  endangering  its 
integrity ;  while  if  it  is  aifected  by  caries  to  such  an  extent  as  to  require 
an  extensive  operation,  the  life  of  the  filling  is  likely  to  be  of  shorter 
duration  than  a  similar  operation  performed  on  a  freshly  extracted  tooth 
or  a  tooth  with  living  connections.  For  this  reason  it  is  preferable  to 
use  only  the  roots  of  teeth,  attaching  to  them  artificial  crowns.  This 
permits  the  selection  of  a  crown  suitable  in  size,  color,  and  shape,  and 
which  may  be  ground  for  articulating  purposes — an  important  matter 
in  these  cases. 

If  therefore  an  old,  dry  tooth  must  be  used,  let  it  be  carefully 
selected  with  regard  to  the  absence  of  checks  or  cracks  or  fractures, 
and  if  it  be  impossible  to  secure  a  tooth  with  such  a  crown,  let  there  be 
selected  a  good  root  to  which  a  crown,  as  described  later,  can  be 
attached. 

If  a  freshly  extracted  tooth  can  be  secured,  even  though  the  crown 
may  be  slightly  carious,  the  necessary  filling  operation  is  advisable,  and 
such  a  tooth  should  be  used,  if  possible. 

Root-filling. — Roots  may  be  filled  either  from  the  apex  or  through 
an  opening  or  cavity  in  the  crown.  Gutta-percha  seems  to  answer  all 
the  necessary  purposes,  but  for  a  short  distance  from  the  apical  extrem- 
ity it  is  well  to  fill  with  gold  wire  or  foil. 

Pericementum. — The  theory  that  the  pericementum  becomes  revivi- 
fied does  not  seem  to  be  tenable ;  at  least  the  proposition  that  life  is 
maintained  in  the  pericementum  for  any  considerable  period  of  time 
after  the  tooth  has  been  removed  from  vital  attachment  is  not  in  accord 
with  general  physiological  laws,  although  periosteum  as  a  tissue  main- 
tains its  vitality  for  a  time  after  separation.^  For  the  purpose  of  secur- 
ing an  attachment  there  is  no  necessity  for  the  presence  of  the  peric^ 
.   '  See  Ziegler's  General  Pathology. 


64G  PLANTATION  OF  TEETH. 

niontiim  ;  but  it  is  roasonnhlo  to  assume  that  the  nearer  to  natural  states 
the  root  and  the  socket  are  in,  tlie  more  favorahh-  will  l)e  th<'  proj^nosis. 
It  is  therefore  a  safe  rule  to  folloAV,  to  preserve  as  much  of  the  perice- 
mentum as  is  possible.  The  preservation  of  the  periccnuntum  has  an 
advantage  from  the  fact  that  after  the  tooth  has  been  })lanted,  the  peri- 
cementum under  the  influences  of  bodily  heat  and  moisture  expands 
and  thus  acts  in  the  nature  of  a  sponge  graft,  enabling  the  tissues  to 
more  quickly  obliterate  spaces  which  are  present  and  to  attach  them- 
selves to   the  root. 

Subsequent  Care  of  Planted  Teeth. — Numerous  methods  for  the 
retention  of  planted  teeth  have  been  recommended  by  various  authors 
at  ditierent  times.  AVhilc  many  of  them  are  original  and  ingenious,  all 
are  to  be  condemned  except  those  means  which  look  to  the  firm,  rigid, 
immovable  retention  of  the  planted  tooth  for  a  definite  period,  that  of 
surgical  re})air.  Neither  the  rubber-dam  splint,  silk  ligature,  nor  gold 
or  other  metal  wire  comes  under  this  heading.  Planted  teeth  must  be 
retained  immovably  for  a  period  of  two  to  six  weeks,  occasionally  from 
two  to  eight,  ten,  or  twelve  weeks.  The  shortest  time  of  immobility 
consistent  M'ith  subsequent  attachment  is  preferable.  The  tooth  to  be 
transplanted  or  implanted  should  be  fitted  after  jjreparation  in  a  model, 
made  from  an  im])ression  of  the  gum  where  the  tooth  is  to  be  planted 
and  of  the  adjoining  teeth,  as  shown  in  Fig.  572. 

An  impression  is  then  taken  of  it  and  of  the  adjoining  teeth  on  each 
side.  A  retention  cap  is  then  swaged  to  cover  the  grinding  surfaces 
of  three  or  more  teeth,  half  the  length  of  the  crown  on  the  labial  surface 
and  nearly  the  full  length  on  the  lingual  or  palatal  surface,  as  shown 
in  Fig.  573. 


Fir.,  r,:;}. 


Model  showing  prepared  tooth  in  place :  Model  showing  retention  cap 

a,  Gold  filling  at  cervical  joint.  »"  «'«• 

The  cap  may  be  made  of  pure  gold,  platinum,  or  German  silver. 
The  gauge,  according  to  the  metal  used,  should  be  from  No.  32  to 
No.  38.  This  cap  is  cemented  upon  the  crowns  adjoining  the  planted 
tooth  in  such  a  manner  that  it  mav  be  removed  without  disturbing  the 


PREPARATION  OF  TEETH  FOR  PLANTATION.  G47 

planted  tooth.  The  operator  can  remove  the  cap  by  springing  the 
metal  away  from  the  teeth,  examine  the  condition  of  attachment  of  the 
planted  tooth,  and  replace  the  cap  if  it  should  be  necessary.  Where 
the  articulation  interferes  with  the  retention  of  the  cap,  the  latter  may 
be  ligated  to  the  adjoining  teeth  in  addition  to  being  cemented  to  them, 
and  still  admit  of  removal  without  disturbing  the  planted  tooth.  There 
is  at  present  no  method  of  ligaturing  or  banding  the  teeth  which  will 
permit  removal  of  the  ligature  or  band  without  more  or  less  disturbance 
of  the  planted  tooth. 

Aside  from  the  necessity  of  immobility  for  a  certain  period,  the 
planted  tooth  and  surrounding  tissue  generally  require  but  little  atten- 
tion. In  occasional  cases  the  tissues  may  be  stimulated,  by  painting 
the  gum  with  a  mixture  of  equal  parts  of  tincture  of  aconite  root, 
chloroform,  and  iodin  paint  (the  latter  is  a  saturated  solution  of  iodin 
in  alcohol),  or  by  the  use  of  stimulating  mouth-washes,  notably  those 
containing  capsicum.  The  patient  should  be  cautioned  to  encourage 
the  downward  growth  of  the  gum  by  the  use  of  the  toothbrush,  to 
prevent  the  accumulation  of  remnants  of  food  or  saliva,  and  to  pre- 
vent their  subsequent  putrefaction  should  particles  become  unavoidably 
lodged  around  the  tooth  or  cap.  This  is  best  accomplished  by  using  a 
camel' s-hair  brush  dipped  in  hydrogen  dioxid  or  pyrozone,  electrozone, 
meditrina,  etc.,  washing  out  the  interstices  frequently.  A  syringe  or 
spray  from  an  atomizer  may  be  used. 

Artificial  Roots. — Experiments  have  been  performed  looking 
toward  the  use  of  roots  other  than  those  of  natural  teeth.  Koots  made 
of  ivory,  corrugated  or  perforated  porcelain,  lead,  gold,  platinum,  and 
other  metals  have  been  used.  The  writer's  experiments  in  this  direc- 
tion have  all  resulted  in  failure.  There  is  no  recorded  evidence  that 
any  have  resulted  successfully. 

Mode  of  Attachment. — xA.s  to  the  mode  of  attachment  of  planted 
teeth  the  subject  is  clouded  in  obscurity.  From  the  nature  of  the  con- 
ditions it  is  difficult  to  secure  definite  information.  Dr.  Younger  holds 
to  the  belief  that  the  pericementum  becomes  revivified  and  hence  the 
attachment  is  almost  physiological.  Others  maintain  that  the  filling 
of  the  space  around  the  root  of  the  tooth  with  compact  bone  tissue 
is  sufficient  to  account  for  the  retention  of  the  tooth.  In  the  appear- 
ance of  planted  teeth  which  have  failed  there  should  be  found  the  best 
illustrations  of  the  causes  of  success.  It  is  probable  that  a  planted 
tooth,  by  reason  of  the  absence  of  the  cushion  formed  by  the  living 
pericementum,  causes  more  or  less  irritation  in  the  socket;  that  this 
irritation  leads  to  resorption  of  the  root ;  that  in  this  resorption  and 
the  subsequent  filling  up  of  these  resorbed  surfaces  are  found  reasons 
for  the  success  of  the  operation.      Fig.  574,  at  a,  a,  shows  how  a  par- 


648 


PLANTATIOy  OF  TEETH. 


Fui.  574. 


An  implanted  tooth  in 
situ :  a,  a,  excavations  of 
the  cementura  due  to  re- 
sorptive  process. 


tially  rc.«orho(]  root  may  ho  rctaiiiod  in  placo.  The  lenjjth  of  time 
during  wliicli  a  planted  tooth  is  retained  depends  entirely  upon  the 
rapidity  of  the  resorptivc  jiroccss  and  the  activ- 
ity of  the  tissues  in  maintaining  a  healtiiy  con- 
dition. Jieplanted  and  transplanted  teeth  have 
been  known  to  do  good  service  for  from  twenty 
to  forty  years.  The  time  of  the  observation  as 
to  implanted  teeth  is  shorter,  the  oldest  cases 
Ix'ing  less  than  twenty  years  old.  In  the  writer's 
ob.servations,  extending  over  a  period  of  nearly 
eighteen  years,  a  number  of  teeth  have  been  noted 
which  have  been  retained  successfully  for  ten 
years ;  how  nuich  longer  they  will  remain  ser- 
viceable, and  what  percentage  of  success  will 
attend  later  cases,  will  require  further  time  to 
determine.  Dr.  Younger  has  had  successfully  implanted  teeth  under 
observation,  at  last  report,  for  eleven  years. 

Precautions. — There  is  no  special  danger  connected  with  any  of  the 
operations  described  in  this  chapter,  provided  the  usual  antiseptic  ])re- 
cautions  are  observed  and  dangerous  anesthetics  avoided.  Aside  from 
these,  during  the  operation  of  replantation  and  transplantation  no 
special  skill  is  necessary  ;  certain  precautions  are,  however,  essential. 
Inasmuch  as  implantation  is  an  essentially  esthetic  operation,  it  should 
be  borne  in  mind  that  it  is  confined  principally  to  the  ten  anterior  teeth, 
and  that  it  is  more  frequently  performed  in  the  upper  jaw  than  in  the 
lower.  The  territory  involved  is  therefore  limited.  The  operator  who 
contemplates  forming  in  this  territory  a  socket  for  the  recejition  of  the 
root  of  a  tooth  should  be  intimately  acquainted  with  the  anatomical 
and  histological  relationships  of  the  various  parts. 

In  the  first  place  it  should  be  remembered  that  where  alveolar 
resorption  has  taken  place,  the  relative  depth  of  bone  is  considerably 
less  than  where  a  tooth  is  still  in  situ  and  surrounded  by  the  normal 
alveolar  process.  The  operator  must  therefore  not  penetrate  deeper 
into  the  bone  than  the  original  depth  of  the  socket  may  have  been. 
Indeed,  it  is  not  as  a  rule  necessary  to  penetrate  so  far. 

In  the  upper  jaw  the  principal  danger  in  making  a  socket  for  the 
reception  of  central  incisors  lies  in  the  proximity,  posteriorly,  of  the 
anterior  palatine  nerve,  artery,  and  vein,  which  have  their  exit  from  the 
bone  through  its  foramen,  often  near  the  roots  of  these  teeth.  With 
the  lateral  incis(jr  the  principal  precaution  necessary  is  the  preservation 
of  the  labial  plate  of  the  alveolus.  If  the  lost  tooth  has  been  absent 
for  some  time,  and  much  resorption  has  taken  place,  it  is  sometimes  im- 
possible to  drill  a  socket  so  that  the  tooth  has  a  proper  direction  and 


PREPARATION  OF  TEETH  FOR   PLANTATION.  649 

prominence  in  the  arch,  and  yet  be  able  to  secure  a  bone  covering  for 
its  labial  surface.  As  a  rule  there  is  sufficient  process  in  the  canine 
region  to  enable  the  operator  to  secure  all  the  attachment  desirable. 
The  bicuspid  and  molar  regions  present  the  danger  of  perforation  of  the 
floor  of  the  maxillary  sinus.  This  is  liable  to  happen  anywhere  from 
the  first  bicuspid  to  the  second  mol^r.  Extreme  caution  should  be  ex- 
ercised to  avoid  it.  In  two  instances  in  practice  the  perforation  was  fol- 
lowed by  no  unpleasant  complications.  Care  was  taken  not  to  infect  the 
sinus,  the  teeth  were  implanted  in  the  usual  manner,  and  the  cases  re- 
sulted successfully.  Subsequently  one  of  these  teeth  was  lost,  but  dur- 
ing the  process  of  root  attachment  or  encystment  the  perforation  into 
the  sinus  was  closed. 

In  the  lower  jaw  the  principal  difficulties  encountered  are  the  follow- 
ing :  In  the  incisive  region  there  is  a  deficiency  of  alveolar  process,  and 
hence  much  difficulty  is  encountered,  at  times,  in  securing  a  sufficiently 
deep  bony  socket.  At  the  location  of  the  canine  tooth  the  lower  jaw 
becomes  broader  and  there  is  usually  sufficient  room  to  enable  the 
making  of  a  good  socket.  In  the  premolar  region  the  principal  pre- 
caution necessary  is  in  regard  to  the  mental  foramen.  It  must  be  borne 
in  mind  that  normally  the  exit  of  the  nerves  and  vessels  at  this  point 
is  directly  below  the  second  bicuspid  tooth  and  that  when  resorption  of 
the  alveolar  process  has  taken  place  this  foramen  is  often  near  the  upper 
border  of  the  jaw.  From  this  point  posteriorly  implantations  are  rarely 
performed,  and  when  done  the  principal  precaution  must  be  in  regard 
to  the  inferior  dental  canal,  which  is  near  the  surface  if  much  resorp- 
tion has  taken  place. 

Artificial  Crowns. — The  precautions  necessary  in  the  selection  of 
a  tooth  for  transplantation  or  implantation  have  been  noted,  and  it 
might  be  proper  at  this  time  to  describe  the  prepara- 
tion of  a  root  with  an  artificial  crown,  presuming  that 
it  is  only  in  rare  instances  that  a  suitable  entire 
natural  tooth  can  be  obtained.  Attention  was  called 
to  the  necessity  of  securing  asepsis  of  the  root,  and 
the  filling  of  the  root-canals  has  been  described.  The 
most  suitable  form  of  crown  has  been  found  to  be  the 
Logan,   which   is   e-round  to   suit  the    occlusion  and      Natural  root  with 

°       '  o  ^  artiticial  crown. 

cemented  into  the  root  canal  without  much  regard  as 
to  a  careful  fit  at  the  cervix  of  the  crown  to  the  root.  After  the 
cement  has  hardened,  the  margin  between  the  root  and  crown  is  pre- 
pared with  engine  burs,  and  a  filling  of  gold  introduced,  making  a 
circle  around  the  tooth.  When  this  is  polished  down  there  is  a 
perfect  gold  filling  level  with  the  root  and  crown,  which  is  preferable 
to  a  soldered  band.     (See  Fig.   575.) 


650  PLANTATION  OF  TEETH. 

General,   Considerations. 

Asepsis. — The  ojx'rations  ik'st'ril)t'(l  in  this  chaptor  must  al\vuy.s  be 
performed  under  perfeet  aseptic  conditions  ;  that  is,  the  hands  and 
person,  instruments  and  other  accessories,  the  tooth  about  to  be  planted, 
and  the  field  of  surj2;ical  operation,  must  be  maintained  in  a  clean, 
aseptic  condition. 

Any  of  the  usual,  accepted  methods  can  be  resorted  to.  Asa  rule, 
however,  the  drujjs  selected  for  this  purpose  should  not  be  of  an  irri- 
tating nature.  For  the  hanils  and  person,  pure  soap  followed  by  a  5 
per  cent,  solution  of  carbolic  acid  is  sufficient.  The  instruments  and 
other  accessories  can  be  kept  free  from  inoculating  bacteria  by  the  use 
of  pyrozone,  formalin,  eutliymol,  or  a  5  per  cent,  solution  of  ('arl)olic  acid. 
The  use  of  bichlorid  of  mercury  in  the  proportion  of  1  ])art  to  2000  of 
water  is  also  permissible,  although  it  is  not  as  advisable  on  account  of 
its  irritating  nature.  The  sterilization  of  the  tooth  about  to  be  planted 
diflPers  according  to  circumstances.  A  tooth  whose  source  is  unknown, 
and  which  has  been  kept  in  a  dry  state  for  a  long  period,  will  not  be 
beuetited  by  being  placed  into  an  antiseptic  solution  until  just  prior  to 
the  time  when  it  is  to  be  used.  Hence  dry  teeth  can  be  kept  in  any 
clean  box  covered  with  clean  cotton  until  they  are  ready  for  use.  After 
the  necessary  preparation  hereinafter  described,  the  dry  tooth  should  be 
placed  in  a  solution  of  glycerol  and  carbolic  acid  (about  5  })er  cent,  of 
the  latter),  and  just  before  using,  it  can  be  placed  in  a  pyrozone  solu- 
tion or  in  a  solution  of  carbolic  acid  and  water.  Freshly  extracted  teeth 
should,  of  course,  have  their  pulp  chambers  and  root  canals  cleansed 
and  hermetically  sealed,  and  then  be  placed  at  once  in  fluid,  preferably 
in  glycerol  to  which  a  few  drops  of  carbolic  acid  have  been  added. 
Teeth  and  roots  so  treated  have  been  preserved  for  eight  years. 

The  field  of  operation  may  be  quickly  sterilized  and  cleansed  of 
adhering  mucus  by  mopping  the  surface  with  a  ball  of  cotton  saturated 
with  hydrogen  dioxid  3  per  cent,  solution  just  ])revious  to  operating. 

It  is,  of  course,  of  exceeding  importance  that  the  socket  into  which 
a  tooth  is  about  to  be  planted  shall  be  free  from  disease  germs  or 
bacteria.  As  a  general  rule  flowing  blood  is  the  best  of  antiseptics, 
washing  away  any  bacteria  which  may  become  lodged  from  external 
sources,  hence  so  long  as  a  socket  is  constantly  being  filled  with  flow- 
ing blood  during  an  operation,  but  little  further  care  need  be  bestowed 
upon  it.  As  a  general  rule  the  socket  and  the  tissues  surrounding  it 
will  react  more  quickly  after  operation  the  less  the  medication  has  been  ; 
hence  the  very  slightest  and  mildest  of  antiseptics  are  indicated.  Zinc 
chlorid  2  to  5  grains  to  the  ounce  of  lukewarm  water,  hydrogen  dioxid 
3  per  cent.,  or  the  5  per  cent,  solution  of  carbolic  acid  in  lukewarm 
water,  give  most  satisfactory  results.  These  solutions  will  be  found 
quite  sufficient  to  maintain   the  field  of  surgical  operation  aseptic. 


GENERAL  CONSIDERATIONS.  651 

Anesthesia. — For  the  purpose  of  allaying  pain,  the  use  of  anes- 
thetics is  justified  when  imperatively  demanded,  but  unfortunately,  in 
the  plantation  of  teeth  the  benefits  derived  are  frequently  outweighed 
by  the  disadvantages  accruing  from  their  use. 

Anesthetics  are  either  general  or  local.  An  operator  would  scarcely 
be  justified  in  assuming  the  risks  attendant  upon  the  use  of  chloroform, 
ethylic  ether,  ethyl  bromid,  or  any  of  the  combinations  in  which  these 
anesthetics  are  administered.  Nitrous  oxid  would,  in  the  majority  of 
instances,  be  contra-indicated  by  reason  of  the  shortness  of  the  period 
of  anesthesia  which  it  induces. 

There  do  not  appear  to  be  any  records  of  satisfactory  results  with 
hypnosis.  That  field  is  open  to  the  intelligent  investigator  whose 
inclinations  lie  in  that  direction.  Local  anesthesia,  therefore,  is  the 
means  generally  employed.  The  use  of  cataphoresis  with  local  anes- 
thetics has  not  as  yet  been  satisfactory  for  this  purpose. 

The  method  adopted  has  usually  been  confined  to  the  injection  or 
other  introduction  of  cocain,  the  dose  being  variable,  but  usually  about 
5  to  15  minims  of  a  4  per  cent,  solution  of  the  hydrochlorid.  A  seri- 
ous objection  has  been  noted  to  injection  through  the  gum,  viz.  that 
more  or  less  sloughing  or  destruction  of  the  tissues  may  result,  and  this 
is  very  unfavorable  for  subsequent  success.  In  replantation  or  trans- 
plantation, sufficient  anesthesia  is  often  obtained  from  the  wash  used  in 
cleansing  the  socket ;  but  in  implantation  the  formation  of  the  new 
socket  is  often  an  exceedingly  painful  operation,  and  in  these  cases 
good  results  may  be  had  by  dipping  the  instrument  with  which  the 
socket  is  being  made,  into  crystals  of  cocain,  and  thus  by  the  friction 
of  the  instrument  rubbing  it  into  the  parts  that  are  being  operated 
upon. 

The  subject  of  anesthesia  may  be  dismissed  with  the  sole  injunction 
that  its  use  should  be  resorted  to  only  in  those  instances  where  it  is 
absolutely  necessary.  The  majority  of  the  cases  of  plantation  are  per- 
formed with  no  more  pain  than  is  inflicted  in  filling  operations. 

The  same  care  should  be  given  to  the  retention  of  transplanted 
teeth  as  is  given  to  the  retention  of  replanted  teeth.  Teeth  thus 
carefully  transplanted,  in  individuals  of  good  health,  often  remain  as 
useful  members  for  a  number  of  years.  In  the  past  insufficient  atten- 
tion has  been  given  to  asepsis,  and  this,  coupled  with  the  fact  that  the 
root  had  not  always  been  properly  filled,  has  not  resulted  in  as  much 
success  as  is  attained  with  present  methods,  and  yet  transplanted  teeth 
are  known  to  have  remained  in  a  healthy  and  serviceable  condition 
for  from  twenty  to  fi)rty  years. 


652  PLANTATION  OF  TEETH. 

The  Operation  of  Implantation. 

Implantation,  in  order  to  yield  the  best  results,  should  be  confined 
to  moutiis  which  are  hal)itiially  clean  and  free  from  disease,  and  to  a 
part  of  the  individual's  life  diu'ing  which  the  power  of  the  developed 
mental  processes  is  not  impaired.  Unclean  personal  habits,  the  ex- 
cessive use  of  stimidants,  and  occuj)ations  callin»j  for  an  unusual  ex- 
penditure of  nerve  force  are  unfavorable.  A  suitable  case  having  been 
selected,  an  impression  of  the  space  and  of  the  teeth  adjoining  it  is 
taken.  A  plaster  cast  is  made,  the  proper-sized  socket  drilled  therein, 
the  tooth  is  selected  and  prepared,  either  with  or  without  an  artificial 
crown  in  the  manner  previously  described,  the  occlusion  is  adjusted, 
and  a  retention  cap  is  made.  These  preliminaries  having  been  satis- 
factorily accomplished  the  case  is  ready  for  the  operation.  Under  the 
heading  of  General  Considerations  the  question  of  anesthesia  has  been 
already  treated. 

The  first  step  in  the  operation  is  the  making  of  an  incision  through 
the  gum  tissue.  A  number  of  different  kinds  of  incisions  have  been 
recommended  by  different  operators,  nearly  all  of  them  looking  toward 
the  preservation  of  the  largest  amount  of  gum  tissue.  Some  recom- 
mend a  crucial  incision  X,  turning  back  the  four  corners  of  the  gum 
tissue.  Others  have  recommended  an  incision  in  the  shape  of  the  letter 
H,  turning  back  the  two  flaps  thus  made. 

The  principal  objection  to  all  of  the  incisions  recommended  lies  in 
the  fact  that  they  all  look  toward  the  preservation  of  the  gum  tissue 
equally  for  the  labial  and  lingual  surfaces  ;  while,  as  a  matter  of  fact,  if 
proper  provision  is  made  for  the  protection  of  the  cervical  line  on  the 
labial  surface,  the  lingual  surface  will  take  care  of  itself,  for  it  will  be 
noticed  in  cutting  through  the  gum  tissue  that  it  is  much  thinner  where 
it  reflects  over  the  alveolar  border  upon  its  labial  aspect  than  upon  its 
lingual.  Hence,"  frequently,  if  no  attention  whatever  has  been  paid  to 
the  retention  of  gum  tissue  on  the  lingual  surface,  the  neck  of  the 
tooth  will  nevertheless  be  sufficiently  protected. 

Fig.  576. 


Incision  In  gum  for  implantation. 


Another  serious  objection  to  an  incision  which  leaves  two  or  more 
points  or  margins  to  be  preserved,  is  that  the  tenacity  of  the  gum  tissue 


THE  OPERATION  OF  IMPLANTATION. 


653 


Fig.  577. 


n 


Chisels. 


Fig.  578. 


makes  it  utterly  impossible  to  preserve  these  various  flaps  and  projec- 
tions intact  from  the  cutting  instruments. 

The  writer^s  method  consists  in  an  incision  resulting  in  one  flap, 
with  a  view  of  protecting  the  labial  surface  of  the  tooth  to 
be  implanted,  and  of  preserving  this  single  flap  from  in- 
jury during  the  progress  of  the  operation.  A  combina- 
tion, or  rather  a  modification,  of  the  most  suitable  incis- 
ions recommended  is  therefore  the  one  shown  in  Fig.  576. 
This  incision  is  made  with  ordinary  chisels  as  shown 
in  Fig.  577,  cutting  with  the  chisel  to  and 
including  the  periosteum,  lifting  it  for- 
ward and  holding  it  out  of  the  way  of 
the  operator  by  means  of  an  instrument 
similar  to  the  one  shown  in  Fig:.  578. 

The  operation  thus  far  is  usually  sim- 
ple and  as  a  general  rule  not  very  pain- 
ful. The  drilling  of  the  socket  varies 
with  different  individuals  according  to 
the  density  of  the  bone,  the  length  of 
time  that  the  tooth  has  been  out,  etc. 
In  some  instances  the  reamer  or  trephine  or  knife  pro- 
gresses rapidly,  while  in  others  progress  is  very  slow,  or 
sometimes  variable  as  the  instrument  enters  into  medul- 
lary spaces  or  passes  through  the  more  or  less  dense  parti- 
tions which  divide  these  medullary  spaces  from  each  other. 
The  operator  will  determine  during  the  operation,  by 
the  progress  he  is  making  with  different  instruments, 
which  are  the  best  to  use.  In  some  instances  the  entire 
socket  can  be  made  with  an  ordinary  engine  bur,  while 
in  others  the  strongest  instruments  especially  designed  for 
implantation  are  none  too  strong.  In  some  instances  an 
instrument  which  clears  itself  well  during  one  operation 
clogs  annoyingly  during  another.  It  is  desirable  to  de- 
scribe at  this  point  the  various  useful  instruments  which 
have  been  designed  and  are  now  upon  the  market.  While 
all  of  them  are  not  necessary,  some  one  or  more  of  each 
class  are  indispensable.  The  trephines  of  Dr.  Younger, 
of  San  Francisco,  which  have  been  improved  by  Dr.  W. 
W.  Walker  of  New  York,  have  (as  shown  in  Fig.  579),  a 
set-screw  collar,  also  shown  detached,  which  slides  on  the 
shank  and  is  first  fixed  by  a  set-scrcAV  as  a  gauge  of  the 
length  of  the  tooth  root.  As  will  be  noticed  the  trephines 
cut  only  on  the  edge,  and  hence  they  do  not  entirely  clear  themselves  ; 


Instrument  for 
holding  flap 
during  the 
operation. 


6o4 


VLASTATloy  OF  TKEril. 


the  reamiTs  doscriheil  «>n  a  .succeeding  page  arc  then  u.sed  tu  remove  the 
core  and  enlarge  the  socket. 


Fk;.  579. 

o  o  OOO 

nm 


Fig.  580. 


u 

1       2       .3       4       .-> 

Younger-Walker  trephines. 


Rollins'  spiral 
knives. 


The  .^pirnl  kuive.s  (Fig.  580)  devised  hy  Dr.  AV.  H.  Rollins  of 
Boston  are  in  many  cases  very  useful. 

They  are  also  open  to  the  ol))eetion  of  clogging.  As  an  improve- 
ment upon  these  the  spiral  crih  knife  shown  in  Fig.  581  has  the 
advantage  of  permitting  the  core  to  pass  within  it. 


Fig.  581. 


Fig.  582. 


Ottofy  spiral 
crib  knife. 


■J 


J 


Two  forms  of  Crycr's 
spiral  osteotome. 


Fig.  583. 


Ottolengui's  reamers. 


Dr.  E.  Ottolengui,  of  Xew  York,  has  devised  a  .set  of  reamers  (Fig. 
588).  There  are  nine  leaves  to  each  reamer  and  each  leaf  is  divided 
into  five  teeth.  Three  of  the  leaves  reach  the  a])ex  of  the  cone  point 
and  thus  allow  a  more  ra])i(l  forward  drilling  into  the  bone.  A  sliding 
collar  forms  a  gauge  to  indicate  the  proper  depth  to  drill. 


THE  OPERATION  OF  IMPLANTATION. 


655 


The  reamers  designed  by  Dr.  Younger,  illustrated  in  Fig.  584,  are 
also  very  suitable  for  this  purpose.  Dr.  Cryer's  spiral  osteotome — two 
forms  of  which  are  shown  in  Fig.  582,  one  with  dentate  edges,  the  other 
without — is  an  admirable  instrument  for  forming  the  artificial  socket. 

When  it  is  necessary  to  deepen  or  alter  the  shape  of  the  socket,  it  is 
done  very  simply  with  either  the  ordinary  burs  of  the  dental  engine  or, 
what  is  preferable,  a  bur  with  a  long  shank  such  as  shown  in  the 
accompanying  illustration  (Fig.  585). 


Fig.  585. 


Fig.  584. 


12      3 

Dr.  Younger's  reamers. 


12        3       4 
Engine  burs  with  long  shank. 


The  following  are  to  be  recommended  :  Nos.  1  and  3  of  the  Walker- 
Younger  trephines,  Nos.  1  and  3  of  the  Younger  reamers,  Nos.  1  and 
2  of  the  Rollins  spiral  knives,  Nos.  1  and  2  of  the  Ottofy  spiral  crib 
knives,  and  Nos.  1,  3,  and  4  of  the  Ottolengui  reamers  and  Cryer's 
osteotome. 

During  the  progress  of  the  drilling  of  the  socket,  the  tooth  should 
be  frequently  inserted  until  a  proper  adjustment  has  been  secured. 
Occasionally  these  teeth  can  be  implanted  and  so  perfectly  fitted  that  it 
is  almost  impossible  to  remove  them  with  the  unaided  fingers  ;  while  at 
times  the  bone  is  so  cancellated  and  the  tissues  so  flabby  that  a  socket,  no 
matter  how  carefully  drilled,  will  not  retain  the  tooth  in  place.  Nothing 
is  gained  by  a  too  close  adjustment  of  the  root,  as  pressure  must  un- 
doubtedly be  exerted,  and  pressure  causes  resorption,  and  may  be  fol- 
lowed by  inflammation.  A  fair,  moderate  fitting  of  the  root  is  all 
that  should  be  aimed  at.  Just  before  the  final  adjustment  the  socket, 
gums,  tooth,  and  all  parts  contiguous  thereto,  should  be  placed  in  an 
aseptic  condition  and  the  cap  adjusted  in  the  manner  before  described. 
Though  the  tooth  may  be  adjusted  to  its  socket  so  that  immediately 
afterward  it  exhibits  much  firmness,  yet  in  a  few  days  subsequent  to 
the  operation  it  invariably  shows  less  rigidity  and  an  apparent  tendency 


656  PLAyTATIOy  OF  TEETH. 

to  loosening.  This  result  is  probably  due  to  the  resorption  of  those 
areas  of  contact  between  the  tooth  and  its  artificially  formed  alveolus 
where  the  greatest  amount  of  pressure  is  exerted.  The  period  of 
loosening  is  generally  quickly  followed  by  a  progressively  increasing 
firmness  and  immobility  of  the  tooth  caused  by  calcification  of  the 
exudate  thrown  out  by  the  walls  of  the  alveolus  in  the  process  of  repair 
of  the  surgical  injury  to  which  it  has  been  subjected  by  the  operation. 
Planted  teeth,  when  lost,  are  lost  as  a  rule  as  a  result  of  resorption  of 
their  roots.  The  process  seems  analogous  to  the  resorption  of  the 
roots  of  deciduous  teeth.  Present  records  seem  to  indicate  that  re- 
sorption of  the  roots  is  slowest  in  progress  in  replanted  teeth  ;  it  is 
more  rapid  in  transplanted  teeth,  and  most  rapid  in  implanted  teeth. 
Intelligent  observation  over  replantations  and  transplantations  extends 
from  twenty  to  forty  years.  The  observation  of  implanted  cases  extends 
at  this  writing  to  about  nineteen  years,  and  successful  cases  have  been 
under  observation  which  have  remained  in  the  mouth  over  twelve  years. 
The  writer  has  the  records  of  cases  which  have  remained  and  done  good 
service  for  the  same  length  of  time. 


CHAPTER    XXIII. 

MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

By  Claek   L.  Goddaed,  A.  M.,  D.  D.  S. 


Eruption. — The  first  operation  the  dentist  is  called  upon  to  perform 
for  the  deciduous  (temporary)  teeth  is  lancing  the  gums  as  an  aid  to 
eruption  of  those  organs.  This  is  not  necessary  in  normal  but  only 
in  pathological  cases.  Although  gum  tissue  in  its  normal  condition  is 
comparatively  insensitive,  Avhen  it  is  inflamed  it  is  exceedingly  tender. 

The  principal  source  of  pain,  however,  is  not  in  the  tissue  overlying, 
but  when  a  tooth,  bound  down  by  the  dense  gum  tissue  above  it,  by  its 
own  growth  presses  upon  the  formative  organ  below,  it  causes  pain 
which  in  many  cases  may  be  so  excessive  as  to  cause  reflex  disorders 
of  alarming  character. 

Dr.  J.  W.  White  ^  says  :  "  The  manifestation  of  functional  inharmony 
from  pathological  dentition  will  depend,  as  in  trouble  arising  from  any 
other  disturbing  cause,  upon  the  temperament  and  health  of  the  child, 
its  dietetic  management,  and  its  hygienic  surroundings.  In  some  cases 
there  is  a  gradual  development  of  biliary,  gastric,  enteric,  and  cerebral 
complications,  a  slow  but  steady  loss  of  vital  power,  with  no  efibrt  at 
recuperation  and  feeble  resistance  to  the  undermining  influences  which 
gradually  but  surely  wear  out  the  young  life. 

"  In  other  cases  the  indications  of  disturbance  of  function  are  mani- 
fested primarily  in  the  nervous  system  :  the  symptoms  are  all  charac- 
teristic of  acute  derangement  and  are  dangerous  from  their  violence 
and  uncontrollability.  High  fever,  vomiting,  choleraic  diarrhea,  men- 
ingitis, convulsions,  stupor  and  death  are  the  rapidly  succeeding 
phenomena.  Between  these  two  phases  there  is  every  conceivable 
grade  of  symptoms,  every  imaginable  complication." 

By  many,  as  an  objection  to  lancing  the  gums  it  has  been  urged  that, 
in  case  the  tooth  does  not  erupt  immediately,  cicatricial  tissue  is  formed 
over  it  which  will  bind  the  tooth  down  more  rigidly  than  before.  Cica- 
tricial tissue  is,  however,  of  a  lower  degree  of  organization  than  normal 
tissue,  and  is  more  easily  broken  down. 

'  Amer.  System  of  Dentistry,  vol.  iii.  p.  327. 
42  657 


658 


MANAGEMEXT  OF  THE  DECIDUOUS  TEKTII. 


Fig.  586. 


The  iiulioatioiis  for  interference  arc  not  so  much  local  as  general — 
the  fretfiilness,  inability  to  sleep,  and  other  symptoms  mentioned  by 
Dr.  White.  The  gum  tissue  over  tlie  erupting  tooth  may  or  may  not 
be  hijrhlv  inflamed,  but  tiie  absence  of  such  inflammation 
does  not  contraindieate  lancing.  In  fact  some  of  the 
gravest  svstemie  disturbances  occur  where  no  local  mani- 
festations are  evident. 

The  object  is  to  divide  the  gum  tissue  Nvliirh  l)inds 
down  the  tooth  and  to  allow  it  free  egress.  The  most 
suitable  instrument  is  shaped  like  that  shown  in  Fig.  591 
and  sometimes  used  for  lancing  around  teeth  before  ex- 
traction. It  should  be  held  like  a  pencil  in  writing,  so 
that  one  or  more  Hiigers  can  form  a  rest  and  guide. 

For  operating  on  the  lower  jaw  the  child  is  best  .seated 
in  the  laj)  of  the  operator  with  the  head  against  his  breast. 
Jiv  passing  the  left  arm  around  the  infant's  head  and  in- 
serting the  left  thumb  in  its  mouth  with  the  fingers  under 
the  chin,  the  lower  jaw  can  be  held  rigidly  while  the  right 
hand   pei'ibrms  the  o])enition. 

For  operating  on  the  np])er  jaw  it  is  best  to  lay  the  child 
across  on  the  nurse's  lap.  The  operator  takes  the  head  on 
or  between  his  knees,  opens  the  mouth  by  inserting  one  or 
more  fingers  of  the  left  hand,  and  holds  the  thumb  and 
forefinger  on  each  side  of  the  alveolar  ridge,  thus  prevent- 
ing injury  to  contiguous  parts  during  possible  struggles 
of  the  child. 

For  inv.imr^i  a  simple  longitudinal  incision  is  made,  a 
little  longer  than  the  cutting  edge  of  the  tooth.  The 
lancet  should  be  sharj),  so  as  to  easily  penetrate  to  the 
tooth.  No  harm  will  be  done  except  to  the  blade  of  the 
lancet.  F'or  the  canines  a  single  incision  is  good,  but  a 
crucial  incision  is  better.  Sometimes  lancing  is  nece.ssary 
for  the  canine  after  it  is  partially  erupted,  as  the  gum 
tissue,  pierced  by  the  point  only  of  the  tooth,  may  form  a 
dense  ring  around  this  point  and  interfere  with  furtlier 
eruption.  Tn  such  a  case  a  division  of  this  ring  in  two  or 
more  opposite  places  will  give  relief. 

For  the  mnfars  a  crucial  incision  is  best,  one  cut  ex- 
tending from  the  posterior  l)uccal  to  the  anterior  lingual 
cusp,  and  the  next  from  th(>  posterior  lingual  to  the  ante- 
rior l)uccal.  Sometimes  lancing  is  necessary  for  these 
teeth  after  jiarlial  erupti<»n.  After  the  ciisjis  have  pierced  the  gum, 
the  tooth   mav  be  held  back   bv  the  bands  of  tissue  in   the  sulci.      In 


Glim  lancet. 


ERUPTION  AND   DURATION.  659 

such  cases  divisiou  of  these  bands  in  the  same  direction  as  before  de- 
scribed for  an  unerupted  tooth  will  give  relief.  Sharp-pointed  carved 
scissors  are  well  adapted  to  this  latter  operation. 

Fig.  587  will  illustrate  the  direction  of  the  incisions  described.  The 
relief  afforded  is  generally  immediate.  In  one  case  a  child  who  had 
been  fretful  for  several  days,  and  who  had  not  slept  at  all  during  the 
day,  was  asleep  in  the  writer's  arms  within  five  minutes  after  the  ope- 
ration.    The  gum  tissue  is  not  very 

sensitive,    so    the    operation    is  often  ^^'  '^^'" 

painless.       The    little    sufferer    will  <^P  ■  A  -" 

often   recognize   the    relief    obtained  ^»/»ui 

and   point   to  other  portions  of  the  '^^^^% 

gums  for  further  relief. 


Duration    of  the    Deciduous       "-^^f^    <  '  as 

Teeth. — The    importance    of    filling  -^fe^^NirO^         1  ..j^.i^msif'-h 
cavities  in  the  children's  temporary           ""^^^^R-  ~X^ 

teeth   is   often   overlooked,   even    by                 ^'^^^^^^  ^ 

dentists  themselves,  as  these  teeth  are  Lines  of  incision  in  lancing:  a,  a,  over  the 

Jill,                    1               ,  molars  ;  h,  6,  over  the  canines  and  incisors 

supposed    to    be    lost    so    early    as    to  before  er^iption ;   ccc,  over  the  molars 

render    such    operations     unnecessary.  and  canines  after  partial  eruption  (J.  w. 

mi  •      •                       n                          •  1        1         .  White). 

Ihis  is  generally  true  with  the  in- 
cisors, is  less  true  with  the  canines,  while  the  molars  often  need  at- 
tention. Fig.  534  (see  Chapter  XXI.)  shows  the  relations  of  the 
deciduous  to  the  permanent  dentures  in  a  child  of  about  six  years 
of  age.  A  study  of  the  following  table  will  show  that  while  the 
incisors  are  superseded  early  by  their  successors  the  molars  are  in 
place  nearly  twice  as  long : 

Time  of  Eruption.  Loss.  Duration. 

Central  incisors 6-8  months.  6th-7th  year.         5i  to  Si  years. 

Lateral      7-9  "  7th-8th  "  "  "    "     " 

First  molars 14-16  "  9th-10th  "  7|  "    9     " 

(1  yr.   2  m.-l  yr.  4  m.) 

Canines 17-18  "  flnf.     8th-10th  " 

(IJyrs.)  ISup.  llth-12th  "  7     "   10   " 

Second  molars 18-24  "  12th-13th  "         10     "    11    " 

(1§  yrs.-2yrs.) 

The  temporary  molars  should  be  preserved  for  three  reasons : 

1st.  To  prevent  the  child  suffering  pain. 

2d.  To  allow  proper  mastication  of  food. 

This  latter  is  of  extreme  importance,  as  these  years  are  especially 
important  ones  in  the  child's  growth.  If  he  is  prevented  by  pain  from 
properly  masticating  his  food  it  will  not  be  assimilated,  and  a  habit  of 


660 


MAXAGEMEyr  OF  THE  DECIDUOUS  TEETH. 


swallowing;  food  without  masticating  may  be  continued  even  when  the 
permanent  teeth  have  erupted. 

3d.  To  preserve  the  fulness  of  the  areh  for  the  permanent  teeth. 

Early  loss  of  the  deciduous  second  molar  will  allow  the  first  per- 
manent molar  to  move  forward  and  occupy  room  that  should  be  pre- 
served for  the  premolars  (bicuspids).  Early  loss  of  the  first  temporary 
molar  will  allow  the  second  temporary  and  the  first  permanent  molar  to 
move  forward. 

The  crowns  of  the  temporary  molars  are  much  larp^er  than  the 
necks,  and  caries  of  the  approximal  surfaces  will  allow  them  to  crowd 
together  with  the  same  result.  Ap])roximal  fillings  inserted  should  be 
so  shaped  as  to  preserve  the  original  contour.  If  the  first  permanent 
molar  thus  moves  forward  of  its  natural  position  a  smaller  arch  is  left 
for  the  successional  teeth.  The  result  may  be  a  constricted  arch,  a 
pointed  arch,  upper  protrusion,  or  the  labial  displacement  of  the 
canines. 

Fig.  588.* 


Decalcification  of  tlu- 


nhiipiis  teoih.    The  numbers  indicate  years. 


Odontalgia. — The  first  visits  by  children  are  usually  for  the  relief 
of  "  toothache,"  and  may  occur  at  any  age  from  two  years  upward. 

The  first  treatment  of  most  children's  teeth  should  be  palliative. 
In  many  cases  a  fear  of  the  dentist  has  been  engendered,  which  it  should 
be  the  prime  object  to  remove.  Make  the  acquaintance  of  the  little 
patient  in  the  reception  room,  talking  perhaps  of  things  altogether 
foreign  to  the  case  in  hand,  and  distract  its  attention.  If  the  child  is 
very  timid  examine  the  teeth  Avhile  it  is  seated  in  an  ordinary  chair,  or 
in  its  parent's  laji,  and  apply  some  dressing  to  relieve  the  pain. 

In  the  operating  room  the  chair  should  be  adjusted  to  its  smallest 
size ;  a  special  child's  seat  may  be  used,  or  a  cushion  half  the  size  of  the 
chair  seat,  and  not  too  soft.  The  child's  head  should  be  made  comfort- 
able in  the  head-rest.  The  operator  should  not  let  the  child  detect  him 
in  an  endeavor  to  hide  instruments  ;  the  necessary  ones  may  be  shown 
to  him  if  they  arouse  his  curiosity,  and  their  purpose  explained. 

*  I'rof.  Pierce  in  Avier.  System  of  Dentistry,  vol.  iii.  p.  639. 


ODONTALGIA.  661 

On  account  of  the  difficulty  the  child  has  in  making  himself  under- 
stood, or  from  his  not  knowing  what  he  wishes  to  describe,  diagnosis  is 
difficult.  A  child  cannot  always  distinguish  just  where  pain  is  felt,  nor 
always  remember  its  exact  location.  In  most  cases  the  first  occurrence 
of  pain  is  during  mastication. 

It  is  necessary  to  ascertain  whether  pain  is  caused  by  an  erupting 
tooth,  a  nearly  exposed  pulp,  a  pulp  inflamed  and  dying,  a  putrescent 
pulp,  or  an  alveolar  abscess.  If  the  nearly  exposed  pulp  is  suspected, 
test  it  by  the  application  of  a  drop  of  cold  water.  Pain  during  masti- 
cation may  be  caused  by  thermal  changes,  by  pressure  of  food  in  the 
cavity,  or  by  pressure  on  a  tooth  whose  pericementum  is  inflamed. 

If  the  tooth  is  aching  while  the  child  is  in  the  chair,  syringe  out  the 
cavity  with  warm  water,  dry  it  with  bibulous  paper,  and  apply  a  pledget 
of  cotton  saturated  with  oil  of  cloves,  campho-phenique,  or  whatever 
has  been  found  effective  with  permanent  teeth.  Fletcher's  carbolized 
resin  ^  has  been  invaluable  for  this  purpose  in  the  writer's  practice. 
Applied  on  a  pellet  of  cotton  it  acts  as  an  anodyne,  and  the  resin 
hardens  in  the  cotton,  forming  with  it  a  temporary  stopping  which  will 
even  bear  the  force  of  mastication  for  a  few  days.  It  is  sometimes 
best  to  renew  this  dressing  a  few  times  before  attempting  a  more  per- 
manent treatment  or  filling. 

If  the  child  cannot  be  brought  to  the  office  again  within  a  few  days, 
let  the  parent  provide  himself  with  a  bottle  of  the  carbolized  resin  and 
an  inexpensive  pair  of  dressing  pliers.  Instruct  the  patient  how  to 
apply  the  cotton  dressing.  This  is  the  best  domestic  remedy  for  odon- 
talgia. Other  medicaments  may  be  used  by  the  parent,  such  as  oil  of 
cloves,  campho-phenique,  etc.,  but  their  effect  is  much  more  temporary. 
A  more  durable  dressing  may  be  made  by  mixing  zinc  oxid  and  car- 
bolized resin  to  the  consistence  of  putty  and  applying  it  in  the  cavity 
previously  dried.  It  hardens  under  moisture,  and  makes  a  stopping 
that  will  remain,  in  some  cases,  for  several  weeks. 

During  such  palliative  treatment,  sometimes  unavoidably  extended 
over  several  weeks  or  even  months,  the  child  is  growing  older,  is  gain- 
ing experience,  is  becoming  used  to  manipulation,  begins  to  recognize 
the  benefit  of  treatment  of  the  teeth — in  a  word,  is  being  trained  or 
educated  for  a  good  patient  for  whom  more  permanent  operations  may 
be  attempted. 

Prof.  li.  L.  Dunbar  says  :    "  As  a   domestic   palliative   always  at 

hand,  in  the  treatment  of  pulp  exposure  and  restricting  odontalgia,  use 

ammonia  on  cotton  :  its  repeated  use  will  devitalize  the  pulp,  at  the 

same  time  effecting  its  removal  by  saponification." 

'  Carbolic  acid, 
Resin  (colophony),  da.  ^j  ; 

Chloroform,  *Sss. 


662  managj::ml\\t  of  the  DECwrous  teeth. 

Treatment  with  Silver  Nitrate. 

IMoro  than  forty  years  ago  the  application  of  silver  nitrate  for 
arrostinu:  decay  was  advocated,  but  for  many  years  no  notice  was  taken 
of  it,  \\'itliin  the  last  five  years  it  has  been  advocated  again,  especially 
for  use  in  the  temporary  teeth.  The  fact  that  it  blackens  the  decaye'd 
surface  is  not  as  objectionable  as  with  permanent  teeth.  Dr.  Stebbins* 
advocated  the  use  of  a  solution  of  the  crystals  of  silver  nitrate  in  cari- 
ous cavities  in  temporary  teeth.  He  applies  it  by  means  of  a  small 
stick  inserted  in  a  socket  instrument  as  shown   in    Fig.   5H9.      INIanv 

Fui.  589. 


cases  will  need  no  further  treatment,  decay  being  completelv  arrested. 
Some  cases  will  need  secondary  treatment  after  a  few  months.  In 
many  cases  he  advises  filling  the  cavity  with  gutta-i)ercha  after  the 
apj)lication. 

Dr.  C.  N.  Peirce^  advises  saturating  pieces  of  blotting  pa])er  with 
40  per  cent,  solution  of  silver  nitrate,  and  keeping  these  on  hand  for 
use. 

Dr.  E.  C\  Kirk  advises  the  use  of  asbestos  felt  for  saturation  with 
the  solution  in  preference  to  blotting  paper  or  cotton.  He  savs  :'  "  The 
contact  of  silver  nitrate  with  vegetable  fiber  of  any  sort  involves  not 
only  a  destruction  of  the  fiber  but  also  of  the  silver  nitrate,  so  that  the 
preparation  in  a  short  time  loses  its  desirable  qualities."  He  advises 
that  the  asbestos  felt  be  heated  before  the  blowpipe  before  saturation, 
to  burn  out  any  organic  material  which  may  be  present. 

Dr.  A.  INI.  Holmes  ^  advises  its  use  as  follows  for  approximal  cavities  : 
"  C'\it  away  the  walls  to  a  V  shape,  and  with  a  j)iece  of  gutta-percha, 
softened  by  iieat,  of  the  pro]>er  size  to  fill  the  space,  bring  the  surface 
to  come  in  contact  witli  the  diseased  part  of  the  teetli,  into  contact  with 
the  powdered  crystals  of  silver  nitrate  and  carry  it  to  the  place  in  the 
tooth  or  teeth  prejiared  for  its  rece))tion,  packing  it  firmly  and  leav- 
ing it  there  to  be  worn  away  by  use  in  mastication.  When  that  takes 
place,  the  siu'faces  of  the  teeth  treated  will  be  found  black  and  hard, 
with  no  sensitiveness  to  the  touch  or  to  change  of  temperature,  and 
they  will  remain  so  indefinitely.      In  case  the  child  is  so  timid  as  to 

'  Fiilrrnnlioudl  Denial  Ji>iini(il,  ]S<)1,  p.  ('.til.  ^  /fc/f/^  189.3,  p.  152. 

*  Dental  Cosnin.",  189.S,  p.  HOT.  ♦  Ibid,  1892,  p.  982. 


FILLING  MATERIALS.  663 

prevent  this  course,  dry  the  cavity,  take  out  as  much  softened  dentin 
as  the  patient  will  permit,  carry  the  crystals  on  softened  gutta-percha 
into  the  cavity  and  pack  it,  leaving  it  until  such  time  as  desirable  to 
make  a  more  thorough  operation." 

In  the  writer's  opinion  it  is  better  to  open  approximal  cavities  from 
the  occlusal  surface  rather  than  make  V-shaped  spaces,  as  the  full 
diameter  of  the  teeth  should  be  left  to  preserve  the  fulness  of  the 
arch. 

Silver  nitrate  in  its  action  penetrates  but  a  short  distance. 

The  Character  op  the  Patient. 

The  conditions  of  operating  on  the  deciduous  teeth  vary  so  much 
from  those  pertaining  to  the  permanent  teeth  that  a  different  consid- 
eration must  be  taken  of  filling  materials. 

The  little  patients'  mouths  are  small.  They  are  often  too  young  to 
reason  with  or  to  understand  the  purpose  of  the  operation.  They  have 
been  too  often  frightened  by  thoughtless  remarks  of  their  elders  in 
speaking  of  their  dentist. 

Oftentimes  the  first  sitting  must  be  utilized  merely  to  make  the 
acquaintance  of  the  child,  perhaps  cleaning  the  teeth  a  little,  or  intro- 
ducing some  palliative  dressing  in  an  aching  tooth.  The  greatest  care 
should  be  taken  not  to  hurt  the  child.  After  it  has  gained  a  little 
experience  it  recognizes  the  benefit  of  the  treatment,  and  will  often 
submit  to  operations  that  older  patients  even  shrink  from. 

Filling  Materials. 

Gutta-percha. — Pink  base-plate  gutta-percha  is  a  most  valuable 
filling  material.  In  approximal  cavities  where  it  is  not  exposed  to 
wear  and  where  the  shape  of  the  cavity  is  such  as  to  retain  it,  it  is 
practically  indestructible.  In  occlusal  and  compound  cavities  in  which 
it  is  exposed  to  wear  it  has  wonderful  durability,  lasting  in  some  cases 
for  several  years. 

Directions  for  Use. — Cut  the  gutta-percha  in  small  pieces  and  place 
them  on  a  gutta-percha  warmer  (see  Fig.  279),  where  they  can  be  kept 
soft  but  not  heated  enough  to  injure  the  material.  The  instruments 
also  should  be  warmed  (see  Fig.   286). 

Occlusal  Cavities. — Cut  away  the  margins  of  thin  enamel  with 
suitably  shaped  chisels,  and  remove  the  decayed  and  softened  dentin 
with  scoop  and  hatchet  excavators.  Do  this  as  thoroughly  as  the 
patient  will  permit,  but  do  not  sacrifice  the  patient  to  thoroughness,  for 
the  thorough  removal  of  softened  dentin  is  not  as  essential  as  with  per- 
manent teeth,  because  the  gutta-percha  is,  by  mastication,  kept  in  such 


664  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

accurate  contact  with  all  the  walls  of  the  cavity  that  further  soften- 
ing will  go  on  very  slowly  if  at  all.  No  special  attention  need  be  paid 
to  the  form  of  the  cavity,  except  that  its  mouth  should  not  be  larger 
than  the  rest,  nor  should  any  parts  of  the  cavity  be  inaccessible  to  the 
filling  material.  After  excavating,  dry  the  cavity  with  bibulous  paper, 
and  apply  cam})ho-phenique,  oil  of  cloves,  or  carbolic  acid,  to  sterilize 
anv  softened  dentin  which  may  not  have  been  removed.  For  drying 
cavities,  prepare  paper  cylinders,  of  dilferent  sizes,  as  follows  :  Tear 
the  bibulous  paper  in  strips  from  half  an  inch  to  two  inches  in  width. 
Roll  or  twist  each  of  these  strips  into  a  rope,  but  not  too  tightly — just 
enough  to  retain  tlu;  shape.  Cut  these  ropes  into  cylinders  from  a 
quarter  to  half  an  inch  in  length.  Some  of  these  will  be  as  large 
around  as  a  lead  pencil  and  others  no  larger  than  the  lead  itself. 

Protect  the  tooth  from  moisture  as  well  as  possible.  For  lower 
cavities  fold  a  small  na])kin  diagonally  from  the  corner  till  it  is  about 
half  an  inch  wide.  Put  the  end  of  this  between  the  gum  of  the  upper 
canine  and  the  lip  and  extend  the  napkin  back  between  the  upper 
molars  and  the  cheek  beyond  the  last  tooth,  then  down  behind  the  last 
lower  molar,  and  ])ress  it  between  the  lower  teeth  and  tongue.  Tell 
tiie  j)atient  to  raise  the  tongue  as  it  is  applied,  then  to  lower  the  tongue 
and  hold  the  napkin  with  it.  The  part  of  the  napkin  between  the 
upper  teeth  and  the  cheek  will  cover  the  mouth  of  the  duct  of 
Steno,  and  prevent  or  absorb  the  flow  of  saliva.  It  is  better  to  cover 
the  mouth  of  this  duct  with  a  piece  of  spunk  about  half  an  inch  in 
diameter  before  applying  the  napkin.  The  folds  of  napkin  between 
the  lower  teeth  and  tongue  and  under  the  tongue  will  absorb  the  saliva 
from  the  submaxillary  glands.  This  part  of  the  napkin  can  be  held  in 
place  with  a  mouth  mirror  or  other  blunt  instrument,  by  the  operator 
or  assistant.  After  applying  the  napkin  use  a  large  bibulous  paper 
cylinder  to  absorb  the  moisture  from  the  tooth  to  be  filled  and  also 
from  contiguous  ones.  With  smaller  cylinders  or  pellets  dry  the  cavity. 
Apply  once  more  campho-phenique  or  other  medicament,  and  absorb 
the  excess. 

The  gutta-percha  having  been  meanwhile  warmed  and  softened, 
pick  up  a  small  piece  of  it  with  a  cold  round-pointed  instrument 
and  press  it  into  the  cavity.  If  the  cavity  is  not  large,  a  single 
piece  of  gutta-percha  of  a  diameter  less  than  that  of  the  cavity,  but 
longer  than  the  cavity  is  deep,  can  be  pressed  in  quickly  and  at  one 
movement.  For  medium-sized  cavities  select  a  piece  of  gutta-percha 
large  enough  to  cover  the  floor  of  the  cavity  and  press  it  into  place 
with  a  cold  instrument,  as  a  warm  instrument  might  drag  it  from  its 
place.  Add  similar  pieces,  pressing  each  one  to  the  place  in  which  it  is 
to  remain,  till  the  cavity  is  full.     If  at  any  time  the  gutta-percha  in  the 


FILLING  MATERIALS.  665 

cavity  becomes  so  hard  as  to  lose  its  plasticity,  apply  a  warm  instrument 
to  soften  the  surface,  so  that  the  next  piece  will  adhere  to  the  others. 
As  the  filling  nears  completion  select  a  small  piece  for  the  last,  just 
large  enough  to  complete  the  filling  and  no  more,  so  that  none  will 
have  to  be  trimmed  away,  for  in  trimming  the  surplus  away  the  filling 
may  be  drawn  from  contact  with  the  walls  of  the  cavity. 

In  filling  large  cavities  it  may  be  necessary  to  hold  the  first  piece  in 
position  with  another  instrument  till  sufficient  material  is  added  for  self- 
retention.  At  the  completion  of  the  filling  slight  pressure  with  a  warm 
instrument  should  be  made  in  such  a  manner  as  to  force  the  material 
against  all  the  margins  of  the  cavity. 

Approximal  Cavities. — Where  possible,  approximal  cavities 
should  be  opened  from  the  buccal  surfaces,  as  advised  by  Dr.  Bon- 
will,  as  in  such  cases  gutta-percha  fillings  will  not  be  exposed  to  the 
force  of  mastication.  This  plan  is  not  often  practicable  because  the 
patient  is  seldom  presented  till  the  cavity  has  become  visible  by  open- 
ing into  the  occlusal  surface  of  the  tooth.  In  such  cases  cut  away  the 
enamel  only  enough  to  give  access  to  the  cavity,  excavate  the  decayed 
dentin,  and  trim  the  buccal,  lingual,  and  cervical  walls  until  a  smooth, 
firm  margin  is  obtained. 

In  filling  such  a  cavity  use  small  pieces  of  softened  gutta-percha, 
pressing  each  piece  where  it  is  to  remain,  and  avoid  a  surplus.  Press 
the  gutta-percha  against  the  adjoining  tooth  as  if  it  were  a  matrix  or  a 
fourth  wall  of  the  cavity  and  let  it  remain.  It  is  useless  to  trim  it 
away  from  the  adjoining  tooth,  because  the  force  of  mastication  would 
soon  spread  the  filling  against  it  again. 

If  an  approximal  cavity  cannot  be  readily  shaped  so  that  it  will 
retain  the  gutta-percha,  it  may  be  packed  against  the  adjoining  tooth, 
as  if  it  were  an  occlusal  cavity.  It  will  prevent  decay,  especially  if  sil- 
ver nitrate  is  applied  as  described  on  page  668,  and  maybe  retained  till 
the  patient  is  older,  when  a  more  thorough  operation  may  be  performed. 

The  spreading  of  the  gutta-percha  by  the  force  of  mastication  will 
tend  to  separate  the  teeth — which  is  sometimes  an  advantage  ;  and  also 
to  press  upon  the  gum  in  the  interproximal  space — which  is  a  disad- 
vantage. In  filling  children's  teeth  we  cannot  always  reach  the  ideal, 
but  must  select  the  method  and  material  which  will  have  the  greatest 
advantage  with  the  least  disadvantage.  If  the  teeth  separate  so  much 
that  the  pressure  of  the  gutta-percha  upon  the  gum  tissue  becomes  a 
serious   annoyance,   some   other   material  must   be    substituted. 

To  prevent  the  impinging  of  the  gutta-percha  upon  the  gum  in  the 
interproximal  space,  Dr.  M.  W.  Hollingsworth  ^  has  invented  a  space 
^  Dental  Cosmos,  1896,  vol.  xxxviii.  p.  553. 


660 


MANAGEMEyr  OF  THE   DF.VIDVOVS   TEETH. 


guard,  consisting  of  a  concave  elliptical  j)iece  of"  metal  coated  on  the 
convex  surface  with  gutta-percha.  This  guard  is  to  bridge  over  the 
interproximal  space.  It  is  placed  in  jmsition  with  the  instrument 
shown  in  H,  Fig.  590,  which  is  Marnied  slightly,  so  that  the  point  can 


Fig.  o!>0. 


Fig.  591. 


enter  a  small  hole  in  the  guard  and  adhere  to  the  gutta-percha  on  the 
under  side,  as  shown  at  c.  The  guard  is  placed  in  the  cavities,  after 
warming  the  gutta-percha,  as  shown  in  Fig.  596,  and  thus  covers  the 
cervical  borders.  Gutta-percha  is  now  filled  in  over  the  guard  as  if 
the  two  cavities  formed  a  single  crown  cavity. 

Advantages  of  Gutta-percha. — It  is  easily  applied  to  the  cavity ;  it  is 
insoluble  ;  is  durable  even  when  nuisticated  uj)on  ;  is  a  non-conductor  of 
thermal  impulses  ;  the  filling  is  finished  as  soon  as  the  cavity  is  full ;  it 
spreads  under  the  force  of  mastication,  and  is  thus  kept  in  contact  with 
the  walls  of  a  cavity  ;  it  can  be  used  even  under  moisture. 

Disadvantages. — Gutta-percha  is  softer  than  other  filling  materials, 
and  hence  wears  away  more  ra])idly.  In  approximal  cavities  it  will 
spread  the  teeth  apart,  and  may  then  press  upon  and  irritate  the  gum. 

Dryness  of  the  cavity,  though  very  desirable,  is  not  absolutely  necessary. 

Advantages  of  Zinc  J^ho.sphate  Cement. — It  is  a  poor  conductor  of 
heat ;  it  with.stands  the  force  of  mastication  better  than  gutta-percha ; 
it  adheres  to  the  walls  of  the  cavity,  and  hence  will  remain  where  no 
other  material  can  ;  it  is  easily  applied ;  its  color  may  be  selected  to 
match  the  tooth. 

Ames'  copper  cement  seems  to  be  even  a  better  preservative  than  zinc 
cements  in  places  where  the  black  color  is  not  objectionable. 

Disadvantages. — Absolute  dryness  of  the  cavity  is  a  prerequisite  to 
its  success ;  it  must  be  kept  dry  for  several  minutes  after  it  is  inserted 
in  the  cavity.  Zinc  phosphate  cement  disintegrates  in  some  mouths 
much  more  rapidly  than  in  others.  If  placed  too  near  the  pulp  it  may 
by  chemical  irritation  devitalize  it. 


FILLING  MATERIALS.  667 

Application  of  the  Rubber  Dam. — AYhile  many  hesitate  to  attempt 
the  use  of  the  rubber  dam  with  children,  it  will  be  found  upon  trial  that 
most  of  them  will  submit  to  it  without  trouble,  and  many  will  prefer  it 
to  other  means  of  keeping  cavities  dry. 

Although  there  is  an  advantage  in  applying  the  rubber  dam  before 
excavating — because  dryness  makes  the  teeth  less  sensitive,  and  a  clearer 
view  of  the  cavity  is  obtained — still,  for  the  sake  of  not  tiring  the  little 
patients  by  too  long  restraint  in  one  position,  it  is  better  to  do  most  of 
the  excavating  before  its  application. 

The  small  size  of  the  necks  of  the  deciduous  teeth  compared  with 
that  of  the  crowns  renders  the  retention  of  the  rubber  dam  easier  than 
with  permanent  teeth.  Even  considering  the  smallness  of  the  patients' 
mouths,  the  application  of  the  rubber  dam  is  not  difficult  in  many 
cases. 

For  retaining  the  rubber  dam  on  the  second  molar  a  clamp  will 
sometimes  be  necessary,  but  for  the  other  deciduous  teeth  a  floss  silk 
ligature  will  be  sufficient.  Having  punched  holes  of  suitable  size 
through  the  rubber  dam,  apply  it  over  the  teeth  affected.  If  the  cavity 
is  in  the  occlusal  or  buccal  surface  only,  it  will  not  be  necessary  to 
apply  it  over  more  than  one  tooth,  but  if  the  cavity  is  in  the  approximal 
surface  it  will  be  necessary  to  apply  the  rubber  dam  over  two  or  some- 
times three  teeth,  or  even  more,  if  several  cavities  are  to  be  filled  at  one 
sitting. 

It  is  not  always  necessary  to  tie  a  ligature  around  the  neck  of  the 
tooth,  as  merely  passing  the  waxed  floss  silk  between  the  teeth  will 
often  force  the  rubber  around  the  neck  of  the  tooth  enough  to  retain  it 
even  above  an  approximal  cavity.  The  silk  may  then  be  removed  by 
drawing  the  end  through  between  the  teeth. 

With  a  thin  burnisher  or  spatula  turn  up  the  edge  of  the  rubber 
around  the  neck  of  the  tooth  toward  the  gum.  The  tendency  of  the 
rubber  then  will  be  to  slide  in  that  direction  and  not  off  over  the 
crown.  If  a  ligature  be  necessary  to  hold  the  rubber  above  the  edge  of 
an  approximal  cavity  tie  it  tightly  around  the  neck  of  the  tooth,  even 
forcing  it  toward  or  under  the  edge  of  the  gum  with  an  instrument  when 
necessary.  The  clamp  on  a  second  molar  may  often  be  dispensed  with 
after  a  ligature  is  applied,  unless  it  is  needed  to  hold  the  rubber  out  of 
the  operator's  way.  The  only  object  in  omitting  the  clamp  is  to  pre- 
vent pain  or  discomfort  to  the  child. 

If  a  simple  ligature  will  not  retain  the  rubber  on  a  second  molar 
before  the  first  permanent  molar  has  appeared,  its  efficiency  may  be 
greatly  increased  by  stringing  a  bead,  about  an  eighth  of  an  inch  or  less 
in  diameter,  on  the  thread  and  tying  a  simple  knot  in  it  so  that  the  bead 
will  be  in  about  the  middle  of  the  ligature.     Tie  the  ligature  around 


668  MANAGEMEST  OF  THE  DECIDUOUS  TEETH. 

the  tooth  so  that  the  head  will  lie  ajiainst  the  distal  surface  of  the 
second  molar  on  or  near  the  gum.  Tiiis  head  will  prevent  the  rubber 
slippinp;  off  the  tooth.  A  short  cylinder  of  bibulous  paper  can  be  tied 
in  the  ligature  and  applied  with  the  same  effect,  and  even  a  large  knot  in 
the  ligature  on  the  distal  surface  of  the  tooth  will  often  answer  the  purpose. 

The  corners  of  the  rubber  dam  should  be  held  out  of  the  way  by  a 
suitable  holder  extending  around  the  head.  The  lower  border  may  be 
held  out  of  the  ojierator's  way  by  small  weights,  hooked  in  the  edge. 

Drv  the  cavity  and  the  whole  tooth  or  teeth,  and  complete  the 
excavation. 

Filling-  Cavities  with  Cement. — As  cement  can  be  applied  easily 
in  undercuts  and  very  irregularly  shaped  cavities  it  is  not  necessary  to 
cut  awav  the  enamel  more  than  is  sufficient  to  enable  the  operator  to 
thoroughly  remove  the  disintegrated  dentin.  Even  the  thorough  re- 
moval of  the  latter  is  not  as  essential  for  a  cement  filling  as  for  other 
materials,  for,  if  the  edge  of  the  cavity  can  be  made  smooth  and  the 
softened  dentin  be  thoroughly  sterilized,  the  cement  will  hermetically 
seal  it  and  prevent  further  disintegration  until  it  is  worn  away  beyond 
the  sound  edges. 

The  operator  may  take  much  greater  risks  in  leaving  disintegrated 
dentin  than  with  ix'rnument  teeth,  for  the  object  is  simply  to  retain  the 
tooth  till  the  time  arrives  for  its  successor  to  appear. 

It  must  be  remembered  in  excavating  cavities  in  deciduous  teeth 
that  the  pulp  is  much  larger  in  proportion  to  the  size  of  the  crown  than 
in  permanent  teeth,  and  that  in  trying  to  make  undercuts  or  retaining 
grooves  deep  enough  to  retain  a  filling,  the  pulp  may  be  exposed — an 
accident  which  should  be  carefully  guarded  against,  for  the  pulp  has 
not  even  the  recuperative  power  possessed  by  the  pulp  of  a  permanent 
tooth  proper  treatment.  Moreover,  death  of  the  pulp  prevents  normal  re- 
sorption of  the  root  and  may  thus  cause  irregularity  of  the  permanent  teeth. 

For  most  cases  the  cement  should  be  mixed  as  thick  as  can  be  easily 
and  quickly  manipulated,  liut  if  the  pulp  is  nearly  exposed  the  cement 
should  be  used  so  thin  that  it  can  be  applied  without  pressure,  by 
flowing  it  over  the  floor  of  the  cavity.  Cement  mixed  moderately 
thin  will  adhere  better  to  the  walls  of  the  cavity  than  when  it  is  as 
thick  as  it  is  possible  to  apply  it.  The  thinner  the  cement,  the  longer 
time  it  will  take  to  harden,  but  the  thicker  it  is  mixed  the  more  dur- 
able it  will  be.  Do  not  keep  the  little  patient  in  a  constrained  posi- 
tion longer  than  necessary.  The  easier  the  first  operation  is  for  him 
the  more  readily  will  he  return  for  the  second. 

If  the  pulp  is  very  nearly  exposed  apply  Fletcher's  carbolized  resin 
over  the  floor  of  the  cavity.  For  this  purpose  remove  the  stopper  of 
the  bottle  till  by  evaporation  the  carbolized  resin  has  thickened  to  the 


FILLING  MATERIALS.  669 

consistence  of  molasses.  Dip  a  small  probe  in  the  thickened  mass,  so 
that  a  small  drop  will  adhere  to  the  end.  This  drop  may  be  then  con- 
veyed to  and  spread  over  the  floor  of  the  cavity.  This  will  prevent 
contact  of  the  cement  with  the  most  sensitive  dentin  and  lessen  the 
possibility  of  deleterious  action  on  the  pulp. 

Where  it  is  possible  to  apply  the  rubber  dam  and  excavate  thoroughly 
the  same  excellent  result  with  cement  may  be  expected  as  when  it  is 
used  in  permanent  teeth,  but  often  it  is  not  possible  to  operate  as 
thoroughly. 

By  applying  melted  paraffin^  or  sandarac  varnish  to  the  cement  the 
rubber  dam  may  be  removed  sooner  than  otherwise,  and  the  cement 
will  be  protected  from  moisture  by  the  coating  of  paraffin  or  varnish. 

As  paraffin  is  insoluble  in  any  agent  that  can  attack  it  in  the  mouth, 
the  more  it  is  absorbed  by  the  cement  the  longer  it  will  protect  it  from 
everything  but  wear ;  therefore,  do  not  be  content  to  merely  flow  the 
melted  paraffin  over  the  cement,  but  hold  a  heated  instrument  in  contact 
with  the  filling  and  keep  the  paraffin  melted  until  all  that  is  possible  is 
absorbed.  If  an  approxiraal  filling  has  been  inserted  pass  a  very  thin 
heated  spatula  between  the  cement  filling  and  the  adjoining  tooth  to 
make  sure  that  the  paraffin  covers  it  to  its  cervical  margin. 

When  the  rubber  dam  cannot  be  applied,  cement  may  still  be  used 
with  success  if  the  cavity  can  be  kept  dry  with  napkins  or  rolls  of  cotton 
or  spunk  until  it  is  inserted  and  quickly  covered  with  melted  paraffin. 

Deep  cavities  may  be  advantageously  lined  with  cement  and  protected 
with  paraffin  till  the  cement  is  hard,  when  the  paraffin  may  be  removed 
and  gutta-percha  or  amalgam  inserted. 

Occlusal  fillings  of  cement  can  be  kept  dry  by  aj^plying  temporary 
stopping  very  soft  as  soon  as  the  cement  is  put  in.  Gilbert's  is  excel- 
lent for  the  purpose,  as  it  adheres  to  the  cement.  Buccal  fillings,  some- 
times approximal,  may  be  protected  in  the  same  way.  A  thin  tempo- 
rary stopping  may  be  left  to  be  worn  away  by  occluding  teeth. 

Cavities  in  Incisors. — Decay  in  deciduous  incisors  is  much  more 
rare  than  in  the  other  teeth,  and  they  are  lost  so  early  in  child  life  that 
it  is  seldom  necessary  to  fill  them.  Zinc  phosphate  cement  is  the  best 
filling  material  for  these  teeth,  because  they  are  so  small  that  it  is  very 
difficult  to  shape  the  cavities  properly  for  retaining  other  materials. 

If  it  is  found  that  cement  disintegrates  rapidly  in  approximal  cavities, 
an  attempt  should  be  made  to  shape  them  so  as  to  retain  gutta-percha. 
The  first  filling  of  cement  may  have  removed  the  sensitiveness  suf- 
ficiently to  allow  deeper  excavating  at  a  subsequent  sitting,  or  there 
may  have  been  a  deposit  of  secondary  dentin,  thus  removing  the  pulp 
from  danger  of  exposure  in  properly  shaping  the  cavity. 

Amalgam. — While  amalgam  is  a  valuable  filling  material,  its  use 
^  Dr.  Bonwill's  sugorestion. 


(;7()  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

necessitatos  niiicli  j^ivatiT  care  in  the  jircparation  of  cavities  tliaii  is 
necessary  with  ^utta-poroha  or  cement,  for  it  ncitlicr  spreads  under 
mastication  like  the  former  nor  does  it  a<lhere  to  the  walls  of  a  cavity 
like  tile  latter.  The  si>ri"adiiiL^  of  ^utta-percha  will  stop  a  leak  that 
would  he  fatal  to  an  aiiialuani  (illiuu-,  and  cement  will  adhere  in  a  cav- 
ity from  which  amaluani  would  he  easily  dislodo-ed. 

Amal>2:am  should  i)c  used  when  the  decay  can  he  thoroutrhly  excava- 
ted and  the  cavitv  prepared  with  stronir  smooth  edt]:es,  and  j^ood  under- 
cuts or  retainin<r  irrooves.  As  amalgam  is  a  hetter  conductor  of  thermal 
impulses  than  either  of  the  materials  before  mentioned  it  will  n(»t  he 
tolerated  so  near  the  pul]),  hence  deep  cavities  must  he  lined  with  either 
^utta-percha  or  zinc  ])hosphate. 

The  large  size  of  the  pulj)  of  deciduo.us  teeth — (.n-eater  in  proportion 
than  that  of  the  permanent  teeth — must  not  he  forgotten  in  exca- 
vating, and  often  it  is  impossible  to  make  snital)le  retaining  grooves  for 
amalgam  without  cutting  dangerously  near  the  pulp,  especially  in  ap- 
proximal  cavities. 

The  preparation  of  occlusal  cavities  is  comparatively  simple,  as  the 
enamel  may  be  easily  cut  away  so  as  to  make  firm  edges,  slightly 
bevelled,  and   to  allow  thorough  excavation  of  softened  dentin. 

The  burring  engine  can  be  used  to  greater  advantage  with  children 
than  manv  Mould  suppose.  The  whirring  noise  often  distracts  their 
attention  from  a  slight  pain  they  might  otherwise  notice,  and  the  assur- 
ance that  the  work  can  be  done  more  (piickly  is  a  great  encouragement. 
In  ])reparing  approximal  cavities  for  anialgam  a  free  opening  should 
be  made  in  the  occlusal  surface  and  given  a  dovetail  shajK',  extending 
farther  upon  the  occlusal  surface  in  proj)ortion  to  the  size  of  the  cavity 
than  in  permanent  teeth,  because  more  reliance  must  be  placed  on  it  for 
retention  than  upon  lateral  grooves,  for  there  is  not  much  depth  of 
dentin  in  which  to  make  them.  The  cervi.  a!  border  of  the  cavity  must 
be  snio(»th  and  the  Hoor  at  right  angles  to  the  long  axis  of  the  tooth. 
The  lateral  walls  must  be  cut  smooth  and  bevelled,  and  may  he 
sli<rhtlv  arrooved.  If  the  cavitv  extends  below  the 
margin  of  the  gum  the  latter  should  be  crowded 
away  with  a  temj)orary  st<»])j>ing  or  l)y  packing  a 
tightlv  rolled  pledget  of  cotton  between  the  teeth 
and  relying  on   its  swelling. 

In  many  cases  it  is  ]>ossible  to  extend  an  ajiproxi- 

i'repared  (-.,  ii\  Mi-wiuL'     nial  cavitv  to  the  sulcus  and  make  a  stej)  anchui-age, 

bevelling    of     enamel  .  '  , 

edges,  A,A,  and  square     »»  i»  permanent  teeth. 

base  for  filling.  «.  While  the  application  of  a  rubber  dam  is  not  as 

essential  as  in  using  cement,  it  is  a  great  advantage,  for  it  renders  the 
proper  preparation  of  the  cavity  more  certain,  but  it  need  not  be  aj)plied 


EXPOSED  PULPS.  671 

till  the  cavity  is  nearly  prepared.  Its  use  is  more  often  necessary  with 
the  lower  teeth  than  with  the  upper. 

Amalgam  should  not  be  mixed  too  dry,  but  should  be  plastic  enough 
to  be  packed  easily  without  crumbling.  In  occlusal  cavities  introduce  a 
piece  half  as  large  as  the  cavity,  and  with  a  small  ball  burnisher  spread 
it  over  the  floor  of  the  cavity  toward  the  walls.  Introduce  other  smaller 
pieces  and  proceed  as  before  until  the  cavity  is  nearly  full.  Excess  of 
mercury  is  thus  forced  to  the  edges  of  the  cavity,  whence  it  can  be 
brushed  away  with  cotton  or  bibulous  paper. 

The  last  pieces  of  amalgam  should  be  "  wafered,"  as  recommended 
by  Prof.  J.  Foster  Flagg — that  is,  squeezed  in  chamois  skin  with  large 
flat-nosed  pliers  till  as  much  mercury  as  possible  is  pressed  out  (see 
Fig.  281).  This  leaves  the  amalgam  in  a  thin,  brittle  wafer,  too  hard 
for  ordinary  use.  Break  it  up  in  pieces  half  the  diameter  of  the  cavity. 
Press  one  of  these  in  the  middle  of  the  nearly  completed  filling.  It 
will  readily  absorb  the  excess  of  mercury  that  has  been  worked  to  the 
surface,  and  can  be  spread  toward  the  margins  with  a  round  burnisher. 
Other  pieces  can  be  burnished  on  till  the  filling  is  quite  hard. 

In  filling  approximal  cavities  the  same  plan  may  be  followed  if  a 
matrix  of  thin  steel  or  German  silver  be  used.  In  lieu  of  the  matrix 
a  very  thin  spatula  may  be  held  between  the  teeth. 

Whenever  possible,  fillings  in  deciduous  molars  should  be  contoured 
to  avoid  the  crowding  of  food  between  the  teeth  and  also  to  prevent  the 
first  permanent  molar  from  crowding  them  together  and  thus  taking  up 
room  which  will  be  needed  by  the  bicuspids. 

The  child  should  be  cautioned  against  masticating  too  soon  upon 
approximal  fillings,  though  no  caution  is  needed  in  case  of  occlusal  fill- 
ings hardened  by  the  "  wafering "  process. 

Tin  and  gold  are  excluded  from  the  list  of  desirable  filling  materials 
for  temporary  teeth,  not  because  they  are  not  good  filling  materials  but 
because  the  circumstances  are  such  that  they  cannot  be  used  to  advan- 
tage. Though  a  small  gold  filling  may  be  inserted  in  a  few  minutes  in 
an  occlusal  cavity,  the  insertion  of  a  large  gold  filling  would  be  inflict- 
ing a  needless  cruelty  on  a  child  on  account  of  the  length  of  time  it 
must  be  held  in  one  position. 

As  the  insertion  of  a  tin  filling  is  nearly  if  not  quite  as  difficult  and 
tedious  an  operation,  it  is  open  to  the  same  objection. 

Exposed  Pulps. 

On  account  of  the  difficulty  of  properly  capping  an  exposed  pulp  in 
a  deciduous  tooth,  the  operation  should  seldom  be  attempted.  It  is 
better  to  devitalize  the  pulp  and  remove  it. 

The  writer  has  found  the  following  formula  ^  an  excellent  one : 

^  Used  by  Dr.  E.  N.  Clarke  in  the  "fifties." 


672  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

^.  Acidi  arsenics), 
Morphiae  acetatis, 
Pulv.  opii,  da.  pars  ceq. 

Croosoti  q.  s.  to  make  paste. 

Why  opium  and  acetate  of  morphia  sht)uld  both  be  used  in  the  same 
prescription  is  not  clear,  as  their  properties  are  so  nearly  the  same,  but 
the  paste  has  been  satisfactory  in  devitalizing  pulps  with  no  pain,  or 
with  a  minimum  amount.     Other  formulas  may  be  equally  satisfactory. 

In  occlusal  cai-ifies  its  application  is  simple.  Excavate  the  softened 
dentin  as  thoroughly  as  possible  without  inflicting  pain,  using  spoon- 
shaped  excavators  to  ])revent  puncturing  the  pulp.  If  the  excavation 
can  be  carried  far  enough  to  apply  the  paste  directly  to  the  pulp  its 
action  will  be  more  rapid.  Dry  the  cavity,  apply  a  small  amount,  not 
larger  than  half  a  pinhead  in  size,  with  a  small  probe  and  cover  it  with 
a  pellet  of  cotton,  or  j)lace  in  the  cavity  a  small  pellet  of  cotton  one 
side  of  which  has  been  touched  to  the  paste.  Add  enough  pellets  of 
dry  cotton  to  fill  the  cavity,  tlien  aj)ply  a  drop  of  sandarac  varnish,  suf- 
ficient to  saturate  at  least  half  the  depth  of  cotton.  This  is  a  better 
plan  than  dipping  the  pellets  in  the  varnish  before  inserting,  because  an 
excess  of  the  latter  is  aj)t  to  come  in  contact  with  the  pulj)  and  cause 
pain,  or,  penetrating  between  the  paste  and  the  pulp,  may  render  the 
former  inoperative.  Tem])orary  stopi)ings  such  as  Gilbert's,  AVhite's,  or 
Fowler's  are  excellent  for  sealing  the  cavity,  but  take  a  little  more 
time  than  cotton  and  varnish.  Such  temporary  stopping  should  be  well 
softened  by  heat  to  prevent  })ressure  on  the  ])ulp  in  its  insertion.  A 
good  plan  is  to  warm  the  end  of  the  long  stick  of  stopping  and  press 
it  into  the  cavity,  using  the  remainder  of  the  stick  as  a  handle,  then 
remove  the  surplus  and  smooth  with  a  warm  instrument. 

In  approximal  cnvities  extending  near  or  under  the  margin,  the  gum 
should  be  protected,  before  applying  the  paste,  as  follows  : 

Make,  by  rolling  between  the  fingers,  a  cylinder  of  cotton  as  long 
as  the  width  of  the  tooth  and  about  the  size  of  the  lead  of  a  pencil. 
Saturate  it  with  sandarac  varnish  and  pack  it  between  the  teeth  upon 
the  gum,  extending  part  of  it  below  the  edge  of  the  cavity,  thus  sealing 
this  portion  of  the  cavity  and  reducing  it  nearly  to  the  form  of  an 
occlusal  cavity.  Paste  applied  in  an  approximal  cavity  so  protected 
cannot  flow  upon  the  gum  unless  too  great  a  quantity  has  been  used. 
The  paste  should  be  aj)plied  and  sealed  as  in  an  occlusal  cavity. 

"  Devitalizing  fiber  "  is  very  satisfactory  and  may  be  used  with  less 
fear  of  its  aifecting  the  gum  tissue. 

The  paste  may  be  allowed  to  remain  in  the  cavity  for  from  twelve 
to  forty-eight  hours.     The  possibility  of  the  dressing  being  dislodged,  so 


FILLING  PULP  CANALS.  673 

as  to  allow  the  paste  to  come  in  contact  with  the  gum  tissue,  should 
warn  one  to  have  the  patient  return  much  sooner  than  when  the  case 
is  an  occlusal  cavity  from  which  it  is  impossible  for  the  paste  to  escape. 

Much  has  been  said  about  the  danger  of  application  of  arsenic  in 
deciduous  teeth  when  the  roots  are  undergoing  resorption,  but  the 
writer  has  never  seen  any  bad  effects  from  such  use  ;  still  it  nuist  be 
admitted  that  the  ratio  of  danger  varies  with  the  degree  of  resorption 
of  the  root.  An  examination  of  Prof.  Peirce's  diagram  (Fig.  588)  will 
show  the  average  amount  of  resorption  at  different  ages,  and  enable 
one  to  discriminate.  The  writer  believes  that  the  sensitiveness  of  a 
deciduous  pulp  varies  inversely  with  the  amount  of  resorption  of  the 
root,  and  that  devitalization  is  called  for  in  very  few  cases  in  which 
there  is  danger  of  deleterious  action. 

Prof.  L.  L.  Dunbar  advises  the  use  of  aqua  ammonite  for  devitaliz- 
ing the  pulp  of  a  temporary  tooth,  by  applying  it  on  a  pledget  of  cotton 
in  the  cavity,  one  or  two  applications  being  sufficient  in  most  cases. 
This  plan  is  not  open  to  the  objections  urged  against  the  use  of  arsenous 
oxid. 

When  the  pulp  is  devitalized,  open  the  cavity  freely  into  the  pulp 
chamber  and  apply  on  cotton  a  solution  of  tannic  acid  in  glycerol. 
Leave  this  about  a  week,  by  which  time  the  pulp  tissue  will  have  be- 
come so  hardened  by  the  tannin  that  it  may  be  removed  much  more 
readily  than  without  such  treatment. 

The  application  of  mummifying  paste  is  advised  by  many,  after 
devitalization,  to  avoid  the  necessity  of  removing  the  pulp.  If  a  real 
mummifying  paste  can  be  found,  its  application  will  be  the  ideal 
treatment. 

Filling  Pulp  Canals. 

In  the  pulp  canals  apply  iodoform  paste  made  by  mixing  iodoform 
and  glycerol  to  such  a  consistence  that  it  can  be  readily  applied  on  a 
probe. 

Fill  the  pulp  chamber  with  "temporary  stopping"  or  gutta-percha, 
and  the  cavity  with  cement,  gutta-percha,  or  amalgam  according  to 
indications. 

If  the  tooth  be  very  frail,  fill  the  cavity  with  cement,  because,  owing 
to  its  adhesive  properties,  it  strengthens  the  tooth.  If  the  cavity  be 
approximal  and  it  is  desirable  to  wedge  the  teeth  apart,  use  pink  gutta- 
percha. 

If  the  walls  be  strong  and  some  time  will  elapse  before  the  natural 
exfoliation  of  the  tooth  will  occur,  fill  with  amalgam. 

If  absorption  of  the  roots  occurs,  the  iodoform  in  the  canals  will  not 

interfere. 
43 


()74  MANAGEMEyr  OF   THE   DKc/DrOUS   TEETH. 

Salol,  whieli  was  advocated  as  a  root  tilling  for  permanent  teeth  by 
Dr.  A.  E.  Maseort'  of  Paris,  France,  is  well  adapted  also  for  filling  the 
canals  of  deciduons  teeth.  "  It  is  a  white  crystalline  powder,  insolnble 
in  water  and  glycerol,  but  soluble  in  alcohol,  ether,  ehlorotbrni,  etc, ; 
fuses  at  40°  C.  but  crystallizes  quickly  again."  Melted  together,  salol 
and  aristol,  salol  and  iodoform,  or  salol  and  ])araftin,  become  liquid 
like  salol  alone.  After  a  pulp  canal  is  thoroughly  dried  the  salol  mav 
be  fu.sed  on  a  small  spatula  and  carried  to  the  canal,  into  which  it  will 
be  taken  by  capillary  attraction  or  a  broach  may  be  heated  and  in.serted 
in  the  salol.  A  small  (puintity  will  adhere  like  a  drop  of  liquid  and 
may  thus  he  carried  to  the  canal.  The  heated  broach  may  be  again 
introduced  in  the  canal  to  insure  thorough  application.  Dr.  Maseort 
uses  the  hy])odcrmic  syringe  with  a  small  needle  for  introducing  into 
the  canals.  It  will  crystallize  in  a  very  short  time,  making  a  solid  till- 
ing. Though  the  writer  has  not  had  much  experience  with  salol  as  a 
root  tilling,  he  is  so  far  well  pleased  with  the  rcstdt.  (See  Chapter 
XVII.) 

Alveolar    Abscess. 

The  treatment  should  be  the  same  as  with  the  jiermanent  teeth,  that 
is,  removal  of  the  cause — which  is,  almost  invariably,  a  decompo.sed 
pulp.  Even  with  a  decomposed  pulp  an  abscess  seldom  occurs  if  there 
be  any  opening  from  the  cavity  of  decay  to  the  l)ulp  chamber,  unless 
such  opening  has  become  stopped  by  some  foreign  substance. 

Make  a  free  opening  into  the  pulp  chamber  and  with  a  syringe 
wash  out  as  much  of  the  contents  as  possible.  Dry  the  chamber  and 
with  a  "minim  "  syringe  (sec  Chapter  XVII.,  Fig.  429),  or  drop  tube, 
apply  hydrogen  dioxid.  AVhile  capillary  attraction  will  carry  this 
into  a  dry  canal,  the  application  (»f  a  nerve  broach,  j)rcfcrably  platino- 
iridium,  will  serve  to  mix  it  thoroughly  with  the  contents  of  other 
canals,  and  increase  its  efficiency. 

If  a  fistulous  opening  has  formed  through  the  outer  alveolar  plate 
but  not  through  the  gum,  an  opening  should  be  made  through  the  latter 
with  a  sharp  lancet  about  five  minutes  after  the  application  of  4  per 
cent,  cocain  hydroehlorid  solution  on  a   wad  of  cotton. 

If  hydrogen  dioxid  can  be  fon.-ed  from  the  ptdj)  chamber  through 
the  root  canals  and  fistulous  opening,  the  accumulated  pus  will  be 
thoroughly  evacuated  and  the  cure  hastened.  As  a  rule,  however,  the 
abscess  disappears  after  the  cause  is  removed,  that  is,  the  putrescent  or 
decomposed  contents  of  the  pulp  chamber  and  canals. 

After  drying  the   jtnlj)  chamber  and   canals,  apply  iodoform   paste 

*  Dental  Cogmog,  1894,  p.  352. 


PROPHYLACTIC  TREATMENT.  67o 

therein  and  seal  the  cavity  for  a  few  days  with  temporary  stopping. 
When  the  inflammation  of  the  pericementum  has  disappeared  the  pulp 
chamber  and  canals  may  be  filled  as  before  directed. 

In  many  cases  the  inflammation  of  the  pericementum  will  be  so 
great,  or  in  popular  expression  the  tooth  so  "  sore "  to  the  touch, 
when  the  case  is  presented  that  at  the  first  sitting  nothing  more  can  be 
done  than  to  make  an  opening  into  the  pulp  chamber  to  allow  the  escape 
of  pus  or  gases  of  decomposition.  By  this  means  the  pain  will  be  re- 
lieved and  the  rest  of  the  manipulation  and  treatment  may  be  left  till 
the  inflammation  has  subsided. 


Prophylactic  Treatment. 

This  lies  more  in  the  hands  of  the  parent  than  of  the  practitioner, 
but  should  be  strongly  urged  by  the  latter  upon  the  former.  The  nurse 
or  parent  should  begin  early  to  clean  the  child's  teeth  by  means  of  a 
cloth  wrapped  around  the  finger.  If  the  teeth  cannot  be  kept  clean  in 
this  manner  a  small  brush  should  be  used,  especially  after  eruption  of 
the  molars.  Floss  silk  should  be  used  daily  between  the  teeth.  One 
end  of  the  silk  should  be  held  in  each  hand  in  such  a  manner  as  to  pass 
over  the  end  of  each  index  finger  and  be  made  taut  between  them. 
This  taut  part  can  be  pressed  down  between  the  teeth  and  passed  up  and 
down  against  the  api)roxinial  surface  of  each  tooth,  then  one  end  of  the 
thread  should  be  released  from  one  hand  and  pulled  through  the 
interdental  space  with  the  other. 

This  will  drag  out  any  particles  of  food  that  may  be  there,  and  is 
much  better  than  the  toothpick  for  the  purpose.  If  particles  of 
meat  or  other  food  have  lodged  so  firmly  that  the  plain  waxed  silk 
will  not  dislodge  them,  tie  a  single  knot  in  the  thread  and  pull  that 
through. 

This  cleansing  with  the  cloth,  brush,  and  silk  should  Ijc  done  before 
the  child  retires  at  night,  for  that  is  the  "  period  of  decay."  The  parts 
are  at  rest  longer  than  at  any  other  time,  and  the  fluids  of  the  mouth 
are  not  kept  in  circulation  between  the  teeth  by  means  of  the  tongue, 
lips,  and  cheeks.  Theoretically  the  teeth  should  be  thus  thoroughlv 
cleaned  after  each  meal,  but  "  satiety  breeds  disgust,"  and  it  is  not 
best  to  insist  on  more  than  will  probably  be  accomplished. 

Children  will  soon  learn  to  use  the  brush  and  floss  silk  themselves, 
and  finding  the  mouth  much  more  comfortable  when  "  clean  "  they  will 
endeavor  to  keep  it  so.  Many  a  child  has  been  denied  candy  for  years 
from  the  belief  that  "  sweets  decay  the  teeth,"  but  parents  may  be  as- 
sured that  no  harm  will  be  done  if  the  "  sweet "  is  not  allowed  to 
remain   between   and  around  the  teeth  till  it  becomes  acid,  and  that 


» 


67 G  ^fAXAGEMENT  OF  THE  DECIDUOUS  TEETH. 

may  hv  prevented  hv  cleansing;  the  tootli  attcr  the  candy  or  snu:ar  is 
eaten.  A  child  may  be  taught  cleanliness  in  this  manner  who  would 
bo  oidv  tau»rht  rebellion  by  the  repeated  denial  of  sweets,  the  reason  of 
which  he  cannot  understand. 

Prophylactic  mouth-washes  should  be  used — such  as  listerine  diluted 
to  a  10  per  cent,  solution. 


CHAPTER  XXiy. 

ORTHODONTIA. 

By  Edward  H.  Angle,  M.  D.,  D.  D.  S. 

Occlusion. 

The  term  "  irregularities  of  the  teeth,"  as  it  is  usually  applied  to 
express  the  condition  of  their  abnormal  arrangement,  does  not  properly- 
express  the  full  meaning  of  these  deformities.  The  term  "mal-occlu- 
sion  "  is  far  more  expressive,  for  in  studying  the  subject  we  must  fully 
appreciate  the  importance  of  the  dental  apparatus  as  a  whole,  and  the 
relations,  not  only  of  the  two  arches  to  each  other,  but  of  each  indi- 
vidual tooth  to  all  other  teeth  in  both  arches. 

The  shapes  of  the  cusps,  crowns,  roots,  and  even  the  very  structural 
material  of  the  teeth  and  their  attachments  are  all  designed  for  the  pur- 
pose of  making  occlusion  the  one  grand  object,  in  order  that  they  may 
best  serve  the  purpose  for  which  they  were  intended — namely,  the  cut- 
ting and  grinding  of  the  food. 

Examined  carefully,  it  will  be  seen  that  perfect  occlusion  is  incom- 
patible with  any  degree  of  mal-occlusion,  and  that  the  arrangement  of 
the  teeth  must  be  even  and  regular,  each  contributing  support  to  the 
others,  and  all  in  perfect  harmony.  Not  only  this,  but  the  jaws,  the 
muscles  of  mastication,  the  lips,  and  even  the  facial  lines  will  then  be 
in  best  harmony  with  the  peculiar  facial  type  of  the  individual. 

Therefore  we  should  be  constantly  impressed  with  the  importance  of 
normal  occlusion  in  the  study  and  treatment  of  these  deformities,  for  it 
is  the  very  basis  of  the  science.  So  in  the  following  pages  occlusion 
has  been  made  the  central  thought,  and  on  it  is  based  the  classification 
of  mal-occlusion,  as  well  as  the  nomenclature,  diagnosis,  and  treatment, 
and  the  definition  of  orthodontia  (from  the  Greek  dpdo;;,  straight ;  odou^, 
tooth),  as  that  science  which  has  for  its  object  the  correction  of  mal- 
occlusion of  the  teeth. 

Mal-occlusion  is  the  perversion  of  normal  occlusion,  and  for  its  intel- 
ligent comprehension  it  is  of  the  utmost  importance  that  we  first  thor- 
oughly consider  normal  occlusion,  and  the  principles  operative  in  estab- 
lishing and  maintaining  it. 

Occlusion,  as  the  basis  of  the  science  of  orthodontia,  is  the  student's 
most  important  lesson.  Its  proper  comprehension  presupposes  a  knowl- 
edge not  only  of  the  normal  relations  of  the  occlusal  surfaces  both  of 

677 


678 


ORTHODONTIA. 


permanent  and  deciduous  tcetli,  hut  of  their  forni.s,  structure,  and  at- 
tachments, their  growth  and  development,  as  well  as  that  of"  the  jaws 
and  related  muscles.  There  can  he  no  intelligent  comprehension  of  the 
subject  of  orthodontia  without  this  knowledge. 


Typiral  occlusion.    (Rronmcll.) 


The  perceptions  of  the  student  should  also  he  broadened  hv  a  com- 
parative study  of  the  teeth  of  the  lower  animals. 

By  referring  to  Figs.  oJ^JS,  594,  and  oHo,  which  represent  the  teeth  in 
ideal  or  normal  occlusion,  it  will  be  seen  that  each  dental  arch  <leseribes 


Fig.  o94. 


Typii-al  (icclu>iim      '~nmnia. 


a  graceful  cur\'e,  and  that  the  teeth  in  these  arches  are  so  arranged  as  to 
be  in  greatest  harmony  with  their  fellows  in  the  same  arch,  as  well  as  with 
those  in  the  op])osite  arch,  yet  that  each  case  differs  as  tvpes  of  faces  differ. 
The  curves  of  the  dental  arches,  the  inclinations  of  the  teeth,  their  sizes 


OCCLUSION. 


679 


and  lengths,  their  structure  and  dimensions,  all  vary  and  must  vary  to 
be  in  harmony  with  the  peculiar  type  and  temperament  of  the  indi- 
vidual, yet  all  are  exactly  the  same  in  the  main  principles  of  occlusion — 
principles  as  old  and  older  than  the  earliest  records  of  man's  teeth. 

The  lower  arch  is  somewhat  smaller  than  the  upper,  so  that  in  occlu- 
sion the  labial  and  buccal  surfaces  of  the  teeth  of  the  upper  jaw  slightly 
overhang  those  of  the  lower. 

The  key  to  occlusion  is  the  relative  positions  of  the  first  molars.  In 
normal  occlusion  the  raesio-buccal  cusp  of  the  upper  first  molar  is  re- 
ceived in  the  buccal  groove  of  the  lower  first  molar ;  the  teeth  posterior 
to  the  first  molars  engage  with  their  antagonists  in  a  precisely  similar 


Typical  occlusion.    (Cryer.) 

way ;  those  anterior  interlock  with  one  another  in  the  interspaces  until 
the  incisors  are  reached  ;  of  these  the  upper  usually  overhang  the  lower 
about  one-third  the  length  of  their  crowns,  though  the  length  of  over- 
bite varies,  being  greater  in  the  teeth  indicating  the  bilious  and  nervous 
temperaments,  and  less  in  the  sanguineous  and  lymphatic  types. 

The  upper  central  incisor  being  broader  than  the  lower,  it  necessarily 
extends  beyond  it  distally,  overlapping  in  addition  about  one-half  of  the 
lower  lateral  incisor;  the  upper  lateral  occludes  with  the  remaining  por- 
tion of  this  tooth  and  with  the  mesial  incline  of  the  lower  cuspid  ;  the 
mesial  incline  of  the  upper  cuspid  occludes  with  the  distal  incline  of  the 


680 


ORTHODONTIA. 


lower  cuspid,  the  distal  incline  of  the  upper  occliidinir  witji  the  mesial 
iiulinc  of  the  huccal  cusp  of  the  lower  first  premolar,  in  ilic  same 
order  the  series  of  hueeal  cusps  of  the  ]>remolars  occlude — the  mesial 
incline  of  each  upper  occluding  with  the  distid  incline  of  the  correspond- 
ing lower  tooth. 

Tile  distal  incline  of  the  second  upper  ]>remolar  occludes  with  the 
mesial  incline  of  the  mesio-huccal  cusp  of  the  lower  first  molar.  The 
tnesial  incline  of  the  inesio-l)uccal  cusp  of  the  upper  first  molar  occludes 
with  the  distal  incline  of  the  mesio-huccal  cusp  of  the  lower  first  tnolar ; 
the  distal    incline  of   the  mesio-buccal   cusp  of  the    upper  first  molar 

Fu;.  596. 


yiHCiil  iicclii>i<in  ;  liiij.'ii!)l  vii'W.     (Crycr.) 


occludes  with  the  mesial  incline  of  the  disto-huccal  cusp  of  the  lower 
first  molar;  the  mesial  incline  of  the  disto-huccal  cusp  of  the  upper  first 
molar  occludes  with  the  distal  incline  of  the  disto-buccal  cusp  of  the 
lower  first  molar,  and  the  distal  incline  of  the  disto-buccal  cusp  of  the 
upper  first  molar  occludes  with  the  mesial  incline  of  the  mesio-buccal 
cusj)  of  the  lower  second  molar.  This  same  order  is  continued  with 
the  buccal  cus])s  of  the  second  and  third  uj)j)('r  UKjlars,  the  distal 
incline  of  the  disto-buccal  cusp  of  the  U])per  third  molar  having  no 
occlusion. 

It  will    thus  be  seen   that  each  of  the  teeth  in  both  jaws  has  two 


OCCLUSION.  681 

antagonists  or  supports  in  the  opposite  jaw,  except  the  lower  central 
incisor  and  upper  third  molar. 

As  the  inclined  planes  match  and  harmonize  most  perfectly  in  the 
bucco-occlusal  relations  of  the  teeth,  so  there  is  a  similar  arrangement 
in  their  linguo-occlusal  relations,  except  that  the  lingual  cusps  of  the 
lower  premolars  and  molars  project  beyond  those  of  the  upper  teeth  into 
the  oral  space,  as  shown  in  Fig.  596. 

Likewise,  in  the  transverse  arrangement,  the  buccal  cusps  of  the  lower 
molars  and  premolars  pass  between  the  buccal  and  lingual  cusps  of  the 
upper  molars  and  premolars,  and  the  lingual  cusps  of  the  upper  molars 
and  premolars  pass  between  the  buccal  and  lingual  cusps  of  the  lower 
molars  and  premolars,  as  in  Fig.  597. 

The  grinding  surfaces  are  thus  enormously  increased  in  extent  and 

Fig.  597. 


Typical  occlusion  of  molars  ;  transverse  view.    (Cryer.) 

efficiency  over  what  would  be  possible  if  they  consisted  of  a  single  row 
of  cusps  or  of  plane  surfaces. 

But  increase  of  masticating  surface  is  not  the  only,  perhaps  not  even 
the  most  important,  reason  for  this  complex  interdigitation  of  the  cusps 
and  inclined  planes  of  the  teeth,  but  its  main  office  is  to  provide  for  the 
teeth  a  mutual  support.  The  sizes,  forms,  interdigitating  surfaces,  and 
positions  of  the  teeth  in  the  arches  are  such  as  to  give  to  one  another, 
singly  and  collectively,  the  greatest  possible  support  in  all  directions. 

Forces  Governing-  Normal  Occlusion. — An  important  part  played 
by  the  inclined  planes  of  the  cusps  of  the  teeth  already  in  normal  position 
is  the  influence  they  exert  over  teeth  that  may  be  erupting,  to  cause  them 
to  take  their  normal  positions  in  the  arch.  If,  on  the  other  hand,  their 
influence  be  perverted,  they  may  become  mischievous  factors  in  the  pro- 
duction of  mal-occlusion. 

When  the  teeth  first  emerge  from  the  gums  considerable  displacement 


G82  ORTHODONTIA. 

is  often  noticeable,  but  this  need  occasion  no  uneasiness,  provided,  as 
eruption  j)r()gres8es,  their  cusps  pass  under  the  inHiioncc  of  the  inclines 
of  normally  placed  opposimt;  cusps.  Rut  if  tliey  pass  l)cyond  this  influence 
into  al)norinal  ri'lations,  they  will  not  oidy  be  deflected  from  their  own 
proper  positions  in  the  arch,  but  they  will  assist  in  the  disj)lacemeut  of 
the  opposing  teeth,  and  of  those  which  are  to  follow  in  eruption  as  well. 
So  there  may  be  times  when  the  dividing-line  between  hannonv  and 
inharmony  of  occlusion  is  very  slight.  Hence  the  importance  of  careful 
attention  din-ing  the  important  period  covering  the  cruj)ti(m  of  the  per- 
manent teeth,  especially  the  beginnings. 

Harmony  between  the  upper  and  lower  arches  is  also  powerfully  j)ro- 
raoted  by  their  normal  action  and  reaction  upon  each  other  through  the 
t«eth.  As  the  teeth  in  the  lower  arch  erupt  before  those  of  the  upjxT, 
and  are  consequently  to  an  extent  fixed  in  their  positions  before  their 
antagonists  appear,  it  follows  that  the  lower  arch  is  the  form  over  which 
the  upper  is  molded.  In  other  words,  the  lo\ycr  arch  exerts  a  control- 
ling influence  over  the  form  of  the  upper  and  the  ])ositions  of  the  teeth 
therein.  Of  course,  the  upper  reacts  upon  the  lower,  but  it  is  unques- 
tionable, in  the  writer's  opinion,  that  the  lower  arch  is  the  more  impor- 
tant factor,  not  the  upper,  as  has  hitherto  been  taught. 

From  what  has  been  said,  it  may  be  readily  seen  how  greatly  each 
arch  contributes  to  the  other  in  maintaining  its  form  and  size  when  the 
teeth  are  in  normal  occlusion,  and  how  pressure  abnormally  exerted 
on  any  tooth  or  teeth  would  be  resisted  by  all  the  other  teeth.  For 
exam])le,  pressure  exerted  on  the  labial  surfaces  of  the  upper  incisors 
would  be  resisted  not  only  by  all  the  up})er  teeth  acting  as  blocks  of 
stone  do  in  an  arch  of  masonry,  but  also  by  the  teeth  of  the  lower 
arch  acting  through  occlusion. 

Inversely,  then,  one  arch  cannot  be  altered  in  shape  without  modi- 
fying that  of  the  other,  nor  can  it  be  altered  in  size  without  soon  exer- 
cising a  marked  effect  on  the  other. 

This  important  fact  is  of  the  greatest  interest  to  the  student  of 
orthodontia — namely,  that  in  normal  occlusion,  as  in  the  illustrative 
cases  shown,  each  tooth  is  not  only  in  harmony  with  every  other  tooth, 
but  each  tooth  helps  to  maintain  every  other  tooth  in  harmonious  rela- 
tions— for  the  cusps  interlock  and  each  inclined  occlusal  plane  serves 
to  prevent  each  tooth  from  sliding  out  of  position,  and  further  to  wedge 
it  into  position  if  slightly  malposed  ;  that  is,  if  not  beyond  the  normal 
influence  of  the  inclined  planes. 

A  careful  study  of  the  relations  of  the  inclined  occlusal  planes  and 
the  marginal,  triangular,  and  oblique  ridges,  in  connection  with  the 
movements  of  the  Jaw,  cannot  fail  to  impress  thoughtful  persons  not 
only  with  the  influence  which  these  exert  in  maintaining  each  individual 


OCCLUSION. 


683 


tooth  in  correct  position,  but  as  well  their  wonderful  efficiency  for 
incising  and  triturating  the  food  required  by  omnivorous  man,  and  with 
their  marvellous  arrangement  for  self-cleansing  and  consequent  self- 
preservation. 

Harmony  in  the  positions  of  the  teeth  and  in  the  sizes  and  relations 
of  the  arches  is  further  assisted  by  another  force — namely,  muscular 
pressure — the  tongue  acting  upon  the  inside  and  the  lips  and  cheeks 
upon  the  outside  of  tlie  arches.  The  latter,  if  normal  in  development 
and  function,  serve  to  keep  the  arches  from  spreading,  as  do  hoops 
upon  the  staves  of  a  cask  ;  the  former  prevents  too  great  encroachment 
upon  the  oral  space.  This  muscular  pressure  is  a  far  more  important 
factor  than  is  generally  recognized. 

So  it  will  be  seen  that  normal  occlusion  of  the  teeth  is  maintained, 


Fig.  598. 


first,  by  liarmony  in  the  sizes  and  relations  of  the  dental  arches  through 
the  interdependence  and  mutual  support  of  the  occlusal  inclined  planes 
of  the  teeth,  and  second,  by  the  influence  of  the  muscles  labially, 
buccally,  and  lingually.  The  illustrations  (Figs.  593,  594,  and  595) 
show  the  result  where  these  forces  have  acted  normally — a  harmoniously 
aligned  and  occluded  denture. 

Fig.  598  represents  the  teeth  of  a  child  aged  eight  years,  where  the 
jaws  and  teeth  are  developing  normally.  It  will  be  noted  that  all  of 
the  permanent  lower  incisors  have  erupted  and  occupy  their  normal 
positions  in  the  line  of  occlusion,  each  occupying  its  full  mesio-distal 
space  in  the  arch,  compelling  the  lower  canines  to  occupy  positions  the 
requisite  distance  apart,  and,  what  is  of  special  interest,  is  the  influence 


684  ORTHODONTIA. 

of  these  teetli  on  the  opposinj;  decicluous  caninos  through  tlu'ir  inclined 
planes.  Each  blow  th;it  the  iipjur  canines  receive  from  the  lower 
tends  to  widen  the  arch,  or  at  least  to  ])rcvcnt  it  from  becoming  nar- 
rower, in  marked  contrast  with  the  same  relations  of  the  case  shown  in 
Fig.  599,  where  the  lower  canines  have  lost  the  bracing  inflnenee  of  the 
lower  permanent  incisors  by  reason  of  the  disj)lacement  of  the  latter. 

Forces  Governing  Mal-occlusion. — These  forces  not  only  contribute 
to  maintaining  the  teeth  in  their  normal  positions  and  harmony  in  the 
sizes  of  the  arches,  but  they  are  equally  powerful  in  maintaining  inhar- 
mony  in  the  sizes  or  relations  of  the  arches  and  mal-occlusion  of  the 
teeth  when  once  established.  In  a  large  percentage  of  eases  of  mal- 
occlusion the  arches  are  more  or  less  contracted,  and  as  a  result  we  find 
the  teeth  crowded  and  overlapping.  In  these  cases  the  lips  serve  as 
constant  and   powerful   factors   in   maintaining  this  condition,  usually 

Fro.  599. 


acting  with  equal  effect  on  both  arches,  and  effectually  comliatting  any 
influence  of  the  tongue  or  any  inherent  tendency  on  the  part  of  nature 
toward  self-correction.  In  other  words,  the  narrow  and  diminished 
sizes  of  the  arches  are  fixed,  and  they  are  prevented  from  enlarging  by 
the  lips  with  a  force  equal  in  power  to  that  exerted  when  the  arches 
are  of  normal  size  and  the  teeth  in  normal  occlusion.  Likewise,  each 
inclined  plane  of  the  cusps  out  of  harmony  in  the  occlusion  serves  to 
maintain  it  in  its  malposition,  or  to  wedge  it  still  further  out  of  posi- 
tion upon  each  closure  of  the  jaw.  It  is  interesting  and  instructive  to 
note  the  result  of  these  forces  even  in  the  earliest  indications  of  mal- 
occlusion. 

Fig,  599  illustrates  a  very  common  and  familiar  form  of  developing 
mal-occlusion.  The  case  is  that  of  a  child  where  the  four  lower  per- 
manent incisors  are  fully  erupted,  but  one  of  them  (the  left  lateral)  has 
been  deflected  lingually  (Fig.  600).     The  arches  being  thus  deprived 


OCCLUSION.  685 

of  the  wedging  and  retaining  influence  of  this  tooth,  the  external  press- 
ure of  the  lips  has  closed  the  space  and  diminished  the  size  of  the 
arch.  At  the  same  time  pressure  of  the  lips  and  cheeks  (aided  by  the 
occlusal  planes)  is  gradually  molding  the  upper  arch  to  conform  to  the 
abnormal  size  of  the  lower. 

It  will  thus  be  seen  how  effectually  the  maintenance  of  the  mal- 
occlusion has  been  provided  for,  and  how  hopeless  it  is  to  expect  nature 
to  correct  this  deformity  unaided.  These  same  influences  may  be  traced 
in  a  similar  manner  in  any  case  of  mal-occlusion. 

Recognizing  the  potency  of  these  influences,  it  must  be  apparent 
that  cases  of  this  kind,  instead  of  being  self-corrective,  will  become 
more  and  more  complicated  as  time  goes  on  and  as  each  succeeding  per- 
manent tot)th  is  erupted.  In  all  such  cases  the  positions  of  the  erupt- 
ing permanent  lower  incisors  should  be  guarded  with  zealous  care,  and 

Fk4.  goo. 


should  be  maintained  by  corrective  procedure  if  necessary.  This  also 
applies  with  equal  force  to  any  other  lower  tooth  that  may  erupt  into 
abnormal  position,  especially  the  lower  first  molars.  Then,  unless  there 
be  unusual  influences  or  tendencies  toward  mal-occlusion,  the  positions 
of  the  teeth  in  the  upper  arch  will  be  directed  normally. 

On  the  other  hand,  for  the  reason  previously  stated,  if  the  teeth  of 
the  lower  arch  be  permitted  to  remain  in  malposition  even  to  the  slight- 
est overlapping  of  one  or  more  of  the  incisors  or  cuspids,  the  arch  will 
be  diminished  in  size  just  to  that  extent,  with  a  corresponding  contrac- 
tion in  the  upper  arch  and  some  form  of  bunching  of  the  teeth,  as  a 
result  of  the  influence  of  the  lips. 

So  we  can,  with  much  confidence,  by  examining  a  model  of  either 
the  upper  or  lower  arches  of  a  case  belonging  to  Class  I.,  determine  the 
extent  of  mal-occlusion  in  the  opposite  arch.  The  length  of  the  over- 
bite will,  of  course,  modify  this   rule,  though  but  slightly.     The  con- 


686  oRTHuDoyriA. 

forming  in  size  of"  one  arch  to  the  other  seonis  to  be  nature's  plan  of 
patching  up  her  deformities  in  order  to  render  the  teeth  as  efficient  as 
possible  even  in  mal-ocdusion.  The  figures  illustrating  Class  II., 
Division  2,  also  the  subdivision  of  this  division,  present  even  more 
striking  illustrations  of  the  influence  of  the  muscles  in  molding  the 
upper  arch  to  conform  to  the  size  of  the  lower. 

Finally,  recognizing  the  influence  of  the  muscles  and  of  the  inclined 
planes  of  the  teeth  in  establishing  and  maintaining  harmony  in  the 
sizes  and  relations  of  the  arches  and  in  the  occlusion  of  the  teeth,  the 
folly  of  correcting  malpositions  of  the  teeth  in  the  upper  arch  alone, 
without  e(pial  attention  to  those  of  the  lower,  as  is  so  often  done, 
becomes  apparent. 

Line  of  Occlusion. — When  the  teeth  are  in  normal  occlusion,  their 
greatest  number  of  points  of  contact  will  be  found  to  lie  along  an 
imaginary  line  passing  over  the  points  of  the  buccal  cusps  of  the  molars 
ami  premolars,  and  the  cutting  edges  of  the  canines  and  incisors  of  the 
lower  arch,  and  along  the  sulcus  between  the  buccal  and  lingual  cusps 
of  the  upper  molars  and  premolars,  thence  forward,  crossing  the  lin- 
gual ridge  of  the  canines  and  the  marginal  ridges  of  the  incisors  at  a 
point  about  one-third  the  length  of  their  crowns  from  their  cutting 
edges.  This  will  be  called  the  line  of  occlusion,  and  defined  as  being 
the  line  of  greatest  normal  occlusal  contact  of  the  teeth. 

This  line  describes  more  or  less  of  a  parabolic  curve,  and  varies 
somewhat  within  the  limits  of  the  normal,  according  to  the  race,  type, 
len)j)erament,  etc.,  of  the  individual  ;  therefore  the  normal  form  of  this 
line  must  be  determined  in  any  given  case  by  the  judgment  of  the 
operator  after  a  careful  study  of  the  features,  facial  lines,  forms  of 
teeth,  as  related  to  the  temjierament,  etc. 

In  the  diagnosis  of  cases  it  is  im])ortant  that  we  should  have  this 
definite  line  as  a  more  accurate  basis  from  which  to  reason  and  note 
variations  than  the  less  definite  outline  as  indicated  by  the  incisive  and 
occlusal  surfaces  of  the  teeth. 

All  teeth  found  out  of  harmonv  with  the  line  of  occlusion  occujiy 
positions  of  mal-occlusion,  and  each  tooth  may  occupy  any  of  .seven 
malpositions  or  their  various  deviations  and  possible  combinations. 

The  malj)()sitions  of  teeth  consist  principally  in  the  variations  from 
the  normal  of  the  positions  of  their  crowns,  with  usually  little  displace- 
ment of  the  apices  of  their  roots,  so  that  they  incline  at  an  angle  more 
or  less  oblique  from  the  normal.  In  .some  instances,  however,  there 
is  some  displacement  of  the  apices  of  the  roots,  as  well  as  of  the  crowns, 
they  having  either  developed  in  malpositions,  or  having,  as  in  most 
instances,  been  forced  from  their  normal  positions  by  the  eruption  of 
more  powerful  teeth  in  juxtaposition,  as,  for  example,  the  common  di.s- 


CLASSIFICATION  AND  DIAGNOSIS.  687 

placement  lingually  of  the  lateral  incisors  by  the  development  and 
eruption  of  the  canines,  as  in  Fig.  601.  Yet  even  in  such  cases  the 
displacement  of  the  apices  is  more  apparent  than  real,  the  marked 
malpositions  which  the  crowns  occupy  lending  to  the  appearance  of 
displacement  of  the  points  of  their  roots. 

Nomenclature. — A  definite  nomenclature  is  as  necessary  in  orthodon- 
tia as  in  anatomy.  The  terms  for  describing  the  various  malpositions 
should  be  so  precise  as  to  convey  at  once  a  clear  idea  of  the  nature  of 
the  malposition  to  be  corrected.  The  writer,  therefore,  suggests  the 
following,  which,  while  perhaps  not  perfect,  still  seems  to  be  a  great 
improvement  over  present  usage  : 

For  example,  a  tooth  outside  of  the  line  of  occlusion  may  be  said  to  be 
in  buccal  (or  labial)  occlusion  ;  when  inside  this  line,  in  lingual  occlusion  ; 
if  farther  forward,  or  mesial,  than  normal,  in  mesial  occlusion;  if  in  the 
opposite  direction,  in  distal  occlusion  ;  if  turned  on  its  axis,  it  would  be 
in  torso-occlusion.  Teeth  not  sufficiently  elevated  in  their  sockets  would 
be  in  infra-occlusion,  and  those  that  occupy  positions  of  too  great  eleva- 
tion would  be  in  supra-occlusion. 

These  different  malpositions,  in  their  modifications  and  combinations, 
form  the  basis  of  limitless  variations  of  occlusion  from  the  normal,  from 
the  simplest  to  the  most  complex,  in  which  may  be  involved  not  only 
the  malpositions  of  all  the  teeth,  but  even  the  relations  of  the  jaws, 
resulting  in  marked  deformities,  and  producing  appearances  even  repul- 
sive. 

Classification  and  Diagnosis. 

In  diagnosing  cases  of  mal-occlusion  we  must  consider,  first,  the 
mesio-distal  relations  of  the  jaws  and  dental  arches  ;  second,  the  posi- 
tions of  the  individual  teeth. 

As  has  before  been  stated,  the  first  permanent  molars  are  the  keys 
to  occlusion.  They  are  the  first  permanent  teeth  to  erupt,  the  largest  in 
size,  the  most  constant  and  normal  as  to  position  (especially  the  upper), 
thereby  determining  the  length  of  bite  of  the  teeth  which  are  to  fi)]]ow 
in  eruption,  and  whether  the  lower  lock  normally  with  the  upper,  or 
distally  or  mesially  to  their  normal  relations,  is  determined  to  which  of 
the  three  possible  classes  each  case  of  mal-occlusion  belongs. 

Class  L,  illustrated  by  Fig.  601,  is  characterized  by  normal  mesio- 
distal  relations  of  the  jaws  and  dental  arches,  and  normal  locking  of  the 
first  molars ;  that  is,  mesio-distally.  One  or  even  all  of  the  molars  may 
be  in  buccal  or  lingual  occlusion,  but  this  is  only  an  incident  and  may 
occur  in  any  class,  and  is  not  constant  in,  nor  a  characteristic  peculiar 
to,  any  particular  class. 

In  this  class  the  mal-occlusion  ranges  from  the  slightest  overlap]>ing 


688  ORTHODONTIA. 

of  a  sintjle  tooth  to  tlio  most  complex  derangement,  involving  the  posi- 
tion of  every  tooth  in  both  arches,  as  in  Fig.  732.     In  the  average  case 

Fif!.  cm 


(Fig.  601),  however,  tiie  arehes  are  more  or  less  shortened  and  rednced 
in  size,  with  a  corresponding  crowding  of  the  anterior  teeth. 


Fig.  60-2. 


Class  II. — When  the  lower  jaw  is  distal  to  its  normal  relation  with 
the  npper  jaw,  and  the  lower  first  molars  lock  distally  to  normal,  it  must 


CLASSIFICATION  AND  DIAGNOSIS. 


689 


necessarily  follow  that  every  succeeding  permanent  tooth  to  erupt  must 
also  occlude  abnormally,  all  the  lower  teeth  being  forced  into  positions 
of  distal  occlusion,  causing  retrusion  of  the  entire  lower  jaw.  This 
condition  of  distal  occlusion  is  the  determining  characteristic  of  Class 
II.,  and  it  produces  very  marked  and  very  characteristic  inharmony  in 
the  facial  lines. 

Of  this  class  there  are  two  divisions,  each  having  a  subdivision  : 
Division  1  is  characterized  by  distal  occlusion  of  both  lateral  halves 
of  the  dental  arches,  a  narrowed  upper  arch,  lengthened  and  protruding 
upper  incisors,  short  and  practically  functionless  upper  lip,  lengthened 

Fig.  G03. 


lower  incisors  and  thickened  lower  lip  which  rests  cushion-like  between 
the  upper  and  lower  incisors,  increasing  the  protrusion  of  the  former 
and  the  retrusion  of  the  latter.  This  form  of  mal-occlusion  is  always 
accompanied  and  aggravated,  at  least  in  its  early  stages,  indeed,  if  not 
caused,  by  mouth-breathing  due  to  some  form  of  nasal  obstruction.  The 
mal-occlusion  typical  of  this  class  is  shown  in  Fig.  602. 

Subdivision,  Division  1,  has  the  same  characteristics,  differing  only  in 
that  the  distal  occlusion  is  unilateral,  as  shown  in  Fig.  603. 

Division  2  is  characterized  also  by  distal  occlusion  of  both  lateral 
halves  of  the  dental  arches,  and   retrusion  instead  of  protrusion  of  the 


44 


GDU  ORTJlnDoyriA. 

uppiT  incisors.  In  this  divi.-ion  tlicrc  arc  no  coniplicMtions  tVoin  patlio- 
logical  conditions  of"  tlic  nasal  jiassages,  hence  the  moutli  is  kept  closed 
the  normal  anionnt  of"  time,  and  the  li])s  jierf'orni  their  normal  f'nnctions, 
which  causes  the  rc])rcssion  of  the  ii])per  incisors  nntil  they  come  in 
contact  with  the  already  rctnidcd  lower  incisors,  cansinii'  crowding  (»f" 
the  n])per  tei'th  in  the  canine  region,  or  at  the  angles  of"  tlu;  month,  where 
the  fm'ce  from  lip  prcssnre  is  not  so  great,  as  shown  in  Fig.  <)()4. 

SubdivLsioti,  Dlrisioii,  ,\  has  the  same  characterisf ics  as  the  principal 

Fui.  GU4. 


division,  differing  cliiefly  in  tliat  the  molar  occlusion  is  nnilateraliy 
distal,  as  shown  in  Fig.  605. 

The  marring  effect  on  the  facial  lines  of  the  nial-ocelusion  of  division 
2  and  its  subdivision  is  iwth  marked  and  characteristic. 

Class  III.  is  characterized  by  mesial  occlusion  in  both  lateral  halves 
of  the  dental  arches,  the  width  of  one  cusj)  in  the  beginning  or  in 
simple  cases,  but  more  in  more  ])ronounc('d  cases,  as  in  Fig.  606,  for 
these  cases  are  always  progressive,     In  cases  belonging  to  this  class, 


CLASSIFICATION  AND  DIAGNOSIS. 


691 


the  arrangement  of   the  teeth  in  their  respective  arches  varies  greatly 
from  quite  even  and  regular  alignment  to  considerable  crowding,  espe- 


FiG.  605. 


cially  in  the  upper  arch.     There  is  usually  a  decided  lingual  inclination 
of  the  lower  incisors  and  canines,  which  becomes  more  and  more  pro- 


Fig    eOfi 


nounced  as  the  case  progresses,  and  which  is  due  to  the  pressure  of  the 
lower  lip  in  the  effort  to  close  the  mouth. 

In  addition  to  the  inharmony  in  the  relations  of  the  jaws,  there  is 


692 


ORTHODONTIA. 


usually  inharmony  also  in  the  sizes  of  the  two  dental  arches,  especially 
in  fully  developed  cases,  due  to  the  asymmetrical  development  of  the 
maxillary  bones,  the  angle  of  the  lower  jaw  being  more  obtuse  than 
normal,  but  it  may  also  be  the  result  of  overdevelopment  in  the  bodv 
of  the  jaw.  Other  characteristics  met  with  in  this  class  are  considered 
in  the  section  on  Treatment,  page  839. 

Fi(i.  C07. 


In  all  cases  belonging  to  this  class  the  marring  of  the  facial  lines  is 
most  noticeable,  and  in  direct  proportion  to  the  extent  of  mal-occlusion 
(Figs.  807  and  815). 

Subdivimon,  Class  III. — This  subdivision  differs  from  the  principal 
division  only  in  degree,  one  of  the  lateral  halves  of  the  arch  only  being 
in  mesial  occlusion,  the  other  being  normal,  as  shown  in  Fig.  607,  the 
arches  crossing  in  the  region  of  the  incisors. 


CLASSIFICATION  AND  DIAGNOSIS.  693 

That  all  cases  of  mal-occlusion  met  with  will  be  found  to  be 
embraced  in  the  above  classification  is  more  than  probable.  There 
still  remains,  however,  one  possible  class — viz.,  where  one  of  the  lateral 
halves  of  the  lower  arch  is  in  mesial  occlusion  while  the  other  is  in 
distal  occlusion ;  but  cases  having  these  characteristics  are  so  very  rare 
that  no  further  reference  to  them  is  necessary,  the  writer  having  never 
seen  but  one  or  two  cases. 

In  diagnosing  cases  according  to  the  above  classification,  it  will  be 
seen  that  the  occlusion  of  each  of  the  lateral  halves  of  the  arches  is 
important,  and  must  be  considered  separately  and  with  equal  and  care- 
ful attention,  always  beginning  with  the  first  permanent  molars. 

In  developing  cases  of  the  second  and  third  classes  when  the  lower 
jaw  may  be  in  a  state  of  transition  and  has  not  attained  to  distal  or 
mesial  occlusion  the  full  width  of  a  cusp  on  one  or  both  sides,  the 
beginner  may  be  a  little  puzzled  as  to  the  proper  classification,  but 
upon  careful  inspection  and  close  study  a  majority  of  the  inclined 
planes  will  be  found  to  favor  one  particular  class,  the  co-relation  of  the 
first  molars  being,  of  course,  the  most  important  factor. 

The  loss  of  a  tooth  or  teeth  by  extraction  is  followed  by  such  marked 
changes  in  the  positions  of  the  remaining  teeth  that  diagnosis  is  some- 
times greatly  complicated.  Therefore  great  care  and  judgment  should 
be  exercised,  making  allowance  for  the  tipping  of  teeth  and  other 
changes  which  have  taken  place  as  a  result  of  extraction,  in  order  to 
determine  their  original  positions.  This  point  being  decided,  the  cor- 
rect diagnosis  according  to  the  above  classification  becomes  easy. 

A  brief  recapitulation  of  the  classification  is  here  given  for  con- 
venience of  study  and  for  ready  reference  : 

Class  I. — Arches  in  normal  mesio-distal  relations. 
Class  II. — Lower  arch  distal  to  normal  in  its  relation  to  upper  arch. 
Division  1. — Bilaterally  distal,  protruding  upper  incisors.  Usually 
mouth-breathers. 
Subdivision. — Unilaterally    distal,    protruding    upper    incisors. 
Usually  mouth-breathers. 
Division  2. — Bilaterally  distal,  retruding  upper  incisors.     Normal 
breathers. 
Subdivision. — Unilaterally    distal,    retruding    upper     incisors. 
Normal  breathers. 
Class  III. — Lower  arch   mesial  to  normal   in  its  relation  to  upper 
arch. 
Division. — Bilaterally  mesial. 

Subdivision. — Unilaterally  mesial. 
Out  of  several  thousand  cases  of  mal-occlnsion  examined,  the  pro- 
portion per  thousand  belonging  to  each  class  was  as  follows : 


694  ORTHODOM'IA. 

Class  1 G92 

Class  II. 

Division  1 ',10 

Siibtlivision 'M 

Division  2 42 

SuUlivision lUO 

Class  III. 

Division 34 

Subdivision 8 

1000 

Facial  Art. 

Art,  as  related  to  tlie  human  face,  must  ever  have  an  important 
bearing  on  the  study  of  orthodontia,  for  the  mouth  is  a  most  potent 
factor  ill  making  or  marring  the  beauty  and  character  of  the  face,  and 
the  positions  of  the  teeth  are  to  a  very  large  extent  responsible  for  the 
proper  form  and  beauty^-or  the  lack  of  it — of  the  mouth.  No  one 
can  be  beautiful  unless  the  mouth  is  in  harmony  with  all  the  other 
features,  and  no  one  afflicted  with  mal-occliision  can  have  a  mouth  that 
is  thus  in  harmony. 

The  duties  of  the  orthodontist  force  upon  him  great  responsibilities, 
ami  there  is  nothing  in  which  the  student  of  orthodontia  should  be  more 
keenlv  interested  nor  better  iiubrmed  than  in  the  study  of  tlw  artistic 
proportions  and  relations  of  the  features  of  the  iinmanface;  for  each 
of  his  efforts,  whether  he  realizes  it  or  not,  makes  for  beauty  or  ugli- 
ness, for  harmony  or  inharmony,  for  perfection  or  deformity. 

The  orthodontist  must  ever  place  foremost  in  importance  the  normal 
occlusion  of  the  teeth,  for  only  in  normal  occlusion  is  their  greatest 
usefulness  and  beauty  possible.  Many  patients  would  never  seek  treat- 
ment were  it  not  that  the  mal-occlusion  of  their  teeth  produced  inliar- 
mony  in  the  lines  of  their  faces,  and  the  improvement  in  the  beauty 
of  ])roj)()rtiou  and  artistic  effect  which  may  often  be  wrought  by  intel- 
liiient  effort  on  the  ])art  of  the  orthoilontist  is  marvellous  and  almost 
incredible;  hut  his  efforts  may  also  be  ('(lunlly  ctticacioiis  in  iiroducing 
or  enhancing  ugliness  and  deformity  if  unintclligciitly  directed. 

But  in  order  that  our  efforts  may  be  intelligently  directe<l  toward 
the  ideal,  there  must  be  some  grand  j^rineiple  as  a  basis  from  which  to 
reason,  or  we  must  be  but  gropers  in  the  dark,  exi)erimenters,  produc- 
ing results  which  mav  caus(>  embarrassment  or  even  bitter  regret. 

Thouirh  human  faces  are  all  y-roatlv  alike,  vet  all  differ.  Lines  and 
rules  for  their  measurement  have  ever  been  sought  by  artists,  aii<l  many 
have  been  the  plans  for  determining  some  basic  line  or  principle  from 
which  to  detect  variations  from  the  normal,  i)Ut  no  line,  no  measurement, 
admits  of  anything  nearly  like  niiiver.sal  aj>plication. 

The   beautiful   face   of  the   Apollo  Belvedere  has  very  largely  been 


FACIAL  ART. 


695 


used  as  a  guide  toward  the  ideal  and  from  which  to  judge  variations,  but 
this  is  impracticable  and  misleading,  for,  notwithstanding  the  beautiful 
harmony  of  proportions  of  this  face,  with  its  straight  line  touching  the 
frontal  and  mental  eminences  and  the  middle  of  the  wing  of  the  nose,  its 
range  of  application  has  been  found  to  be  very  limited  in  gauging  the 
harmony  or  inharmony  of  a  very  large  number  of  other  faces. 

This  is  easily  understood  when  we  remember  that  the  Apollo  face 
represents  the  type  or  ideal  of  Grecian  beauty,  while  now  the  Greek  type 
is  rarely  seen,  and  in  its  place  we  have,  especially  in  America,  many 
types  and  the  greatest  number  of  variations  of  each  type,  each  face  being 

Fig.  608. 


practically  a  law  unto  itself,  and  presenting  demands  as  to  measurements 
and  proportions  peculiar  to  itself. 

According  to  one  of  our  foremost  teachers  of  art,  Mr.  E.  H.  Wuerpel, 
there  is  a  principle  for  our  use  M'hich  is  equally  applicable  to  all  faces — 
viz.,  the  principle  of  balance,  of  symmetry.  We  must  be  able  to  detect 
whether  the  features — that  is,  the  forehead,  the  nose,  the  chin,  the  lips — 
of  each  individual  face  balance,  harmonize,  or  whether  they  are  out  of 
balance,  out  of  harmony,  and  especially  .whether  the  month  is  in  harmo- 
nious relations  with  the  other  features,  and,  if  it  is  not,  what  is  necessary 
to  place  it  in  balance. 


696 


ORTHODONTIA. 


Tlio  faculty  of  (leteriniiiiii<;  the  proper  halaucc  of  the  features  is  a 
difficult  one  to  attain.  The  authority  above  referred  to  says  that  only 
one  in  two  or  three  hundred  art  students  ever  succeed  in   niasterintr  it. 


Fig.  t;uu. 


Fit;.  GIU. 


i; 


and  tiiese  only  after  niucli  observation  and  practice  in   sketching  and 
modelling  faces. 


Fio.  611. 


Fk;.  G12. 


Unpromising  as  this  seems,  it  is  doubtless  correct,  yet  we  have  a  rule 
for  determining  tlie  best  balance  of  the  features,  or  at  least  the  best 


FACIAL  ART. 


697 


balance  of  the  mouth  with  the  rest  of  the  features,  that  artists  probably 
know  nothing  of,  and  one  that  for  the  orthodontist  is  more  unvarying  and 
more  reliable  than  even  the  judgment  of  the  favored  few — a  rule  so 


Fig.  613. 


invariable  and  with  so  few  exceptions  that  we  may  consider  it  a  law, 
and  if  it  be  not  applicable  in  all  cases,  the   exceptions  will   be   so 


Fig.  614. 


very  rare  that  they  are  hardly  worth  considering.     It  is,  furthermore,  a 
rule  so  plain  and  so  simple  that  all  can  understand  and  apply  it.     It  is 


61)8  ORTHODONTIA. 

tluit  the  best  balance,  the  best  haniiony,  the  best  j^roportions  of  the 
mouth,  ill  its  rehitioiis  to  the  other  features,  recjiiire  that  there  shall 
be  the  full  eoniplenient  of  teeth,  and  that  each  tooth  shall  be  made  to 
occupy  its  normal  position — normal  occlusion. 

Fig.  608  shows  the  face  of  A})ollo,  The  face  is  a  study  of  symmetry 
and  harmony  of  proportion,  and  such  lines  are  wholly  incompatible  with 
teeth  in  mal-occlusion  or  without  the  full  number  of  teeth. 

Fig.  GUI)  .shows  another  face,  which  is  also  one  of  much  bcautv  and 
fine  proportions.  It  is  also  somewhat  of  a  (ireek  ty])c,  and  the  lower 
half  of  the  face  shows  lines  which  could  only  have  been  molded  over 
teeth  normal  in  number  and  position,  and  accompanied  by  normal  con- 
ditions of  development  and  nasal  function. 

Fig.  010'  shows  a  face  that  is  a  blending  of  the  CJreek  and   Roman 

Fjg.  Gl.j. 


types,  and  it  also  is  in  fine  balance,  though  very  ditt'crent  from  that  of 
Apollo.  The  features  are  large  and  [)roiiiiiient  and  the  head  is  large, 
i)ut  there  is  a  harmony  of  size,  relation,  and  ])ro|)ortion  that  forms  a 
most  pleasing  whole.  The  face,  while  in  fine  balance,  is  ])erlia])s  not 
beautiful  from  a  physical  standj)oint,l)ut  it  is  more.  It  is  beautiful  from 
an  intellectual  standpoint,  possessing  strength,  nobility,  majesty — that, 
in  the  Avriter's  opinion,  is  lamentably  lacking  in  the  Apollo  fiice. 

Figs.  611  and  612,  and  Fig.  613  show  the  faces  of  two  normally  devel- 
oping children,  though  it  will  be  observed  that  they  are  of  strikingly  dif- 
ferent types.  The  proportions  of  the  faces,  the  balance  of  the  features, 
and  the  harmonious  lines  of  the  mouths  tell  as  truthfully  that  they  are 
being  molded  over  teeth  developing  normally  in  normal  occlusion  as  the 
models  of  the  teeth  themselves,  shown  in  Figs.  614  and  615. 

1  William  Whipple. 


FACIAL  ART. 


699 


In  these  cases  nature  has  been  able  to  work  unhampered  by  detri- 
mental pathological  conditions,  which  is  apparent  in  the  results. 

Of  course,  it  must  be  understood  that  changes  in  the  contour  of  these 
young  faces  must  take  place  witli  greater  development.  The  noses  and 
chins  will  develop  and  become  more  prominent,  and  after  the  eruption 
of  the  permanent  canines  there  will  be  more  of  an  acute  angle  between 
the  nose  and  the  upper  lip,  especially  in  the  face  shown  in  Fig.  613. 
But  the  point  we  AV'Ould  emphasize  is  the  normal  development  and  con- 
sequent normal  balance  and  symmetry  of  these  faces,  and  if  we  will 
notice  any  child,  or  any  person  who  has  reached  maturity  with  the  teeth 
in  normal  occlusion,  we  will  find  an  equal  harmony  of  balance  of  the 
mouth  with  the  other  features.  It  has  been  well  said  that  "  probably 
tiie  greatest  reason  why  there  is  such  uniformity  of  harmony  in  the  facial 
lines  of  young  children  is  that  their  teeth  (the  deciduous  teeth)  are  prac- 
tically free  from  mal-occlusion  "  (Dr.  R.  Anema). 

Fig.  616. 


The  writer  would  not  be  understood  as  implying  that  every  face  with 
lines  and  features  in  harmony  of  balance  must  necessarily  be  beautiful, 
nor  even  that  placing  mal-occluded  teeth  in  normal  occlusion  will  always 
put  the  whole  ilioe  in  harmony  of  balance.  There  may  be  defects  in  the 
face,  as  lack  of  development  of  the  nose  or  chin,  or  unequal  develop- 
ment of  the  malar  bones  or  any  of  the  bones  of  the  face,  or  defects  in 
the  eyes  or  ears,  or  in  the  shape  of  the  head,  which,  of  course,  could  not 
be  remedied  by  the  correction  of  mal-occlusion,  but  the  best  harmony  of 
such  faces,  or  of  any  face,  is  only  possible  when  the  teeth  are  in  normal 
occlusion.  Mal-occlusion,  or  the  loss  of  teeth  l>y  extraction  or  non- 
eruption,  or  a  combination  of  these  two  causes,  are  responsible  for  far 
more  faces  out  of  balance  and  out  of  harmony  than  any  other  cause 
or  combination  of  causes,  and  this  inharmony  and  lack  of  balance  of 
the  mouth  exists  just  in  proportion  to  the  degree  of  mal-occlusion. 

For  a  true  understanding  of  what  is  meant  by  harmony  of  proportion 
and  balance  of  faces,  a  careful  study  must  be  made  of  faces  that  are  out 
of  balance  as  well  as  of  those  that  are  in  balance. 


700 


ORTHODONTIA. 


The  effect  on  tlie  fticial  lines  of"  the  varvinff  forms  of  nial-oeelusion 
foinul  in  the  three  different  ehisses  varies  not  only  with  the  dt'gree  of 
nial-oeclnsion,  but  also  with  the  individual  tyj)c  of  faee,  yet,  notwith- 
standing this,  the  type  of  faeial  deformity  produced  by  each  separate 
class  of  mal-occlusion  is  so  constant  that,  after  some  practice,  the  close 
observer  may  classify  with  much  accuracy  the  mal-occlusion  of  the  peo- 
ple he  observes  without  an  actual  examination  of  their  teeth.  This  is 
also  true  in  the  case  of  extraction,  or  the  loss  or  lack  of  teeth  from  any 

cause. 

Fici.  617. 


In  Class  I.  the  chin  and  nose  will  usually  be  found  in  relatively 
normal  balance  with  the  forehead  and  general  contour  of  the  face,  and 
the  lines  of  abnormality  confined  more  or  less  to  the  mouth  itself. 

Fig.  616  shows  such  a  case  in  the  profile  of  a  boy  fourteen  years  of 
age,  and  the  lack  of  balance  in  the  flat  and  sunken  lines  of  the  mouth 
clearly  indicates  diminished  sizes  of  the  dental  arches.  This  lack  of 
normal  contour  of  the  mouth  will  be  more  impressive  when  it  is  remem- 
bered that  at  this  age  a  boy's  mouth  should  be  relatively  more  prominent 
than  that  of  a  man,  for  the  reason  that  his  face  has  not  yet  reached  its 
full  growth,  while  the  teeth  are  full-sized  at  eruption. 


FACIAL  ART.  701 

Fig.  601  shows  the  reason  for  this  lack  of  normal  contour — namely, 
lack  in  the  development  of  the  alveolar  process  and  pronounced  crowd- 
ing of  the  teeth. 

The  correctness  of  our  rule  is  verified  in  the  corrected  occlusion, 
shown  in  Fig.  744,  and  in  the  restored  facial  lines  in  Fig.  617. 

Fig.  618  shows  the  profile  of  the  face  of  another  boy,  aged  eleven, 
whose  facial  lines  were  also  thrown  out  of  balance  by  reason  of  mal- 
occlusion of  his  teeth.  Class  I.  Again,  it  will  be  noticed  that  the  chin 
and  nose  are  in  good  harmony  with  the  general  contour  of  the  face,  and 
that  the  lack  of  balance  is  confined  to  the  mouth,  and  that  this  time 
the  lips,  both  upper  and  lower,  instead  of  being  flat  and  sunken,  as  in 

Fio.  618. 


the  last  case,  are  too  full  and  prominent.  By  referring  to  the  mal-occlu- 
sion  shown  in  Figs.  755  and  756,  we  at  once  see  the  reason.  The  teeth, 
instead  of  being  bunched  in  the  canine  region  and  flattened  in  front, 
are  bunched,  rotated,  and  prominent  in  the  incisor  region.  Another 
point  will  be  noted  in  this  connection — namely,  that  it  is  the  unnatural 
position  and  prominence  of  the  upper  teeth  that  causes  the  lower  lip  to 
protrude.  When  the  lips  are  closed  naturally  over  teeth  in  normal 
occlusion,  the  lower  lip  rests  against  the  tips  of  the  upper  incisors,  and 
it  is  the  upper  teeth,  not  the  lower,  as  is  usually  supposed,  that  estab- 
lish the  curve  of  the  lower  lip.  In  this  case,  however,  there  is  also 
another  reason  why  the  lips  are  so  prominent — namely,  that  owing  to  the 
excessive  overbite  (due  to  crowding  of  the  incisors)  the  space  for  the 


7(12 


ORTHODOyTIA. 


lips  is  too  short  for  their  iKitiinil  (•h)sun',  and  wlion  brought  together 
tht'v  aro  protnided  unnaturally,  •rivint;  an  <'.\|)r('ssi()n  as  of  pouting  to 
tlu*  mouth. 

Fitr.  7(30  shows  the  occlusion  at"t<'r  each  tooth  had  heeii  norinallv 
placed,  whii'h  also  natiu'ally  resulted  in  <stal>lisliinir  the  normal  leiiii-th 
t>f  bite,  and  the  phu-iui:;  of"  the  features  in  fine  l)alance,  as  shown  in  V\]i,. 
619. 

Fig.   620    shows    the    profile   of"   a  youn<r  <::irl   whose   lual-occlusion, 
belongs  U)  Division  1,  Class  11.,  and    the   lines   of"  inharmony  shown   in 
this  face  are  characteristic  of"  all   c:ases  of  this  division  of"  this  class  of" 
mal-occlusion,  and  also  of"  the  subdivision. 

In  cases  belonging  to  the   first   class,  as  we   have  .seen,  the  mouth  i.s 

Fi(i.  019. 


Fk;.  (i-20. 


the  only  feature  greatly  out  of  harmony  ;  but  in  these  cases  tlie  nose, 
the  mouth,  and  the  chin  must  be  greatly  out  of  balance,  both  with  each 
other  and  w  ith  the  general  contom-  of  the  face,  due  t(»  the  tyi)e  (distal) 
of  mal-occlusion  of  this  cla.ss,  as  illustrated  in  Fig.  602. 

To  attempt  to  restore  balance  and  harmony  of  ])roi)ortion  to  this 
face  by  placing  all  the  teeth  in  normal  occlusion  is  perhaps  to  .seem  to 
put  onr  rule  to  a  severe  test,  but  its  correctness  is  shown  in  the  result 
on  the  facial  lines  in  Fig.  621,  and  while  the  face  may  still  not  be  beau- 
tiful, we  believe  that  by  no  other  means  could  it  have  been  placed  in  so 
nearly  ideal  balance  or  harmony.  It  will  be  observed  that  this  type  of 
face  differs  greatly  from  the  straight-line  A])ollo  face;  yet  in  cases  of 
mal-occlusion  both  types  of  face  are  eciually  susceptible  of  being  restored 


FACIAL   ART. 


703 


to  the  correct  balance  normal  to  each,  and  both  by  the  same  method — 
namely,  the  establishment  of  normal  occlusion. 

Since  in  this  case  there  has  been  established  normal  relations  of  the 
muscles  and  of  the  inclined  planes  of  the  teeth,  and  normal  nasal 
respiration  has  also  been  established,  the  further  development  of  this 
face  will  be  toward  the  normal — toward  harmony — instead  of  in  the 
opposite  direction,  as  had  been  the  case  since  the  day  the  nasal  trouble 
first  caused  mouth-breathing,  or  since  the  first  abnormal  locking  of  thet 
inclined  planes  of  the  first  permanent  molars. 

The  face  on  the  left  of  Fig.  622  shows  the  profile  of  a  young  man's 
face  which  is  fairly  typical  of  the  lack  of  balance  of  facial  lines  due  to 

Fio.  621. 


mal-occlusion  of  the  second  division  of  Class  II.  The  mal-occlusion 
is  shown  in  Fig.  795. 

The  head  is  large  and  well  shaped,  and  the  forehead  and  nose  strong 
and  in  good  balance,  but  there  is  a  weakness  about  the  mouth  and  chin 
that  is  greatly  out  of  keeping  with  the  general  contour  of  the  head. 
We  have  but  to  study  the  mal-occlusion  to  readily  detect  the  cause — 
namely,  distal  occlusion  with  normal  nasal  and  lip  functions  which  have 
pushed  the  upper  incisors  back  to  occlude  with  the  retruded  lower 
incisors  and  caused  a  crowding  and  overlapping  in  the  canine  region. 

Again,  the  rule  was  applied  and  each  tooth  made  to  occupv  its  nor- 
mal position.  Math  the  most  gratifying  result  on  the  facial  lines,  sliown 
on  the  face  in  the  right  of  Fig.  622.  Those  weak  lines  of  inharmony 
have  been  changed  to  others  of  strength  and  harmony  of  balance,  in 


704 


ORTHODONTIA. 


contrast   to    the    lines    that   must   have  followed  had    extraction  been 
resorted  to  as  the  plan  of  treatment. 

The  restored  occlusion  is  shown  in  Fig.  796. 

The  disfiguring  effect  on  the   face  caused  by  mal-occlusipn  of  the 


Fig.  (V22. 


subdivision  of  this  division  of  Class  II.  are  similar  to  those  just  shown 
in  the  full  <livision. 

Fig.  623  shows  the  profile  of  a  girl,  aged  thirteen,  whose  facial  lines 
were  thrown  out  of  balance  by  reason  of  mal-occlusion  of  Class  III., 
as  shown   in  Fig.  812.     A  very  superficial  study  of  the   mal-occlusion 


Fk..  r,-23. 


Fig.  62 1. 


is  sufficient  to  show  us  the   reason    for  the   flat  ujiper  lip  and  unnatural 
prominence  and  heaviness  of  the  chin  and  lower  lip. 

The  simple  application  of  our  rule  produced  the  result  in  facial  lines 
shown  in  Fig.  624,  and  in  occlusion  shown  in  Fig.  813, 


FACIAL  ART. 


705 


When  the  teeth  are  placed  in  conformity  to  the  plan  of  nature,  the 
lines  of  the  mouth  are  of  necessity  molded  into  the  most  harmonious 
that  human  effort  can  produce. 

Thus  far  we  have  considered  the  marring  effect  on  the  facial  lines 
resulting  from  mal-occlusion  when  the  normal  number  of  teeth  are 
present ;  but  there  is  another  phase  of  mal-occlusion  almost  if  not  quite 
as  common  and  equally  destructive  to  the  balance  and  beauty  of  the 
face — namely,  the  lack  of  teeth  from  non-development  or  non-eruption, 
or  their  loss  from  extraction. 

The  loss  of  even  a  lateral  incisor  not  only  produces  great  inharmony 


Fig.  625. 


of  occlusion,  but  equal  inharmony  in  the  facial  lines.  Fig.  625  shows 
the  profile  of  a  young  lady  whose  upper  right  lateral  incisor  failed  to 
develop,  as  was  revealed  by  the  a;-rays,  and  the  resultant  inharmony  in 
the  relations  of  the  upper  and  lower  lips,  as  well  as  the  unpleasing 
angle  between  the  upper  lip  and  nose,  is  readily  seen.  It  can  be  imag- 
ined how  great  would  have  been  the  improvement  in  the  facial  lines 
had  that  tooth  developed  normally  and  the  upper  arch  been  enlarged  to 
accommodate  it. 

Since  this  is  true,  what  must  we  think  of  the  frequently  advocated 
practice  of  extracting  one  or  both  lateral  incisors  or  even  canines  in  the 
supposed  hope  of  relieving  crowded  conditions  of  the  teeth  ? 

The  profile  on  the  left  of  Fig.  626  shows  the  effect  on  the  facial 
lines  of  an  effort  to  prevent  mal-occlusion  by  the  extraction  of  the  per- 
fectly sound  four  first  permanent  molars  at  the  age  of  nine  years,  which 
is  in  keeping  with  a  belief  still  practised  by  many  of  the  old  school.     We 

45 


706 


ORTHODONTIA. 


need  possess  very  little  artistic  perception  to  readily  detect  the  great 
inharmony  of  the  mouth  with  the  other  features.  The  lack  of  balance 
is  so  pronounced  as  possibly  to  create  the  impression  that  all  the  teeth 
have  been  lost,  and  that  the  lady  is  wearing  badly  proportioned  artificial 
dentures. 

The  profile  on  the  right  of  Fig.  62(j  shows  the  facial  lines  restored 
to  normal  i)alance,  or  as  nearly  so  as  was  possible  at  that  age  of  the 
patient,  established  by  the  placing  of  the  teeth  that  remained  in  their 
normal  relations.  Fig.  772  shows  this,  and  the  case  ready  for  the  inser- 
tion of  artificial  substitutes  for  the  missing  molars. 

Fig.  626. 


Fig.  627  shows  the  profile  of  the  face  of  a  young  lady  where  extrac- 
tion of  l>oth  upper  first  premolars  was  resorted  to  by  the  writer  several 
years  ago  in  carrying  out  the  old  plan  of  treatment  for  the  reduction  of 
"labial  protrusion  of  the  upper  incisors,"  or  a  case  belonging  to  Division 
1  of  Class  II.  The  eifect  of  this  treatment,  instead  of  improving  the 
facial  lines,  especially  the  angle  of  the  nose  with  the  upper  lip,  was  to 
cause  their  greater  inharmony,  and  has  been  the  occasion  of  lasting 
regret. 

The  \vriter  wishes  to  indelibly  impress  on  the  mind  of  the  student 
that  since  normal  balance  of  the  lines  of  the  mouth  with  those  of  the 
other  features  is  dependent  on  the  normal  occlusion  of  the  teeth,  they  are 
necessarily  thrown  out  of  balance  and  out  of  harmony  just  in  proportion 


ETIOLOGY  OF  MAL-OCCLUSION. 


707 


as  the  teeth  are  out  of  normal  occlusion,  and  that  since  extraction  always 
produces  mal-occlusion  just  in  proportion  to  the  number  of  teeth  ex- 
tracted, where  mal-occlusion  did  not  previously  exist,  and  exaggerates 
and  complicates  it  where  already  existing,  its  effect  on  the  facial  lines  is 
inevitably  as  inharmonious,  not  to  say  deforming,  as  its  practice  is  unpar- 
donable. 

Extraction  is  further  discussed  in  the  section  on  Treatment. 

Fig.  627. 


Etiology  op  Mal-occlusion. 

Many  of  the  causes  which  are  operative  in  producing  mal-occlusion 
are  as  yet  very  imperfectly  understood.  Only  a  few  of  those  most  easily 
recognized  will  be  here  considered. 

Premature  Loss  of  Deciduous  Teeth. — The  deciduous  teeth  not  only 
perform  the  important  function  of  masticating  the  food  required  by  the 
child  up  to  the  period  of  their  normal  loss  and  their  replacement  by  the 
succeeding  permanent  teeth,  but  they  also  assist  in  a  mechanical  way  in 
the  development  of  the  alveolar  process,  and  probably  in  the  develop- 
ment of  the  jaw  as  well. 

The  permanent  teeth  being  larger  and  more  numerous  than  the 
deciduous,  the  greater  space  required  for  them  is  provided  principally  by 


708  OR  THOD  ON  TIA . 

the  lengtliening  of  the  lateral  halves  of  the  dental  arehes.  This  is  influ- 
enced largely  by  the  development  and  eruption  of  the  permanent  molars 
posterior  to  the  deeidnons  molars.  If  the  mesio-distal  diameters  of  the 
deeiduous  teeth  be  not  impaired  by  earies  and  the  teeth  remain  the  nor- 
mal period,  the  first  permanent  molar  in  taking  its  position  in  the  arch 
must  force  its  way  between  the  second  deciduous  molar  and  the  ramus  of 
the  jaw  if  below,  or  the  maxillary  tuberosity  if  above. 

Coincident  with  the  development  of  the  jaw,  the  deciduous  teeth  are 
carried  forward,  and  the  normal  mesio-distal  lengthening  of  the  process 
takes  place.  li\  however,  one  of  the  deciduous  teeth  be  prematurely 
lost,  as,  for  example,  the  lower  first  molar,  the  eruj)ting  permanent  molar 
will  exert  its  wedging  influence  only  distally  to  the  lost  tooth  ;  it  will 
occupy  a  portion  of  the  space,  and  will  not  cause  any  forward  movement 
of  the  anterior  teeth.  If,  meanwhile,  no  teeth  have  been  lost  in  the 
same  side  of  the  opposing  arch,  the  wedging  process  will  have  pushed 
forward  the  deeiduous  teeth  and  the  normal  development  will  have 
occurred.  There  will  thus  be  an  inecjuality  between  the  jaws  on  the 
affected  side,  with  the  establishment  of  mal-ocelusion.  And  this  is  not 
the  only  evil,  for,  the  space  occupied  by  the  lost  tooth  having  been  closed 
or  greatly  diminished,  the  eruption  of  the  succeeding  permanent  tooth 
(the  first  premolar)  will  be  prevented  entirely,  or  it  will  be  forced  into 
buccal,  or,  possibly,  lingual  occlusion,  as  in  Fig.  702.  The  shortened 
lateral  half  will  not  develop,  and  the  lower  arch  will  consequently  be 
smaller  than  normal,  which  must  result  in  protrusion  of  the  upper 
incisors  by  the  lower  lip  being  forced  beneath  them,  or,  as  we  have 
already  noted,  in  an  irregular  arrangement  of  the  teeth  in  the  upper  arch 
through  the  effort  of  nature  to  restore  harmony  in  the  sizes  of  the  two 
arches  by  lip  pressure,  with  a  corresponding  inharmony  of  the  facial  lines. 

AVhih^  probalily  the  greatest  harm  results  from  the  premature  loss 
of  the  second  deciduous  molar  or  canine  in  either  arch,  the  principle 
applies  to  the  loss  of  any  of  the  deciduous  teeth,  the  difference  being 
only  in  degree. 

The  mechanical  influence  of  the  deciduous  teeth  in  the  development 
of  the  dental  arches  is  so  important  that  they  shoidd  not  only  by  all 
means  be  retained  their  full  normal  period,  but,  if  they  become  affected 
by  caries,  their  full  mesio-distal  diameters  should  be  restored  by  suitable 
fillings  after  sufficient  separation.  Likewise,  if  a  deciduous  tooth  be 
lost  through  the  premature  absorption  of  its  root,  the  full  space  occupied 
by  it  should  be  maintained  by  some  suitable  retaining  device. 

Prolonged  Retention  of  Deciduous  Teeth. — One  or  more  of  the 
deciduous  teeth  are  occasionally  retained  beyond  the  normal  period.  In 
this  event  the  succeeding  tooth  will  either  be  prevented  from  erupting 
or  will  be  deflected  to  a  malposition. 


ETIOLOGY  OF  MAL-OCCLUSION.  709 

Loss  of  Permanent  Teeth. — What  has  already  been  stated  in  regard 
to  the  mechanical  influence  of  the  deciduous  teeth  in  assisting  the  nor- 
mal development  of  the  dental  arches  and  promotion  of  harmony  of  the 
facial  lines  is  equally  applicable  to  the  permanent  teeth  up  to  the  period 
of  their  full  eruption,  or  until  the  last  of  the  molars  have  taken  their 
positions.  This  is  a  point  of  such  importance  that  it  should  be  carefully 
considered  by  all  teachers  and  students.  If  one  or  more  of  the  per- 
manent teeth  anterior  to  erupting  molars  be  extracted,  the  wedging 
process,  so  necessary  in  developing  the  arch,  serves  only  to  close  the 
space  thus  made,  and  there  will  be  no  carrying  forward  of  the  teeth  and 
process.  The  evil  effects  already  enumerated  as  arising  from  unequal 
development  of  the  two  arches  will  follow.  It  should  also  be  borne  in 
mind  that  the  interdependence  of  the  teeth  is  so  great  at  all  times  that 

Fig.  628. 


the  loss  of  one  or  more  at  any  period  in  their  history  must  have  a  marked 
influence  on  the  remaining;  teeth. 

Tardy  Eruption  of  Permanent  Teeth. — It  occasionally  happens  that 
a  tooth,  with  or  without  apparent  cause,  fails  to  erupt,  and  remains 
imbedded  in  the  alveolar  process  for  months,  or  even  years.  Usually 
the  space  is  partially  or  wholly  closed  by  the  adjoining  teeth.  The  impac- 
tion of  the  canine  is  the  most  common  of  any  of  the  teeth,  owing  to  the 
fact  that  it  erupts  after  both  its  mesial  and  distal  associates,  and  must  in 
all  cases  meet  more  or  less  resistance  from  them.  If,  later,  efforts  toward 
eruption  occur,  the  tooth  must  necessarily  be  deflected,  or  force  other 
teeth  into  malposition. 

Supernumerary  Teeth. — Supernumerary  teeth,  as  their  name  implies, 
are  anomalies,  or  extra  teeth  above  the  normal  number  of  thirty-two.  In 
outline  they  rarely  resemble  any  of  the  typical  tooth  forms,  being  most 


710  ORTHODONTIA. 

coiniiumly  peg-shaped  or  conical.  AltlioiiLjIi  tlicy  may  erupt  in  any  part 
of  the  dental  arches,  or  even  nearly  cover  the  entire  vault  ot"  the  upper 
arch,  as  shown  in  a  model  in  tlu;  writer's  collection,  and  also  in  two  or 
three  other  well-known  cases,  their  favorite  location  is  between  the  cen- 
tral incisors,  in  the  region  of  the  laterals,  or  in  the  hucco-embrasiai 
spaces  between  the  molars.  The  reason  for  their  appearance  is  not  clearly 
established. 

Habits. — The  habit  of  sucking  the  thumb,  lip,  or  tongue,  so  fre- 
quently formed  l)y  young  children,  while  rarely  causing  displacement  of 
the  deciduous  teeth,  will,  if  persisted  in  during  the  eruption  of  the  per- 
manent incisors,  cause  their  marked  mal-occlusion. 

In  the  case  of  thumb-sucking,  fortunately,  the  habit  is  usually  broken 
before  any  marked  evil  effects  result,  so  that  cases  where  mal-occlusion 

Fig.  629. 


has  really  resulted  from  this  habit  are  rare  and  easily  recognized.  The 
upper  incisors  and  canines  are  always  drawn  forward  and  to  one  side, 
according  as  the  thumb  of  the  right  or  left  hand  has  been  used,  while 
pressure  from  the  back  of  the  thumb  upon  the  lower  incisors  causes  their 
marked  displacement  lingually.  These  cases  are  frequently  confounded 
with  those  of  protrusion  belonging  to  Division  1  of  Class  II.  The  condi- 
tions and  results  are  very  different,  the  latter  being  mouth-breathers,  the 
former,  never,  as  such  action  would  be  an  impossibility.  This  is  illus- 
trated in  the  difficulty  which  infants  experience  in  nursing  while  suffering 
from  temporary  obstruction  of  the  nasal  passages  resulting  from  coryza. 
The  pernicious  habit  of  i)iting  the  lower  lip,  or  pressing  the  occlusal 
edges  of  the  upper  teeth  against  its  outer  surface,  has  a  tendency  to  move 


ETIOLOGY  OF  3IAL- OCCLUSION. 


711 


the  upper  centrals  forward,  thus  lessening  their  natural  resistance  to  the 
narrowing  of  the  lateral  halves  of  the  arch. 

Such  a  case  is  shown  in  Fig.  628.  In  this  case  the  mal-occlusionwas 
easily  reduced,  but  the  habit  of  biting  the  lip  was  still  persisted  in  for  a 
period  of  nearly  two  years,  necessitating  the  continued  wearing  of  the 
retaining  device  for  that  length  of  time.  This  habit  is  more  common 
than  seems  to  be  generally  supposed,  is  often  extremely  difficult  to  over- 
come, and  probably  accounts  for  many  ultimate  failures  in  tooth  regu- 
lating. It  is  always  a  marked  accompaniment  of  cases  belonging  to 
Division  1  of  Class  II.  and  its  subdivision,  and  unless  it  be  overcome 

Fig.  630. 


and  the  normal  functions  of  the  lips  regained,  the  incisors  cannot  be  kept 
in  their  normal  positions. 

Another  habit,  though  quite  rare,  that  of  resting  the  tongue  between 
the  upper  and  lower  incisors,  produces  the  effect  shown  in  Fig.  629. 
The  pressure  upon  the  incisal  edges  prevents  full  eruption  and  holds 
the  teeth  in  infra-occlusion,  while  the  molars,  being  held  apart  much 
of  the  time,  lengthen  into  positions  of  supra-occlusion  from  lack  of 
resistance. 

Nasal  Obstructions. — When  there  is  normal  nasal  respiration  and 
normal  relations  of  the  dental  arches,  the  teeth,  and  the  muscles,  the 


712  ORTHODONTIA. 

conditions  are  such  as  to  perfectly  iii;iiiit:iiii  the  e(|iiilil)riiim  and  the 
mutual  support  necessary  to  the  normal  tievelopnient  of  the  teeth  and 
jaws.  Should  nasal  ol)strnetions  occur  in  the  developing  child,  induc- 
ing habitual  mouth-hreatiiiug,  immediately  the  equilibrium  is  disturbed, 
the  lips  and  muscles  are  placed  on  a  different  tension,  an<l  pressure 
upon  the  arches,  instead  of  being  equal,  is  localized,  being  greater  than 
normal  at  some  points  and  less  at  others.  No  matter  how  strenuously 
it  may  be  denied,  mal-occlusiou  of  the  teeth  and  abnormalities  in  the 
formation  of  the  bones  of  the  jaws  naturally  follow.  The  uiidevelojx'd 
nose  and  adjacent  regit)n  of  the  face,  the  vacant  look,  the  short  upper 
lip,  the  open  mouth,  and  irregular  teeth  of  the  moutii-breather  are 
common  sights  familiar  to  all  (Fig.  630). 

Alveolar  Process  and  Peridental  Membrane. 

The  importance  of  a  thorough  knowledge  of  the  alveolar  process 
and  peridental  membrane  is  perhaps  greater  in  orthodontia  than  in  any 
other  branch  of  dentistry,  for  to  the  orthodontist  these  tissues  are 
secondary  only  in  importance  to  the  teeth  themselves;  and  it  is  largely 
owing  to  our  intelligent  comprehension  and  handling  of  these  tissues 
that  we  are  enabled  to  successfully  correct  malpositions  of  the  teeth. 
It  is  unnecessary  to  here  enter  into  an  extended  discussion  of  these 
structures. 

No  thoughtful  person  can  study  the  arrangement  of  the  fibres  of  the 
]x»ridental  meml)rane  Mithout  being  impressed  with  their  wonderful 
perfection  of  adaptation  for  resisting  the  various  tooth  movements  inci- 
dent to  occlusion  and  mastication,  and  a  knowledge  of  this  arrangement 
is  of  peculiar  interest  to  the  orthodontist,  enabling  him  to  better  com- 
prehend not  only  the  amount  of  force  required  and  difficulties  to  be 
overcome  in  moving  teeth,  but  the  necessary  anchorage  to  be  gained 
from  teeth  in  performing  the  operation,  as  well  as  a  far  better  insight 
into  the  problems  of  retention. 

Tissue  Changes  Incident  to  Tooth  Movement. — When  force  is 
exerted  upon  the  teeth  to  be  moved  two  principal  changes  take  place 
in  the  alveolar  process:  first,  a  bending  of  the  ])rocess  ;  second,  absorp- 
tion of  the  process  in  advance  of  the  moving  tooth  and  deposition  of 
bone  behind  it.  These  changes  vary  greatly  according  to  the  age  of 
the  patient,  in  different  patients  of  the  same  age,  in  the  direction  of 
movement,  and  also  in  the  rapidity  of  movement. 

In  youth,  or  before  the  bone  has  become  dense,  it  permits  of  much 
bending,  so  that  incisors  may  be  moved  out  of  inlock  in  a  few  hours, 
or  the  lateral  halves  of  the  arch  may  be  widened  in  a  very  few  days, 


ALVEOLAE  PROCESS  AND  PERIDENTAL  MEMBRANE.  713 

or  before  much  absorption  could  have  taken  place  in  advance  of  the 
moving  tooth.  In  further  proof  of  this  the  process  will  be  found  upon 
examination  to  be  intact  about  the  roots,  not  only  on  the  labial  side,  or 
in  front  of  the  moving  tooth,  but  on  the  lingual,  or  opposite,  side  as 
well,  it  having  been  dragged  after  the  moving  tooth.  This  is  easily 
explained  when  we  remember  the  cancellous  structure  of  the  bone,  the 
inelasticity  of  the  fibres  of  the  peridental  membrane,  and  their  very 
strong  attachment  to  it. 

While  more  or  less  springing  of  the  bone  is  probably  always  an 
accompaniment  of  tooth  movement,  yet  in  proportion  as  the  bone 
becomes  dense  with  age,  so  the  modification  of  the  process  attendant 
upon  tooth  movement  changes  from  springing  to  the  slower  action  of 
absorption  and  the  still  more  slow  deposition  of  bone. 

Coincident  with  the  changes  in  the  bone  there  are  also  pronounced 
changes  taking  place  in  the  peridental  membrane.  As  force  is  exerted 
on  the  moving  tooth  the  membrane  is  compressed  in  front  of  it,  between 
it  and  the  wall  of  the  socket,  while  a  greater  tension  of  the  fibres  of 
the  membrane  takes  place  on  the  opposite  side.  As  a  result  of  this 
tension  and  compression  the  nerves  of  the  membrane  are  impinged 
upon,  causing  a  greater  or  less  sense  of  pain,  which,  as  a  result  of  the 
slight  movement  of  the  tooth  and  temporary  paralysis  of  the  nerves 
from  pressure,  subsides  more  or  less  quickly  according  to  the  amount 
of  inflammation  present. 

As  a  result  of  this  pressure  the  absorbent  cells,  or  osteoclasts,  are 
stimulated  to  increase  in  number  and  activity.  They  immediately 
engage  in  the  absorption  of  the  portion  of  bone  most  involved  in  the 
movement,  as  well  as  of  the  bone  attachments  of  the  fibres  on  greatest 
tension. 

While  these  changes  are  taking  place  the  osteoblasts  have  become 
active,  and  have  begun  filling  up  the  depression  and  reattaching  the 
fibres  by  the  redeposition  of  bone.  But  as  this  is  a  much  slower  process 
than  that  of  absorption,  the  tooth  is  found  to  be  more  or  less  loose  in 
its  socket  at  the  completion  of  its  movement,  as  well  as  long  after, 
necessitating  its  being  supported  by  means  of  the  retaining  devices 
until  the  deposition  of  bone  shall  be  complete  and  a  perfect  socket 
reformed  for  its  support  in  its  new  position. 

If  a  tooth  be  elevated  in  its  socket,  the  principal  change  involves 
the  peridental  membrane.  The  fibres  at  the  end  directly  resisting  this 
movement  are  severed,  and  the  oblique  or  suspensory  fibres  are  stretched 
and  recurved  upon  themselves.  The  result  of  the  partial  withdrawal 
of  the  conical  root  is  increased  space,  not  only  at  the  end,  but  also  on 
the  sides  of  the  root,  so  that  there  is  considerable  freedom  of  movement 


714  ORTHODOSTIA. 

of  the  tooth,  nooessitatiug  the  deposition  ol"  hone  over  the  entire  surface 
of  its  socket,  as  well  as  increase  of  height  of  margin  and  a  reorganiza- 
tion of  the  entire  system  of  fihres.  This  explains  the  necessity  for 
such  protracted  suspensory  retention,  and  the  comparative  ease  with 
which  the  movement  may  be  performed. 

In  the  movement  of  depression — the  most  difficult  tooth  movement 
— the  bone  must  be  absorbed  by  the  osteoclasts  over  the  entire  surface 
of  the  alveolus  to  allow  for  the  advance  of  the  root  of  conical  form. 
The  fibres  of  lateral  support  are  stretched  and  placed  on  different 
angles,  while  the  suspensory  fibres  are  also  stretched  and  severed  at 
their  points  of  attachment  to  the  bone,  thereby  necessitating  more  dis- 
turbance of  tissues  and  requiring  more  force  and  time  than  any  other 
of  the  seven  movements. 

In  the  rotation  of  a  tooth,  as  probably  most  of  the  fibres  indirectly 
tend  to  prevent  the  tooth  from  turning  in  its  socket,  and,  in  addition, 
there  are  an  unusual  number  at  the  four  angles  so  arranged  as  to 
directly  resist  such  action,  little  springing  or  bending  of  the  process  is 
probable,  the  principal  change  being  the  absorption  of  the  fibres  and 
bone  involved  along  the  entire  length  of  the  root,  thus  accounting  for 
the  great  force  necessary  for  performing  this  movement. 

In  all  cases  of  tooth  inoveinent  a  large  number  of  the  fibres  of  the 
membrane  remain  on  tension  long  after  the  movement  is  complete,  the 
force  they  exert  tending  to  draw  the  tooth  back  to  its  original  position, 
thus  necessitating  considerable  support  from  the  retaining  devices  until 
the  tissues  have  become  thoroughly  re-established  in  harmony  with  the 
tooth  in  its  new  jiosition. 

In  accomplishiug  the  movement  of  teeth  lingually,  labially  (or  buc- 
cally),  mesially  or  distally,  the  principal  change  is  in  the  position  of  the 
crown  of  the  tooth,  it  being  tipped  into  its  correct  position.  The  usual 
supposition  is  that  the  tooth  in  the  alveolar  process  acts  as  a  lever, 
the  crown,  or  long  end  of  the  lever,  moving  in  one  direction,  and  the 
apex  of  the  root  in  the  opposite  direction.  To  make  clear  these  sup- 
posed changes,  and  especially  the  extent  of  the  movement  of  the  apex, 
writers  have  frequently  used  the  illustration  of  a  post  driven  about  one- 
third  its  length  into  the  earth.  If  force  be  exerted  at  right  angles  to 
a  side  of  the  post  near  its  top,  the  post  will  act  as  a  lever  in  the  dis- 
placement of  the  soil,  the  two  ends  of  the  lever  moving  in  opposite 
directions,  and  the  pivotal  point  being  somewhere  near  the  beginning 
of  the  last  third  of  the  imbedded  portion. 

The  illustration  is  a  poor  one  and  very  misleading,  as  the  mechanical 
conditions  are  very  different.  Doubtless  this  would  be  the  result  if 
the  tooth,  like  the  post,  had  but  one  resistant  substance  and  that  equally 
distributed  in  all  directions  about  its  root,  but,  as  is  shown  by  a  study 


ALVEOLAR  PROCESS  AND  PERIDENTAL   MEMBRANE.  715 

of  the  alveolar  process,  the  bone  varies  greatly  in  thickness  over  dif- 
ferent portions  of  the  root  and  in  different  teeth,  so  the  amount  of  dis- 
placement of  the  apex  of  the  root  of  a  tooth  depends,  oftentimes,  upon 
the  location  and  the  movement  of  the  tooth,  and  whether  one  tooth  or 
a  number  in  the  same  region  are  being  moved  in  the  same  direction. 
In  reality  there  may  be  little  or  no  displacement  of  the  apex,  or  there 
may  be  considerable. 

In  the  first  place  the  alveolar  process  is  not  a  level  plane,  like  that 
in  which  the  post  is  implanted,  but  a  projection  or  high  ridge,  of  elastic 
structure,  and  admits  of  some  bending  laterally,  its  susceptibility  to 
this  action  increasing  proportionately  as  we  approach  the  top.  The 
pronounced  bending  of  the  process  is  a  matter  of  common  observation 
in  efforts  at  extraction. 

Again,  the  mechanical  difference  in  the  attachment  of  the  post  to 
the  soil  and  the  tooth  to  the  alveolar  process  is  such  as  to  still  further 
add  greatly  to  the  difference  in  the  results  of  their  respective  movements. 
As  the  apex  of  the  root  is  implanted  deeply  in  the  bone,  which  is  greatly 
thickened  in  its  lingual  direction  and  reinforced  by  the  strong  cortical 
layer  of  the  alveolar  process,  its  movement  lingually  could  not  well 
take  place  as  a  result  of  springing.  This  movement  is  further  strongly 
resisted  by  the  innumerable  inelastic  fibres  that  encapsule  the  apex, 
radiating  in  all  directions  for  its  firmest  possible  attachment  to  the  bone, 
their  ends  being  enclosed  in  its  structure. 

So  in  the  labial  movement  of  the  crown,  the  lingual  movement  of 
the  apex  of  the  root  is  not  only  resisted  by  the  bone  in  front,  but  also 
behind  and  on  eacli  side,  by  reason  of  its  attachment,  while  with  the  end 
of  the  post  little,  if  any,  resistance  is  offered  by  the  soil  behind  or  on 
either  side,  but  only  by  that  in  front. 

Another  difference.  The.  force  for  the  movement  of  the  post  is 
applied  remote  from  the  fulcrum,  while  the  force  exerted  on  the  tooth 
by  the  ligature  is  applied  close  to  the  fulcrum,  or  at  a  point  best  calcu- 
lated to  facilitate  the  bending  of  the  alveolar  process  in  the  labial 
direction. 

Again,  unlike  the  post,  several  teeth  may  be  associated  in  the  move- 
ment, which  adds  still  further  to  the  possibilities  of  the  labial,  as  well 
as  adding  correspondingly  to  the  impossibilities  of  the  lingual  move- 
ment of  their  apices. 

In  the  lingual  movement  of  incisors  there  is  often  considerable  labial 
movement  of  the  apices  of  their  roots,  owing  to  the  lesser  resistance 
offered  by  their  thin  covering  of  bone  and  the  much  greater  thickness  of 
bone  on  the  lingual  surfaces  of  the  roots.  This  result  is  often  noticed 
following  the  reduction  of  protruding  incisors,  as  in  cases  belonging  to 
Division  1  and  its  subdivision  of  Class  II. 


716  OHTUODOSTIA. 

In  the  similar  inoveim-nts  of  tlic  upper  cimiiu's  and  premolars,  prac- 
tically the  same  changes  in  the  positions  ot"  the  roots  follow. 

In  the  movement  buccally  of  the  upper  molars  there  is  bending  or 
absorption  of  the  outer  plate,  the  palatal  roots  are  elevated  in  their  sockets 
to  make  easier  the  tipping  of  the  crown,  with  probably  no  movement  at 
the  apices  of  the  buccal  roots,  unless  it  be  that  they  are  forced  deeper  into 
their  sockets.  In  the  lingual  movement  of  the  same  teeth  there  is  more 
or  less  bending  of  the  process,  the  forcing  deeper  into  its  socket  of  the 
palatal  root,  with  perhaps  some  elevation  in  their  sockets  of  the  buccal 
roots. 

In  the  same  movements  of  the  lower  molars  there  is  greater  displace- 
ment of  the  apices  of  the  roots  in  tiie  opposite  dir(>ction  from  which  the 
crowns  are  moved,  owing  to  the  great  thickness  of  the  buccal  })late  of  the 
alveolar  process. 

In  tiie  movement  of  teeth  mesially  or  distal ly  there  can  be  little 
or  no  bending  of  the  labial  and  lingual  plates,  the  chief  resistance  now 
being  offered  by  the  septa  and  the  peridental  attachments,  and  the 
movement  of  the  teeth  more  nearly  resembles  the  movement  of  the  post, 
the  apex  moving  slightly  in  the  oj)posite  direction  from  the  crown,  as  in 
Fig.  678. 

The  Pulp. — Willie  th<>  l>ulp  of  tiie  tooth  is  a  tissue  more  or  less 
involved  in  tootli  movement,  when  the  operation  is  properly  performed 
this  tissue  is  practically  luidisturbed  and  should  suifer  no  real  injury. 
On  the  other  hand,  its  normal  function  may  be  so  interfered  with  as  to 
cause  it  to  suffer  marked  disturbance  and  even  complete  devitalization, 
especially  if  the  movement  be  conducted  too  rapidly,  or  the  force  be  too 
abruptly  applied.  The  principal  danger,  however,  arises  from  conges- 
tion and  inflammation  of  the  tissues  of  the  apical  region,  causing  the 
partial  or  complete  strangulation  of  the  vascular  supply  to  the  pulp. 

In  view  of  these  facts,  it  should  be  our  aim  to  prevent,  so  iiir  as  pos- 
sible, all  tendency  toward  inflammation.  If  the  pulp  becomes  partially 
(!ongested,  as  is  usually  evinced  by  a  slight  change  in  color,  as  shown 
through  the  enamel,  and  by  sensitiveness  to  thermal  changes,  the  tooth 
should  be  allowed  to  remain  passive  for  several  days,  when,  usually,  these 
symptoms  will  subside.  The  writer  has  notified  several  instancies  where 
these  symptoms  have  been  markedly  manifest,  and  have  wholly  subsided 
under  palliative  treatment.  Sometimes,  however,  complete  devitalization 
will  follow,  and  while  the  death  of  the  pulp  under  these  conditions  is  to 
be  regretted,  the  consequences  are  not  of  sufficient  importance  to  occasion 
any  more  regret  than  when  devitalization  is  found  necessary  in  the  treat- 
ment of  teeth  for  caries. 

The  principal  evil  following  the  death  of  the  pulp  in  these  cases  is 
the  possible  permanent  discoloration  of  the  crown,  which  is  more  liable 


ALVEOLAR  PROCESS  AND  PERIDENTAL  MEMBRANE.         717 

to  follow  the  speedy  death  from  strangulation  than  the  slow  devitaliza- 
tion from  the  encroachment  of  caries.  For  this  reason,  whenever  com- 
plete devitalization  of  the  pulp  is  apparent,  it  should  be  immediately 
removed,  the  tooth  treated,  and  the  canal  filled  after  the  best  pre- 
scribed methods,  when  the  further  movement  of  the  tooth  may  be 
conducted  with  probably  no  greater  fear  of  inflammation  than  if  the 
pulp  were  intact. 

It  is  often  desirable  to  perform  tooth  movement  soon  after  the  erup- 
tion of  the  teeth,  or  at  a  time  before  the  root  is  fully  formed,  the  end  of 
the  root  then  having  a  broad,  funnel-shaped  opening.  If  the  movement 
be  intelligently  performed,  the  pulp  at  this  age  should  suffer  no  greater 
disturbance  than  when  the  root  is  fully  calcified.  In  fact,  there  is  less 
probability  of  strangulation  and  death  than  later,  when  the  foramen  is 
greatly  diminished  in  size. 

Physiolog-ical  Changes  Subsequent  to  Tooth  Movement. — So  far 
we  have  considered  the  physiological  changes  which  take  place  in  the 
tissues  during  tooth  movement,  but  we  must  remember  that  certain  very 
important  changes  also  occur  subsequent  to  tooth  movement.  To  better 
understand  these  changes  we  must  keep  in  mind  the  conditions  previ- 
ously existing.  The  development  of  mal-occlusion  is  gradual,  and,  in 
proportion  as  the  positions  of  the  teeth  deviate  from  the  normal,  a  corre- 
sponding deviation  is  necessitated  in  the  development  of  the  alveolar 
process,  and,  to  a  greater  or  less  degree,  in  the  bones  of  the  jaws,  vault 
of  the  arch,  the  nasal  tract,  and  the  muscles  of  the  face.  All  being  out 
of  harmony,  the  tendency  is  usually  to  favor  still  greater  inharmony,  or 
departure  from  the  normal,  as  growth  and  development  progress. 

After  the  crowns  of  the  teeth  have  been  moved  into  correct  positions 
in  the  line  of  occlusion  and  harmony  of  the  occlusal  planes  has  been  estab- 
lished, the  positions  of  the  teeth  and  function  of  the  occlusal  planes  have 
been  so  changed  as  to  exert  a  different  influence  upon  the  bones  and  mus- 
cles. The  tendency  now  is  to  assist  and  stimulate  nature  to  efforts  toward 
the  rearrangement  of  these  tissues  and  their  normal  growth  and  develop- 
ment, in  accordance  with  the  demands  of  the  teeth  in  their  new  positions 
and  with  her  original  design.  Evidences  are  common  throughout  sur- 
gery of  nature's  wonderful  inherent  power  to  remedy  her  defects,  and 
of  her  prompt  response  as  soon  as  favorable  conditions  for  self-assertion 
have  been  established.  The  natural  changes  following  the  intelligent 
correction  of  mal-occlusion  are  often  pronounced  and  gratifying. 

The  cognizance  of  the  possibilities  of  these  changes  should  in  many 
instances  modify  our  plan  of  treatment  from  what  it  would  be  were 
we  ignorant  of  them.  Very  frequently  where  there  has  been  change 
of  position  of  a  number  of  teeth,  especially  in  both  arches,  some  may 
occupy  planes  of  greater  elevation  than  others,  or  the  cusps  of  some 


718 


ORTHODONTIA. 


may  not  (ktuj)v  exaotly  normal  mesio-distal  relations;  hnt  if  wo  iiavc 
succet'ded  in  placing  the  teeth  so  that  tiie  inclined  planes  of  their 
occlusal  surfaces  favor  their  normal  positions,  their  proper  heights  and 
relations  will  gradually  become  estahlislied  as  a  result  of  occlusion.  In 
some  cases  the  incisors  may  ai)parently  l)e  much  too  short,  but  after  a  few 
weeks  or  months,  when  the  posterior  teeth  shall  have  become  settled  in 
their  new  positions,  the  U'ugth  of  overbite  of  incisors  will  be  normal. 

Another  noticeable  and  most  important  change  is  that  following  the 
movemi'iit  labially  of  the  crowns  of  a  number  of  incisors,  as  in  Fig. 
()31,  the  crowded  and  bunched  positions  of  the  incisors  have  pro- 
duced marked  arrest  in  the  development  of  the  alveolar  process  in  the 
region  of  their  apices,  so  that  after  correction  they  are  found  to  stand 
at  a  very  pronounced  angle,  with  an  abnormal  depression  in  the  region 
of  the  apices  of  their  roots  (Fig.  632),  and  an  apparent  overprominence 
of  the  lip,  often  suggesting  the  impossibility  of  their  being  maintained 
in  such  positions  and   the  desirability  of  extraction   in  order  to  reduce 

Flu.  i;;i.  I'k..  r,;!-j. 


this  prominence.  But  in  a  large  percentage  of  cases  the  apparent 
jirominence  is  due  to  lack  of  development  of  the  alveolar  process  and 
the  lingual  ])ositions  of  the  apices  of  the  roots,  wdiich  have  developed 
thus  in  accordance  with  the  demands  of  the  teeth  in  mal-occlusion. 

The  crowns  of  the  teeth  now  being  in  normal  occlusion,  nature  is 
stinnilated  to  continue  the  development  of  the  alveolar  })rocess,  and  to 
shift  labiajly  to  normal  ])ositions  the  apices  of  the  roots,  so  that  in  due 
time  there  will  be  the  full  normal  contour  of  the  alveolar  ])rocess  and 
the  teeth  will  stand  at  a  normal  angle,  the  result  being  a  corresponding 
itnprovement  in  the  contour  of  the  face  in  the  region  of  the  base  of  the 
nose — a  far  better  result  than  could  have  taken  place  had  extraction 
been  resorted  to. 

The  changes  here  outlined  are  shown  to  have  taken  ])lace  in  Fig. 
633,  which  represents  a  model  of  the  corrected  case  three  years  later 
than  that  shown  in  Fig.  632. 

The  discoverv'  of  th(>  fact  that  the  nutrition  of  the  structures  will 


'  Angle,  Malrocclusion  of  the  Teeth  and  Fractures  of  the  Maxilla;  sixth  i-dition. 


ALVEOLAE  PROCESS  AND  PERIDENTAL  MEMBRANE.         719 

• 

be  so  stimulated  as  to  develop  the  alveolar  process  and  actually  shift 
the  apices  of  the  roots  of  the  teeth  amounts  to  an  important  step  in  the 
evolution  of  this  science,  for  it  makes  inexcusable  the  sacrifice  of  teeth 
in  order  to  provide  room  in  the  arches  for  the  teeth  that  remain. 

It  is  well,  however,  to  remember  that  this  subsequent  development 
is  very  active  and  quick  to  respond  in  youth,  or  during  the  period  of 
eruption  of  the  incisors  and  for  some  years  later,  but  that  it  diminishes 
in  activity  in  proportion  to  the  age  of  the  patient,  until,  after  the  age 
of  maturity,  it  is  doubtful  whether  any  perceptible  filling  in  of  the 
bone  takes  place — another  strong  evidence  of  the  importance  of  the 
movement  of  teeth  in  early  youth. 

It  is  quite  probable  that  in  the  case  above  cited,  while  the  develop- 
ment of  the  alveolar  process  was  progressing,  a  change  in  the  positions 
of  the  crowns  of  the  teeth  of  both  arches  was  also  being  effected,  there 
being  a  slight  movement  distally  on  account  of  the  increase  of  lip 
pressure  due  to  the  more  prominent  positions  of  the  incisors.     This, 

Fig.  (333. 


however,  could  not  have  occurred  unless  there  had  been  full  normal 
function  of  the  lips,  accompanied  by  habitual  nasal  breathing. 

Again,  where  one  or  both  of  the  lateral  halves  of  the  upper  arch 
have  developed  with  the  teeth  in  lingual  occlusion,  the  result  is  to  pre- 
vent the  normal  development  and  width  of  the  arch,  as  in  Fig.  732. 

It  will  be  observed  that  force  incident  to  mastication  is  brought  to 
bear  upon  the  crowns  at  an  abnormal  angle  to  their  axes,  with  pro- 
nounced perversion  in  the  development  of  the  alveolar  process  and  of 
the  jaws,  abnormal  height  of  the  vault  of  the  arch,  and  greatly  marred 
facial  lines. 

Following  the  labial  tipping  of  the  crowns  of  the  upper  molars  and 
the  lingual  tipping  of  those  of  the  lower  arch,  the  force  of  occlusion 
will  be  received  at  the  proper  angle  with  the  axes  of  the  teeth,  or  prin- 
cipally upon  the  buccal  cusps  of  the  lower  inolars  and  lingual  cusps 
of  the  upper  molars.  In  this  case,  as  in  all  similar  cases,  marked 
changes  followed.     The  width  of  the  face  in  the  region  of  the  upper 


720  ORTHODONTIA. 

jaw  was  perceptibly  increased,  and  diniinisliod  in  that  of  the  lower, 
with  a  corresponding  improvement  in  the  vanlt  of"  the  arch  and  function 
of  the  nose,  which  continued  until  jirohahly  normal  proportions  were 
established. 

There  are  also  noticeable  changes  following  the  reduction  of  marked 
prominence  of  the  upper  incisors,  as  in  those  cases  belonwini:-  to  Division 
1  of  Class  II.  As  the  crowns  of  the  incisors  are  moved  lingually  the 
apices  of  the  roots,  as  we  have  already  noted,  are  moved  to  some  extent 
in  the  opposite  direction,  which  is  evinced  by  more  or  less  of  a  fluted 
appearance  of  the  alveolar  process  in  the  region  of  their  apices,  and  to 
some  extent,  a  greater  prominence  of  the  lij)  in  the  region  of  the  base 
of  the  nose.  But  if  normal  function  of  the  nose  and  lip  has  been 
established,  there  will  follow  a  return  of  the  apices  to  their  normal 
positions,  with  corresponding  normal  development  of  the  alveolar  process 
surrounding  them,  and  a  corresponding  lessening  of  the  prominence  of 
the  tissues  at  the  base  of  the  nose. 

Other  changes  following  tooth  movement  are  mentioned  in  connec- 
tion with  cases  discussed  under  Treatment. 

Models. 

The  first  step  in  tlie  study  of  all  cases  preparatory  to  treatment  is 
the  taking  of  accurate  impressions  of  the  teeth,  from  which  accurate 
articulating  models  of  both  arches  are  made.  Such  models  not  only 
assist  in  the  classification  and  diagnosis  of  cases,  but  also  aid  in  deter- 
mining the  proper  ])lan  of  treatment,  and  are  also  exceedingly  valuable 
for  reference  during  its  continuation,  for  by  comparing  the  models  with 
the  natural  teeth  at  each  visit  of  the  patient  we  may  not  only  keep  posi- 
tively informed  as  to  the  exact  movements  of  the  malposed  teeth,  but 
anv  unfavorable  movement  of  the  anchor  teeth  may  also  be  imme- 
diately detected.  Accurate  measurements  of  the  extent  of  movement 
of  any  tooth  or  teeth  may  also  be  made  at  any  time,  with  such  models 
as  a  basis. 

Material  for  Impressions. — Models  are  only  valuable  in  proportion 
as  thev  are  accurate,  and  the  only  models  approximating  accuracy  are 
those  made  from  plaster  impressions.  These  models  must  show  not 
only  both  arches  and  the  relative  positions  of  the  teeth  and  cusps,  as 
well  as  the  vault  of  the  arch,  rugae,  and  gums,  but  must  also  correctly 
show  as  much  of  the  roots  and  their  positions  as  are  indicated  by  the 
gums  and  alveolar  process  up  to  the  point  where  the  attachment  of  the 
muscles  renders  obscure  the  further  shape  of  the  jaw. 

Models  sufficiently  perfect  cannot  be  made  from  impressions  taken 
in  modelling  compound  or  other  of  the  plastics. 

The  shape  of  the  jaw,  together  with  the  shapes  and  inclinations  of 


MODELS. 


721 


the  teeth,  make  the  removal  of  a  plastic  impression,  without  change  of 
form,  impossible.  The  degree  to  which  arrest  of  development  of  the 
alveolar  process  has  taken  place,  especially  in  the  region  of  the  roots 
of  the  incisors,  so  important  to  accurately  record  in  the  model,  can  only 
be  the  merest  supposition  in  a  model  made  from  a  plastic  impression. 

Fig.  634. 


When  the  correct  method  of  taking  plaster  impressions  has  been 
learned  the  operation  occasions  but  little,  if  any,  more  trouble  to  the 
operator,  or  objection  from  patients  than  if  one  of  the  plastics  were 
used. 

The  Trays. — The   writer's  trays,  shown  in  Figs.  634  and  635,  are 

Fig.  635. 


best  suited,  being  much  higher  than  the  ordinary  trays.     In  taking  an 
impression  care  should  be  taken  to  select  a  sufficiently  large  tray,  which 
should  be  bent  to  conform   more   nearly  to  any  peculiarity  in  the  shape 
of  the  jaw;  this  will  not  injure  the  tray. 
46 


722 


ORTHODONTIA. 


Taking  the  Impressions. — (iood  impression  plaster  is  mixed  in  the 
usual  way  and  caretully  distributed,  as  shown  in  Fig.  636,  the  shape 
and  height  uf  the  trays  making  but  little  impression  material  neces- 
sary. It  will  be  observed  that  the  greater  amount  is  placed  in  the  ante- 
rior part  of  the  tray  and  made  to  extend  over  the  outer  edge  of  the  rim, 
none  being  allowed  in  the  vault  of  the  tray. 

It  is  now  placed  squarely  in  position  and  the  plaster  allowed  to  rest 
evenly  in  contact  with  the  occlusal  edges  of  all  the  teeth,  but  not  forced 
up  into  position.  The  lip  is  then  raised,  and  the  plaster  extending  outside 
of  the  rim  of  the  tray  is  carried  high  up  underneath  it  with  the  finger. 
This  is  to  insure  the  expulsion  of  air,  as  well  as  a  high  impression. 
The  tray  is  then  forced  up  evenly  until  the  points  of  the  teeth  touch,  or 
nearly  touch,  the  bottom  of  the  tray,  and  steadily  supported  upon  the 
end  of  the  index-finger  only.  To  expel  the  air  from  the  cheeks  they  are 
now  gently  manipulated,  but  not  drawn  down,  as  to  do  this  would  force 

Fig.  636. 


down  a  portion  of  the  plaster  and  prevent  one  of  the  important  objects — 
viz.,  a  very  high  impression. 

It  should  be  allowed  to  remain  in  position  until  the  plaster  has 
become  thoroughly  set,  which  is  very  important,  as  the  harder  the  plaster 
is  allowed  to  become,  the  more  perfect  will  be  the  impression. 

The  tray  is  now  loosened  and  taken  away,  leaving  the  impression  in 
the  mouth.  It  is  essential  that  the  tray  sliould  loosen  easily  from  the 
impression  ;  hence  the  importance  of  its  being  kept  clean,  bright,  and 
smooth. 

Two  grooves  are  then  scraped  or  cut  in  the  hardened  plaster  on  a 
line  parallel  with  the  canine  teeth,  but  not  cut  quite  through.  Then 
with  a  quick  pry  with  the  point  of  a  knife  the  anterior  plate  is  loosened. 
The  lateral  pieces  are  then  broken  off  with  the  thumb  and  finger,  when 
the  large  piece  covering  the  roof  of  the  mouth  alone  will  remain.  This 
may  be  readily  worked  loose,  and  if  the  operation  has  been  carefully 


MODELS. 


723 


performed  the  impression  will  consist  of  four  pieces,  although  to  have  a 
much  greater  number  would  in  no  way  injure  it. 

After  the  pieces  of  the  impression  are  dry  they  are  united  by  means 
of  wax,  and  should  present  the  appearance  illustrated  in  Fig.  637. 

This  method  of  taking  impressions  preserves  the  fine  points  of  the 
interdental  spaces.  We  believe  it  to  be  the  only  practicable  way  of  taking 
an  accurate  impression. 

In  like  manner  the  impression  of  the  lower  arch  is  taken,  removed, 
and  united,  being  careful  to  observe  the  essential  points — namely,  carry- 
ing the  impression  material,  which  has  been  built  up  and  outside  of  the 
anterior  part  of  the  rim  of  the  tray,  well  down  beneath  the  lip  with  the 

Fig.  637. 


finger  before  forcing  the  tray  home,  then  expelling  the  air  by  gradually 
working  the  cheeks  while  the  tray  is  steadily  held  by  the  ends  of  two 
fingers  of  the  left  hand,  one  to  rest  on  the  top  of  each  lateral  half. 

Varnishing-  the  Impression. — The  impressions  being  united,  they 
should  be  coated  very  evenly  with  shellac  varnish.  At  the  expiration 
of  half  an  hour,  or  when  the  varnish  has  become  hard,  a  second  coat 
should  be  applied  over  the  occlusal  surfaces  of  the  teeth  and  rough 
points  only,  not  over  the  smooth  surfaces,  especially  the  labial  gum  sur- 
faces. Dry  again,  and  then  apply  over  the  entire  impression  a  very  thin, 
even  coat  of  sandarac  varnish.^ 

^  It  is  important  that  both  of  these  varnishes  shall  be  of  the  proper  consistence,  which 
is  difficult  to  describe.  If  too  thin,  the  hard,  glossy  surface  will  be  wanting,  and  it  will 
be  difficult  to  separate  the  impression  without  injury  to  the  model.  If  too  thick,  all  fine 
tracings  of  the  impression  will  be  obliterated. 


724 


ORTHODONTIA. 


The  Models. — After  drying  for  bait'  iin  liour  the  impression  will  be 
ready  for  filling;,  which  may  be  best  aecomplislied,  in  order  to  insure 
expulsion  of  air-bubbles,  by  quickly  and  carefully  painting  the  plaster 
into  the  tooth-cavities  with  a  small  came  rs-hair  brush,  then  rapidly  fill- 
ing with  a  spatula,  gently  shaking  the  while  (never  jarring),  after  which 
it  should  be  turned  bottom  upward  on  a  glass  slab. 

After  the  plaster  has  thoroughly  set,  the  pieces  of  the  impres- 
sion may  usually  be  very  readily  separated  in  the  .same  order  in  which 
thev  were  removed  from  the  mouth.  Should  any  air-cavities  be  found 
in  the  model,  they  may  be  remedied  by  the  artistic  use  of  a  delicate 
brush  in  the  application  of  plaster  of  a  creamy  consistence.  A  cusp  or 
broken  tooth  may  in  like  manner  be  repaired. 

The  models  may  now  be  trimmed,  and  not  only  will  there  be  a  surface 
as  smooth  as  polished  marble,  but  each  cusp,  all  the  interdental  spaces, 
and   the  rugai,  as   well  as  the   inclinations  of  the   roots,  and  even  the 


Fig.  638. 


Model  plane. 

minute  "  .stipples "  of  the  gum,  and  the  developmental  lines  of  the 
enamel,  will  all  be  accurately  and  beautifully  shown.  Any  coating  of 
paint  or  varnish  only  detracts  from  the  beauty  of  such  models. 

The  models  should  be  trimmed  according  to  lines  of  graceful  propor- 
tions and  arti.stic  balance.  Formerly  this  trimming  was  all  done  with  a 
knife,  and  the  proportions  judged  with  the  eye.  Now  the  finer  trimming 
is  easily,  quickly,  and  accurately  accomplished  by  means  of  the  model 
plane  and  combination  square,  .shown  in  Fig.  638.  The  use  of  a  plane 
for  this  work  was  first  suggested  by  one  of  my  students.  Dr.  F.  S. 
McKay,  but  those  procurable  were  almost  useless,  as,  on  account  of 
being  made  of  iron  and  rusting,  they  greatly  discolored  the  models. 
The  writer's  plane,  shown  in  the  engraving,  is  made  of  brass,  with 
blade  of  hard  bronze,  and  effectually  overcomes  this,  and  the  combining 
of  the  plane  and  rule  is  another  feature  of  great  convenience. 

After  they  are  trimmed,  the  models  should  be  carefully  compared 


MODELS. 


725 


with  the  natural  teeth,  and  the  occlusal  relations  indicated  by  two  or 
more  pencil  markings,  so  that  the  proper  points  of  contact  may  after- 
ward be  readily  found.  These  serve  the  purpose  much  better  than  any 
form  of  an  articulator. 

As  soon  as  the  teeth  have  been  completely  moved,  another  impression 
should  be  taken  and  models  made.  This  is  done  after  all  appliances 
have  been  removed  and  the  teeth  thoroughly  cleansed,  and  immediately 
previous  to  adjusting  the  retaining  devices.  These  models  are  valuable 
for  comparison  with  the  natural  teeth  during  the  period  of  retention,  as 
well  as  for  future  reference. 

It  is  also  of  advantage  to  have  "  study  models  "  occasionally  made 
during  treatment  and  retention  by  pressing  a  piece  of  softened  wax,  about 
three-eighths  of  an  inch  deep,  on  to  the  occlusal  edges  of  the  teeth,  to 
accurately  show  their  positions  and  such  appliances  as  may  be  upon 
them  only. 

Fig.  639. 


Fig.  640. 


A  collection  of  fine,  accurate  models  is  not  only  an  incentive  to  keener 
interest  and  better  work,  but  is  a  most  valuable  form  of  "  library  "  in 
itself,  in  which  many  valuable  phases  of  the  subject  are  recorded  that 
can  never  be  reduced  to  writing. 

Models  should  never  be  mutilated  by  the  fitting  of  bands  and  appli- 
ances. While  they  may  serve  as  a  basis  for  general  measurements  for 
the  appliances,  the  fitting  should  always  be  done  to  the  natural  teeth. 

Photographs. — Quite  as  important  as  models  are  good  photographs 
of  the  patients'  faces,  in  which  are  represented  full  profile  and  front 
views  in  a  simple,  natural  pose.  These  are  far  preferable  and  more  relia- 
ble in  judging  the  harmony  and  inharmony  of  the  patient's  face  than  is 
the  plaster  cast  of  the  face. 

Skiagraphs. — Skiagraphs,  now  so  easily  and  quickly  made,  are  often 
of  great  value  in  settling  all  doubts  as  to  whether  teeth  be  missing,  or 


726  ORTHODONTIA. 

their  exact  locations  aiul  forms  if  merely  imhedded.  ^\'l^ile  these  points 
may  be  determined  in  the  majority  of  eases  i)y  careful  inspection  of  the 
contour  of  the  alveolar  j)roeess,  and  dii^dtal  pressure,  together  with  the 
use  of  the  exploring  neeille,  yet  where  any  doubt  exists  the  skiagraph 
should  be  resorted  to.  Fig.  639  illustrates  a  case  as  revealed  by  the 
skiagraph  where  the  canine  is  so  deeply  imbedded  in  the  alveolar  process 
as  to  baffle  the  ordinarv  methods  of  diairnosis. 

Fig.  640  shows  the  rare  case  of  a  missing  permanent  canine,  the 
deciduous  canine  being  nearly  ready  to  drop  out,  its  root  having  been 
almost  wholly  absorbed.     The  first  premolar  is  about  to  erupt. 

Where  any  doubt  exists  on  these  points,  the  a'-ray  should  promptly 
be  employed  to  eliminate  all  guessing,  so  that  we  may  positively  know 
exactly  what  conditions  exist. 

Regulating  Appliances. 

Two  plans  are  now  followed  in  the  designing  and  constructing  of 
regulating  appliances,  the  first  based  upon  the  belief  that  each  case  so 
radically  differs  from  all  other  cases  that  an  appliance  must  be  invented 
and  constructed  from  raw  material  to  meet  its  special  requirements. 
The  second  plan  recognizes  the  division  of  mal-oeelusion  into  a  few 
clearly  defined  classes,  having  requirements  of  treatment  clearly  indi- 
cated, with  fixed,  standard  forms  of  ready-made  regulating  appliances 
acting  upon  definite  principles,  which  amply  ])rovide  for  all  require- 
ments of  all  cases  belonging  to  each  class. 

The  'first  plan  is  the  one  which  has  been  most  universally  employed, 
and  has  come  down  to  us  from  the  earliest  history  of  orthodontia ; 
indeed,  much  of  the  literature  of  the  science  consists  of  descriptions 
of  appliances  which  have  been  invented  to  accomplish  tooth  movements 
in  special  cases,  until  some  thousands  are  recorded,  one  author  alone 
boasting  of  many  hundred.  AVhere  something  may  be  accomplished  in 
the  following  of  this  plan,  it  should  require  no  argument  to  prove  that 
there  are  many  reasons  why  it  is  most  defective  and  unscientific. 

First,  it  necessitates  that  each  dentist  shall  be  an  inventor,  and  it  is 
well  known  that  the  inventive  faculty  is  rather  a  natural  gift  than  an 
acquirement,  and  that  it  can  be  exercised  successfully  only  by  a  very 
few.  Then,  as  all  inventions  if  perfected  must  be  experimented  with, 
it  must  follow  that  each  case  so  treated  must  be  largely  in  the  nature 
of  an  experiment,  often  necessitating  many  changes  in  the  plan  and 
construction  of  appliances.  Hence  all  treatment  upon  such  theory  must 
be,  and,  in  fact,  has  ever  been,  tedious  and  costly,  and  often  of  doubtful 
result. 

Second,  another  objection  is  that  in  following  this  plan,  the  construc- 
tion of  appliances  must  necessarily  be  more   or  less  crude  and  lacking 


REGULATING   APPLIANCES.  727 

in  requisite  proportions,  for  any  instrument  only  reaches  perfection  as 
to  size,  proportion,  temper,  strength,  and  finish  after  much  experiment- 
ing and  repeated  efforts  toward  perfection  in  manufacture. 

Finally,  another  objection  more  serious  than  all  is  that  as  the  plan 
is  empirical,  with  only  a  vague  and  indefinite  basis  from  which  to 
reason,  the  difficulties  in  teaching  and  practice  become  very  great  and 
the  results  greatly  limited.  After  a  life  of  practice  the  dentist  follow- 
ing this  plan  must  still  be  in  a  maze  of  experiments,  and  unable  to 
impart  much  information  that  could  be  of  assistance  to  those  who  may 
begin  the  practice  after  him. 

The  second  plan,  as  we  have  already  stated,  recognizes  the  practi- 
cability of  fixed,  standard  forms  of  devices  for  the  requirements  of 
tooth  movement  necessary  in  all  the  various  classes  of  mal-occlusion, 
the  proper  forms  having  been  arrived  at  as  a  result  of  careful  experi- 
mentation and  close  observation  in  a  very  large  number  of  cases 
embracing  the  greatest  variety  of  mal-occlusion.  Instead  of  hand-made 
productions  by  the  dentist,  which,  with  his  limited  experience  and 
meagre  facilities,  must  always  fall  far  short  of  the  ideal,  they  are,  like  fine 
watches,  made  upon  elaborate  machinery  by  the  most  skilful  workmen. 

If  such  appliances  are  practicable,  it  must  become  apparent  to  all 
thoughtful  minds  that  the  advantages  from  their  use  must  be  very  great 
over  the  first  plan,  for,  instead  of  being  confronted  with  a  confusing 
and  almost  limitless  number  of  devices,  which  can  at  best  only  serve 
as  general,  vague,  and  often  delusive  patterns  to  him,  the  student  has 
but  to  thoroughly  familiarize  himself  with  a  few  standard  devices  which 
he  may  quickly  and  easily  apply. 

Again,  familiarity  with  and  repeated  use  of  standard  appliances  add 
greatly  to  the  possibilities  of  development  of  skill  and  judgment  in 
their  use,  as  in  the  case  of  the  frequent  use  of  favorite  patterns  of 
pluggers  or  excavators  which  have  also  been  made  by  skilled  experts. 
And  whether  or  not  ideal  standard  regulating  appliances  have  yet  been 
reached,  the  possibilities  and  positive  advantages  of  the  principle  over 
the  first  plan  are  so  marked  that  we  think  all  teachers  who  are  inter- 
ested in  this  branch  should  make  effi:)rt  toward  that  direction,  rather 
than  to  assist  in  perpetuating  a  principle  so  obviously  defective  that  it 
must  be  apparent  to  all  that  it  is  a  positive  hindrance  to  the  real  prog- 
ress of  orthodontia. 

It  is  now  well  known  that  most  of  the  real  progress  that  has  been 
made  in  dentistry  and  surgery,  and,  we  may  add,  in  orthodontia,  has 
been  since  the  dentist,  surgeon,  and  orthodontist  were  relieved  of  this 
impractical  task  by  experts  who  have  produced  instruments  so  perfect 
in  design,  construction,  and  finish  as  to  be  often  in  advance  of  their  com- 
prehension and  skill. 


728  ORTHODONTIA. 

The  writer's  appliaiiccs,  tlie  description,  plan  of  adjustment,  and 
operation  ol"  wliicli  will  he  i^iveii  llirtlier  on,  are  in  direct  keeping  with 
the  second  j)lan  just  described. 

Materials  for  Construction. — The  materials  that  have  hccn  used 
in  the  eonstriietion  of  devices  for  the  regulation  of  teeth  are  legion — 
gold,  silver,  platinum,  ))latinous  gold,  platinous  silver,  iridio-platininn, 
platinoid,  aluminum,  nickel  silver,  brass,  copper,  aluminum  bronze, 
st€el,  iron,  vulcanized  rubber,  India  rubber,  wood,  silk,  hemp,  gut,  and 
many  combinations  of  these  materials  have  all  been  used.  None  are 
ideal,  yet  most  of  them  possess  properties  of  more  or  less  value.  After 
years  of  experimenting  *  the  writer  is  convinced  that  the  material  most 
nearly  filling  all  requirements  is  nickel  silver.' 

Since  its  introduction  by  the  writer  some  eighteen  years  ago  for  the 
manufacture  of  regulating  appliances,  it  has  largely  supplanted  all  other 
metals  for  this  purpose.  Its  great  practical  value  becomes  more  and 
more  a))parent  with  familiarity  in  its  use.  It  is  very  susce])tible  of 
skilful  working,  and  may  be  developed  to  possess  great  strength  and 
rigidity,  or  it  may  be  given  great  elasticity.  When  properly  annealed 
it  is  very  malleable,  yet  sufficiently  rigid  to  give  it  the  excellent  work- 
ing qualities  so  necessary  in  retention  and  in  reinforcing  anchorage. 
Rolled  into  a  flat  ribbon,  if  it  be  of  the  proper  quality  and  properly 
treated  in  manufacture,  it  may  be  drawn  by  the  band-forming  pliers  so 
tightly  about  a  tooth  as  to  conform  to  its  surface  with  great  accuracy, 
even  though  it  be  but  three-thousandths  of  an  inch  in  thickness,  and 
yet  it  will  be  sufficiently  rigid  to  withstand  driving  to  place  upon  the 
tooth  without  crimping  or  changing  form  if  care  be  used,  in  striking 
contrast  to  gold,  silver,  platinum,  or  other  metals  of  the  same  thickness 
used  for  this  purpose. 

Its  surfaces  are  readily  united  by  solder,  and  its  fusing-point  is  so 
high  that  any  of  the  various  grades  of  gold  or  silver  solder  may  be 
employed  without  fear  of  injuring  the  band  by  overheating,  if  care  be 
taken  and  the  proper  flame  used. 

So  slow  a  conductor  of  heat  is  it  that  the  excellent  method  of  sol- 
dering by  holding  many  of  the  pieces  with  the  fingers  may  be  employed,* 
again  in  sharp  contrast  to  the  other  metals  we  have  enumerated. 

It  is  susceptible  to  a  high  degree  of  polish,  which  should  always  be 
given  to  plain  bands  after  setting,  and  which  is  lasting  in  many  mouths. 
Sometimes  these  bands  will  assume  a  delicate  bronze-like  color,  pleas- 
ing in  appearance,  and  the  writer  has  known   of  their  being  worn  for 

'  Nickel  silver  is  an  alloy  of  copper,  nickel,  and  zinc,  prepared  in  varying  propor- 
tions, aocoifling  to  the  nse  for  which  it  is  intended. 

'  Intro(hiced  by  the  writer  in  the  fii-st  edition  of  his  work  entitled  The  Anr/le  System 
of  Rerfxilntion  and  Retention  of  the  Teeth. 


THE   WRITERS  APPLIANCES.  729 

three  years  with  no  change  of  color.  In  a  small  percentage  of  mouths, 
however,  they  do  become  discolored,  even  to  unsightliness.  This  fact 
has  given  rise  to  the  only  prejudice  we  know  of  against  the  use  of 
nickel  silver  for  regulating  appliances ;  but  this  objection  is  trivial  in 
view  of  its  many  points  of  superiority.  In  those  few  mouths  in  which 
discoloration  does  take  place,  however,  and  where  the  wearing  of  the 
bands  in  retention  for  a  long  time  is  necessary,  it  may  be  better  to  use 
platinized  gold  for  the  bands.  This  is  the  writer's  practice  in  occa- 
sional cases ;  but  if  the  orthodontist  will  insist  on  a  reasonable  degree 
of  cleanliness  on  the  part  of  the  patient,  occasionally  devoting  a  few 
moments  of  attention  to  the  cleansing  of  appliances  and  teeth  himself 
with  the  soft-rubber  disk  and  pumice,  there  will  be  little  occasion  for 
complaint. 

Again,  the  inexpensiveness  of  nickel  silver  brings  it  in  sharp  con- 
trast to  gold  and  platinum,  but  it  is  its  ideal  working  properties  and  not 
its  cost  that  makes  it  the  most  desirable  of  all  materials  thus  far  dis- 
covered for  the  construction  of  regulating  appliances. 

The  Writer's  Appliances. 

When  the  writer  first  brought  out  his  so-called  system  of  appliances 
mal-occlusion  was  yet  unclassified,  and  the  "  special  appliance  for  each 
case  "  method  of  treatment  was  the  only  one  taught  or  practised.  In 
an  attempt  to  reduce  the  chaos  of  regulating  appliances  that  cumbered 
the  literature  and  hindered  the  progress  of  orthodontia  to  something  like 
system  and  order,  these  appliances,  designated  as  sets  Nos.  1  and  2,  with 
a  few  auxiliary  parts,  numbering  some  twenty  in  all,  were  introduced. 
By  their  use  separately  and  in  combinations  it  was  presumed,  and  truly, 
that  tooth  movements  could  be  much  more  quickly  and  easily  performed, 
and  with  far  less  annoyance  to  the  patient,  than  by  means  of  the  neces- 
sarily crude,  clumsy,  and  frequently  very  inadequate  hand-made  metal 
devices,  or  the  far  more  undesirable,  painful,  and  filthy  vulcanite  plates, 
cribs,  etc.  With  the  greater  development  of  the  science,  however,  and 
especially  since  the  classification  of  mal-occlusion,  the  writer  has  gradu- 
ally dispensed  with  the  greater  part  of  even  these  few  appliances,  until 
at  the  present  time  he  uses  practically  but  one,  or  three  modifications 
of  a  single  principle.  This  principle  was  given  us  nearly  two  hundred 
years  ago  by  the  famous  French  dentist,  Fauchard,^  and  it.  has  since 
been  used  in  many  modified  forms.  It  is  now  known  as  the  expansion 
arch,  and  in  conjunction  with  clamp-bands  for  the  anchor  teeth,  and  the 
auxiliaries  of  plain  or  spurred  bands,  and  wire  and  rubber  ligatures, 
it  is  adequate  for  all  necessary  movements  of  all  teeth  in  each  arch 

^  Le  Chirurgien  Dentiste  ou  Traite  des  Dents,  Paris,  1728. 


7;J0 


ORTHODONTIA. 


s('j)ar:itely,  :is  in  ('lass  I.  cases,  or  for  the  simultaneous  movement  of  all 
teeth  in  botii  arches  when  used  in  connection  w  ith  the  Baker  anchorage, 
as  in  cases  belonjrinjj  to  Classes  II.  and  III. 

The  writer's  improvements  of  this  appliance  may  briefly  be  said  to 
consist  in  change  of  metal  (nickel  silver),  modification  of  form  and  pro- 
]>ortions,  delicacy  of  temper,  greater  length  of  threading  of  sides  for 
universal  adjustment  of  size,  in  the  material,  style,  and  proportions  of 
the  parts  entering  into  the  anchor  clamp-bands,  and  in  the  various  attach- 
ments, some  of  which  are  modified  and  others  newly  devised.  Important 
among  these  is  the  addition  to  the  clamp-band  of  the  long  tubular  sheath 
for  the  reception  of  the  entls  of  the  arch,  which   not  only  protects  the 

Fig.  641. 


cheeks  from  abrasion  by  the  threaded  portion  of  the  arch,  but  gives 
greater  stability  to  the  anchorage.  Still  others  deemed  very  important 
are  the  friction  sleeve  of  the  sheath  of  the  clamp-bands  and  extension 
flange  of  the  arch  nuts,  the  extension  rib  on  the  ribbed  arch,  the  sheath 
hooks,  for  use  in  the  Baker  anchorage,  and  last  and  most  important,  the 
brass-wire  ligatures,  descriptions  of  all  of  which  follow,  in  connection 
with  instructions  for  their  use. 

As  before  stated,  there  are  three  forms  of  the  expansion  arch.  Fig. 
641  represents  the  plain  expansion  arch  E,  which  is  a  very  elastic  round 
bar,  bent  to  conform  approximately  to  the  shape  of  an  ideal  dental  arch. 
The  sides  of  this  arch  are  threaded  and  provided  with  nuts,  which,  with 


THE    WRITERS  APPLIANCES. 


731 


the  threaded  portion  of  the  arch,  accurately  fit  the  smooth-bore  tubes  of 
the  X  and  D  bands.  One  end  of  these  nuts  is  elongated  to  form  an 
extension  flange,  which  accurately  telescopes  the  friction  sleeve  of  the 
sheaths  of  the  D  and  X  bands,  as  shown  in  the  engraving. 

This  form  of  nut  adds  another  truly  valuable  improvement  to  the  ex- 
pansion arch,  as  it  enables  us  to  make  the  exposed  part  of  the  nut 
very  short  and  compact,  at  the  same  time  giving  greater  length  of  thread 
and  consequently  greater  strength.  Its  greatest  value,  however,  is  that 
this  extension  flange  prevents  the  loosening  of  the  nut  by  unscrewing 

Fig.  642. 


from  friction  with  the  tongue  or  cheek — a  common  annoyance  since 
screw  devices  have  been  used  in  the  mouth.  This  improvement  is  also 
made  use  of  in  the  writer's  jack-  and  traction-screws. 

Fig.  642  shows  the  ribbed  expansion  arch  E,  a  later  modification  of 
the  arch  last  shown,  and  differing  from  it  only  in  that  it  is  provided  with 
a  delicate  rib  on  the  periphery  of  the  unthreaded  portion,  in  which  hook- 
like notches  are  to  be  made  at  desired  points  to  prevent  slipping  of  the 
wire  ligatures.  By  this  means  the  direction  of  force  on  the  moving  teeth 
is  accurately  controlled.    It  is  a  most  important  improvement  to  the  arch. 


732  ORTHODONTIA. 

Fiji;.  043  shows  the  third  funn  of"  tlic  arcli,  as  used  hv  the  writer, 
known  as  the  arcli  B.  It  is  a  smooth,  throadless  arch,  similar  in  form 
and  temper  to  th(>  plain  expansion  arch  E,  thoutrh  more  limited  in  nse. 
It  is  especially  designed  for  use  in  connection  with  the  Baker  anchorage, 

Fig.  643. 


having  a  sheath-hook  on  each  side  for  the  reception  of  the  rubber  liga- 
tures. 

These  little  sheath-hooks,  Fig.  644,  may  also  be  obtained  separately 
for  attachment  to  either  of  the  other  arches  whenever  it  may  be  desired 
to  employ  them  in  connection  with  the  Baker  anchorage. 

Fig.  644. 


Fig.  645  represents  six  adjustable  clamp-bands.  Nos.  1  and  2  are 
plain,  and  are  used  both  in  regulation  and  retention.  Nos.  3  and  4  are 
provided  with  strong-headed  pins  soldered  to  their  screw-heads.  These 
were  especially  designed  for  the  treatment  of  fractures  of  the  maxillae, 
for  a  consideration  of  which  the  student  is  referred  to  the  sixth  edition 

Fig.  645. 


of  the  writer's  work  on  Mal-ocdusion  of  the  Teeth  and  Fractures  of  the 
Maxilla;. 

The  X  and  D  bands  are  provided  with  smooth-bore  tubes  soldered  to 
their  sides,  into  which  the  ends  of  the  arches  and  the  extension  flange 


THE   WRITERS  APPLIANCES. 


733 


of  the  nuts  accurately  fit.     The  X  bands  are  for  bicuspids  and  the  D 
bands  for  molars.^ 

Fig.  646  shows  three  coils  of  band  material  from  which  plain  bands 
for  incisors,  canines,  or  even  premolars  may  be  made,  to  serve  as  mediums 


1^ 


of  attachment  to  the  arch  through  the  Avire  ligatures.  They  are  also 
very  largely  used  in  retaining  devices.  C  and  F  are  of  the  same  width, 
being  narrower  than  H,  and  F  and  H  are  of  the  same  thickness,  being 


Fig.  647. 


thicker  than  C.  C  is  used  only  where  a  very  thin,  delicate  band  is 
required.  F  is  used  where  a  stronger  band  is  needed,  and  has  much 
more  universal  use.     H  is  used  principally  for  canine  bands. 


Fig.  648. 


/ 


Fig.  647  represents  the  wire  G,  a  section  of  very  soft,  smooth  wire. 
For  the  making  of  spurs  on  bands,  for  the  attaching  of  ligatures,  or  for 
retention  it  is  indispensable.  It  is  also  used  for  reinforcing  anchorage 
and  for  the  moving  of  teeth,  the  latter  being  illustrated  in  Fig.  703. 

^  For  the  varying  sizes  of  molar  teeth  there  are  three  sizes  of  D  bands,  although  in  the 
writer's  practice  the  medium  size  alone  meets  all  requirements  of  the  permanent  molars. 
The  smaller  size,  however,  is  occasionally  demanded  on  the  deciduous  molars. 


734 


oirriioDoyriA. 


Fig.  648  represents  the  retaining  tubes  R,  wliiili  aro  used  in  detach- 
able connections,  in  rointoroing  anchorage,  in  retention,  etc. 

Fig.  649  represents  the  ligature  wire,  which  is  very  solt,  smooth, 
tough,  strong,  bright  wire,  especially  prepared  for  the  use  of  orthodon- 
tists. It  comes  in  three  sizes.  The  largest  size  is  the  preferable  one 
for  performing  most  tooth  movements.  The  medium  size  is  used  where 
so  great  Ibrce  is  not  required,  or  where  the  teetii  are  so  close  together 

Fig.  649. 


that  the  larger  wire  could  only  be  passed  between  them  with  great  diffi- 
culty. The  smallest  size  is  principally  used  to  hold  teeth  passively  to 
the  arch  after  their  movement  is  completed,  while  the  movements  of  other 
teeth  are  being  completed  l)y  means  of  the  heavier  ligatures.  It  is  also 
sometimes  used  in  connection  with  the  retaining  devices. 

Fig.  650  represents  rubber  for  wedges,  which  are   principally  used 
to  intensify  pressure  on  some   tooth  of  overprominence,  or  to  assist  in 

Frrj.  fi.'iO. 


yfe  IN.  WIDE 


Vie  IN.    WIDE 


■  ■■■   nil 

rotation.     Figs.   684   and  685   show    working   combinations  of   these 
appliances. 

The  follow^ing  appliances  are  those  which  the  writer  has  now  practi- 
cally eliminated  from  his  practice,  not  because  they  were  inefficient  to 
perform  the  tooth  movements  required  of  them,  but  because  they  were 
designed  to  act  locally,  so  to  speak,  or  only  upon  teeth  that  seemed 
"crooked,"  instead  of  to  operate  from  the  basis  of  occlusion,  and  hav- 
ing control  of  one  tooth  or  of  all  teeth  in  one  or  both  arches.  But,  as 
will  be  shown  later,  while  not  often  used,  they  are  still  so  necessary  for 
some  purposes  that  they  cannot  be  wholly  dispensed  with.  Their  uses 
will  be  described  later. 


THE   WRITERS  APPLIANCES. 


735 


Fig.  651  shows  the  jack-screw  E  and  J.  The  first  regulating  jack- 
screw  was  invented  by  Dr.  Dwindle,  of  New  York,  in  1848.  This 
invention  marked  two  important  steps  in  the  progress  of  this  science. 
First,  the  introduction  into  orthodontia  of  one  of  the  most  compact  yet 


Fig.  651. 


powerful  forms  of  mechanism  known  to  mechanics  for  exerting  force ; 

second,  the  beginning  of  fixed,  standard  forms  of  regulating  appliances, 

with    interchangeable    parts,  and    kept    in  stock  at  the  dental  supply 

houses.^ 

Fig.  652. 


Fig.  652  shows  the  traction-screw  A  and  D.  It  consists  of  a  shaft 
bent  sharply  at  right  angles  at  one  end,  the  other  end  threaded  and 
provided  with  an  extension-flange  nut  and  three  accurately  fitting  tubes 


Fig.  653. 


of  smooth  bore — one  long  one  with  friction  sleeve  for  the  accommoda- 
tion of  the  extension  flange  of  the  Inut,  and  two  short  ones,  D.  Since 
in  treatment  the  sacrifice  of  teeth  has  become  practically  unnecessary. 


Fig.  654. 


the  use  for  this  once  highly  regarded  appliance  is  greatly  limited,  yet  it 
is  still  valuable  on  rare  occasions. 

Fig.  653  shows  a  bundle  of  spring  levers,  of  four  different  sizes. 

^  The  writei-'s  jack-screw  was   invented  in   1886.     Transactions  Ninth  International 
Medical  Congress. 


736 


ORTHODONTIA. 


These  are  made  of  piano  wire,  on  account  of  its  snj)crior  elasticity; 
yet  because  of  its  tendency  to  raj)id  corrositui,  no  matter  how  heavily 
plated,  and  the  consequent  discoloration  of  the  teeth,  its  ordinary  use 
is  objectionable.  Piano  wire  still,  however,  has  its  uses,  though  less 
than  formerly. 

Fui.  655. 


The  traction  bar  A,  Fig.  654,  is  provided  with  a  standard  in  its 
centre,  which  has  a  socket  for  the  reception  of  a  delicate  ball  on  the 
centre  of  the  arch  B.  The  hooked  ends  of  this  bar  are  for  the  recep- 
tion of  heavy  elastic  bands  from  the  headgear,  as  shown  in  Fig.  655. 

The  headgear.  Fig.  656,  is  a  cap  of  silk  netting  laced  to  a  metal 


THE   WRWEES  APPLIANCES. 


737 


rim  and  covering  the  back  of  the  head,  for  the  even  distribution  of 
force  exerted  bj  the  heavy  elastic  bands.  This  cap  is  strong,  artisti- 
cally made,  and  is  very  neat  in  appearance.  It  is  non-collapsible  and 
may  be  easily  and  quickly  adjusted  to  fit  any  size  of  head. 


Fig.  656. 


E.H.A 


The  chin  retractor,  Fig.  657,  is  used  only  in  connection  with  the 
headgear.  It  is  made  of  aluminum,  is  light,  neat,  and  highly  polished. 
It  will  fit  in  all  cases,  as  it  is  only  necessary  that  the  fit  be  approxi- 
mately accurate.  A  layer  of  fresh  absorbent  cotton  should  always  be 
placed  between  metal  and  chin  each  time  it  is  adjusted. 

Fig.  657. 


Since  the  introduction  of  the  Baker  anchorage,  the  use  of  the  trac- 
tion bar  and  headgear,  which  but  a  short  time  ago  were  considered  not 
only  valuable  but  indispensable,  has  been  largely  superseded.  It  is, 
however,  still  occasionally  desirable  to  use  them  as  an  auxiliary  to  the 
Baker  anchorage,  and  for  this  reason  they  are  here  described, 
47 


■38 


ORTHODOyTfA. 


They  still  onil)raf^o  the  best  principU's  in  tlio  :ippHcation  of  occipital 
anchorage  ;  but  as  tliey  are  so  objectionabh'  in  aj)p('arance,  and  the  relin- 
(piishnient  and  roapplication  of  pressure  in  their  wearing  necessarily  so 
frequent,  it  is  with  real  pleasure  we  point  to  their  passing. 


Fh..  r.c.o. 


Fin.  658. 


The  use  of  the  Baker  anchorage  has  also  abiiost  entirely  superseded 
the  use  of  the  chin  retractor,  yet  it  has  one  use,  to  be  mentioned  under 
Treatment,  and  for  this  reason  it  is  still  retained. 

It  has  been  doubted  by  some  in  the  past  whether  these  appliances, 


THE   WRITER'S  APPLIANCES. 


739 


Fig.  662. 


being  so  few  in  number,  were  sufficient  to  meet  all  requirements  in  the 
correction  of  mal-occlusion.  They  are  now  so  widely  used  and  their 
efficiency  is  so  thoroughly  established  that  this  question  need  not  here 

be  discussed.  Not  only  are  they  ade- 
quate for  all  cases,  from  the  simplest 
to  the  most  complex,  within  the  range 
of  orthodontia,  but  their  saving  in 
time  and  expense  to  the  dentist  and 
in  discomfort  to  the  patient  are  qual- 
ities widely  appreciated.  Another 
advantage  is  the  ready  convertibility 
of  certain  of  the  parts  into  simple, 
delicate,  yet  very  efficient,  devices 
for  the  retention  of  teeth. 

Fig.  663. 


Tools. — For  uniting  the  different  parts  of  the  appliances  to  form 
the  various  combinations,  and  for  placing  them  in  position  upon  the 
teeth,  only  a  few  tools  are  necessary,  but  it  is  important  that  they 


740 


ORTHODONTIA. 


should     be    of    the    best     selection     and     some     of    them     of    special 
design. 

Fig.  6")<S  shows  tiie  writc^r's  soldering  pliers.  Thev  are  most  suit- 
able, their  delieate  proportions  and  peculiar  form  making  them  espe- 
cially suited  for  holding  bands  and  small  pieces. 


Fifi.  6*)4. 


Fio.  «fio. 


Fig.  659  shows  another  pair  of  pliers,  for  placing  pieces  of  solder  in 
position,  picking  up  small  pieces,  etc. 

The  writer's  band-forming  pliers  are  shown  in  Fig.  660.  These 
were  designed  especially  and  are  indispensable  for  band-making.  They 
are  also  very  useful   for  most  other  purposes  for  which  ordinlry  flat- 


THE   WRITER'S  APPLIANCES. 


741 


beaked  pliers  are  used,  and  are  provided  with  grooves  for  holding  the 
small  square  nuts  and  round  wire. 

A  good  pair  of  wire-cutters  is   essential.     The  style  shown  in  Fig. 
661  is  the  most  satisfactory  of  the  many  makes  that  the  writer  has  tried. 

The  writer's  regulating  pliers  are  shown  in  Fig.  662.     These  are  for 
lengthening  or  shortening  wire,  and  numerous 
other  uses — a  very  valuable  instrument. 

A  pair  of  scissors  for  trimming  bands,  clip- 
ping ligatures,  etc.,  is  shown  in  Fig.  663. 

The  How  pliers,  for  twisting  ligatures  and 
for  general  uses,  is  shown  in  Fig.  664. 


Fig.  666. 


Fig.  668. 


Fig.  667 


U 


An  ordinary  hand  mallet  and  band  driver  (shown  in  Figs.  665  and 
666)  are  also  requisite. 

The  two  wrenches  shown  in  Figs.  667  and  668  are  of  universal 
application  to  all  the  various  nuts  of  the  appliances ;  one,  a  short  single- 
end  wrench,  and  the  other  a  double-end,  or  right-and-left,  wrench  espe- 
cially designed  for  the  adjustment  of  nuts  of  the  clamp-bands  on  lower 


742 


ORTHODONTIA. 


Fig.  GG9. 


molars,  they    being    practically    inaccessible   to    the   use  of  a    straight 
wrench.     Both  are  made  of  steel,  nickel-plated  and  finely  finished. 

And  last,  and  very  important,  a  suitable  lamp  for  soldering.  The 
writer  prefers  the  Lane  blow  pipe,  shown  in  Fig.  0G9. 

Soldering. 

It  is  safe  to  say  that  no  one  will  ever  ac((uire  much  skill  in  ortho- 
dontia unless  he  attains  proficiency  in  soldering,  for  the  soldering  of 
bands  and  the  union  of  tubes  and  spurs  to  bands  is  of  such  frequent 
necessity  that  skill  in  soldering  in  orthodontia  is  as  essential  as  in  the 
making  of  crowns  and  bridges.  Efforts  have  been  made  by  some  to 
construct  regulating  and  retaining  appliaiu-es  so  that  all  unions  of  parts 

shall  be  effected  by  mechanical  attach- 
ments, as  screw-,  hook-,  or  clamp- 
joints.  The  result  is,  of  course,  need- 
less bulk,  useless  complexities,  and 
unnecessary  expense.  But  to  the 
thoughtful  observer  it  would  require 
no  argument  to  prove  that  such  at- 
tachments, beyond  certain  narrow 
limits,  are  impracticable,  and  that  a 
brazed  joint  is  far  stronger,  far  more 
comj)act,  cleanly,  and  inexpensive. 

The  soldering  required  in  ortho- 
dontia may  be  accomplished  almost 
instantly,  and  that,  too,  easily,  by  the 
operator  who  will  devote  a  little  time 
to  mastering  the  method  here  described. 
As  many  of  the  parts  of  these 
appliances  are  very  delicate,  it  is 
important  that  a  fine,  sharp,  steady 
flame  be  used  in  effecting  their  union 
bv  solder.  A  larjre  or  uneven  flame  would  injure  and  might  ruin 
them.  The  Lane  blowpipe  (Fig.  669),  operated  m  ith  the  ordinary  foot- 
bellows,  is  especially  well  suited  to  orthodontists,  as  it  produces  a 
beautiful,  delicate  flame  (Fig.  670)  of  most  intense  heat,  yet  under  the 
most  perfect  control,  while  both  hands  of  the  operator  are  left  free. 

Notwithstanding  that  many  ingenious  spring  clamps  and  other  devices 
have  been  invented  for  holding  such  small  work,  the  plan  introduced  by 
the  writer  is  far  preferable  in  most  cases.  It  consists  in  holding  the 
pieces  in  contact,  either  w^ith  the  fingers  or  pliers,  while  soldering.  The 
metal  of  which  these  appliances  are  made  is  most  favorable  for  solder- 
ing in  this  way,  it  being  so  poor  a  conductor  of  heat  that  most  of  the 


SOLDERING. 


743 


attachments  can   be  held  in  the  fingers  without  any  perceptible  com- 
munication of  heat  to  them,  provided  the  flame  be  suitable. 

Where  union  of  a  small  tube  with  a  band  is  desirable,  as  in  Fig. 
670,  the  tube  is  best  held  in  contact  with  the  band  and  flame  by  means 
of  some  delicate  instrument  that  will  absorb  but  little  heat.  One  of 
Gates'  nerve-drills  with  the  point  broken  off  is  nearly  ideal  for  this 

Fig.  670. 


purpose.     Where  two  small  tubes  are  to  be  united,  as  in  Fig,  671,  the 
pliers  may  be  used  for  supporting  one  of  them. 

This  method  of  soldering  is  not  difficult,  most  students  learning  it 
readily.  The  only  point  that  may  seem  at  all  difficult  to  the  beginner 
is  the  holding  of  the  pieces  in  fixed  position  just  at  the  time  the  solder 
is  congealing.     This  is  accomplished  by  touching  one  or  more  of  the 

Fig.  671. 


fingers  of  one  hand  with  those  of  the  opposite  hand,  as  in  Figs.  670 
and  671,  to  steady  them,  at  the  same  time  holding  the  pieces  gently,  not 
rigidly,  just  as  a  good  penman  holds  a  pen.  After  a  little  practice 
any  of  the  various  soldered  attachments  may  be  easily  and  quickly 
made. 

Where  the  end  of  a  small  tube  is  to  be  united  to  a  band,  it  is  best  to 
fuse  the  solder  upon  the  band,  then  hold  the  small  tube  by  means  of  the 


744  ORTHODOSTIA. 

straight  pliers  in  contact  with  the  suUier  ami  again  ap})ly  heat,  as  other- 
wise the  solder  will  usually  be  drawn  into  the  tube. 

The  solder  best  adapted  for  uniting  the  different  parts  of  these  appli- 
ances is  silver  solder,'  although  any  of  the  various  carats  of  gold  solder 
may  be  used  with  cream  of  borax  for  a  flux.  Never  use  more  solder 
than  is  necessary,  especially  in  all  small  attaeluncnts — just  enough  to 
make  the  union. 

Always  avoid  overheating.  Apply  just  sufficient  heat  at  the  right 
point  from  a  fine,  sharp  flame  to  thoroughly  fuse  the  solder.  In  every 
instance  avoid  heating  the  screws  or  nuts.  This  is  to  be  especiallv 
observed  with  the  jack-  and  traction-screws  and  the  arches  El  and  B,  as 
great  care  is  used  in  their  manufacture  to  preserve  their  stiffness  and 
strength,  and  this  fine  temper  would  be  ruined  l)y  heating. 

Making  Plain  Bands. — As  the  plain  bands  form  such  an  important 
part  in  this  system,  it  is  important  that  proper  methods  be  employed  in 
their  making. 

Fh;.  G72. 


We  have  already  stated  our  reasons  for  preferring  nickel  silver  for 
the  making  of  regulating  appliances,  and  especially  for  the  making  of 
bands,  yet  this  metal  varies  greatly  in  quality,  not  only  on  account  of 
differences  in  the  formulae  from  which  it  is  made,  but  also  on  accoimt 
of  the  manner  of  manipulation  in  manufacture. 

It  is  important  that  it  shall  be  of  the  proper  fineness,  diameter,  and 
temper,  or  it  will  be  harsh  and  unyielding  and  difficult  or  impossible  of 
proper  adaptation  to  the  form  of  the  tooth,  in  which  case  it  will  loosen 
more  readily  under  the  strain  of  tooth  movement,  will  occupy  unneces- 
sary space  between  the  teeth,  and  present  a  less  pleasing  appearance. 

To  simply  pinch  a  short  piece  of  band  material  about  the  tooth  is  to 
make  a  loose,  crude-fitting,  and  imperfect  band  (Fig.  673).  Pieces  of 
generous  length  should  be  used,  sufficient  to  firmly  grasp  with  the 
thumb  and  fingers  after  it  has  been  slipped  around  the  tooth  to  the 
desired  point,  so  that  considerable  force  may  be  exerted  by  the  hand 
alone  in  drawing  the  loop  firmly  about  the  tooth  at  the  time  when  the 
band  is  pinched  bv  the  band-forming  pliers. 

'  The  writer  reooniniends  a  silver  solder  prepared  for  the  use  of  orthodontists  by  the 
S.  S.  AMiite  Dental  Manufacturing  Co. 


SOLDERING. 


745 


By  this  method  sufficient  pressure  is  brought  to  bear  to  make  it  fit 
with  the  greatest  accuracy  the  surface  of  the  tooth  around  which  it  is 
drawn,  and  if  the  surplus  ends  be  cut  off  so  they  will  still  be  united, 
as  in  Fig.  672,  there  will  be  very  little  waste  to  the  strips  of  band 
material,  and  ample  length  for  a  firm  grasp  will  always  be  insured.  By 
exercising  the  proper  care  a  considerable  number  of  bands  can  be  made 
from  one  of  the  coils  of  band  material  C,  F,  or  H. 

No  one  should  expect  other  than  a  very  crude  band  if  rough  or 
loose-fitting  pliers  be  used  for  pinching,  for  the  junction  of  the  pinched 

Fig.  673, 


portion  will  then  be  rounded,  as  in  Fig.  673,  instead  of  sharp  and  at 
right  angles,  as  in  Fig.  672. 

In  soldering  a  band  a  portion  of  silver  solder  about  one-eighth  of  an 
inch  square,  wet  with  borax  cream,  is  placed  between  the  angles  of  the 
band  and  held,  by  means  of  the  band-soldering  pliers,  over  the  flame. 
Fig.  674.  With  these  pliers  uniform  pressure  is  exerted  at  the  exact  points 
necessary  to  insure  the  seam  being  even  and  perfect,  while  the  minimum 
amount  of  heat  only  is  absorbed  by  the  pliers;  consequently  no  change 

Fio.  674. 


SOLDER 


of  form  or  injury  to  them  is  possible.  A  further  advantage  of  their  use 
is  that  their  points  rest  in  contact  with  the  band  material  in  such  position 
as  to  be  shielded  from  the  solder,  so  that  none  will  be  fused  upon  its 
points,  thus  avoiding  an  annoyance  of  no  small  moment  that  is  often 
encountered  in  the  use  of  ordinary  pliers,  their  contact  with  the  solder 
being  almost  a  necessity. 

To  insure  the  flowing  of  the  solder  in  the  seam  only,  plenty  of  borax 
should  be  placed  there,  but  none  on  the  inner  surface  of  the  band,  as 


746 


ORTHODONTIA. 


otherwise  tlie  solder  will  l)c  drawn  Ironi  the  .seam  and  there  will  be 
faulty  union  or  a  thiekening  ot"  the  band,  either  <>t"  which  would  render 
it  entirely  useless.  When  soldered  the  hand  should  present  a  continu- 
ous, even  inner  surface.  Any  other  union  is  imperfect  and  should  not 
be  used.  The  baud  being  ])roperly  fitted,  it  is  ready  for  any  attach- 
ments which  may  be  recjuired. 

Frc.  G7o. 


Let  us  again  insist  upon  the  importance  of  a  very  hot,  fine,  sharp- 
pointed  flame  in  the  making  of  all  these  attachments,  as  neatness  in 
such  delicate  soldering  is  impossible  with  a  coarse  flame. 

The  principal  soldered  attachments  to  the  plain  bands  are  tubes  R, 
spurs,  and  staples.  The  two  latter  are  made  from  the  wire  G,  as  shown 
in  D,  E,  G,  and  H,  Fig.  675,  and  B,  Fig.  084. 

The  attachment  of  a  spur  is  best  accomplished  by  heating  the  smoothed 
end  of  the  wire  G,  touching  it  to  a  large  piece  of  borax,  and  holding  it 

Fig.  G76. 


in  contact  with  a  small  piece  of  sohler  in  the  flame  until  it  is  partially 
fused,  then  bringing  it  in  contact  with  the  band  at  the  desired  point  and 
again  holding  it  in  the  flame.  After  it  is  fused  (Fig.  676),  it  is  clipped 
off  to  the  desired  length,  which  should  never  be  greater  than  one  thirty- 
second  of  an  inch,  and  the  roughened  ends  made  smooth  with  a  file. 
But  little  solder  should  be  used,  as  a  large  amount  would  form  an 
incline,  which  would  not  so  well  hold  the  ligature. 

If  a  staple  is  to  be  made,  the  end  of  the  wire  is  bent  into  the  form  of 


SOLDERING.  747 

the  letter  U,  the  solder  is  flowed  upon  the  surface  of  the  band  first,  then 
the  convex  portion  of  the  staple  is  held  in  contact  and  the  solder 
re-fused,  after  which  the  ends  are  clipped  to  about  one-sixteenth  of  an 
inch  in  length  and  smoothed  with  a  file,  as  in  E  and  H,  Fig.  675.  The 
jaws  of  the  staple  should  be  close  enough  together  to  prevent  much  play 
of  the  piece  it  is  to  engage. 

When  an  oval  loop,  as  in  D  and  G,  Fig.  675,  is  to  be  attached,  the 
solder  should  be  flowed  first  upon  the  band,  and  only  in  sufficient  quan- 
tity to  secure  the  loop  at  the  given  point.  A  larger  amount  is  unneces- 
sary, and  might  be  drawn  into  the  cavity  of  the  loop. 

It  is  desirable  that  all  attachments,  both  for  moving  the  tooth  and  in 
anticipation  of  retention,  shall,  if  possible,  be  made  before  first  setting 
the  band,  in  order  that  the  pain  and  trouble  of  removal  and  substitution 
of  a  new  band,  after  the  teeth  have  become  tender,  may  be  avoided. 

The  lintrimmed  ends  of  the  band  serve  the  useful  purpose  of  a  handle 
for  holding  it  in  the  flame  and  in  contact  with  the  piece  to  be  attached, 
as  in  G  and  H,  Fig.  675,  and  Fig.  676.  After  the  attachments  have 
been  made  the  ends  of  the  bands  are  trimmed  off,  leaving  them  long  or 
short,  as  desired.  If  a  niche  is  to  be  formed  to  engage  some  other  appli- 
ance, the  ends  are  left  about  one-sixteenth  of  an  inch  long;  but  if  they 
are  not  to  serv^e  as  a  means  of  attachment  they  may  be  trimmed  still 
shorter,  though  it  is  never  desirable  to  trim  them  even  with  the  surface 
of  the  band.     The  sharp  corners  should  be  rounded. 

The  canine  is  the  most  difficult  of  any  of  the  teeth  to  band,  but  by 
forming  the  seam  on  the  lingual  incline  and  firmly  burnishing  the  outer 
surface  while  it  is  being  pinched,  an  accurate  fit  can  in  most  instances 
be  made.  Another  plan  is  to  pinch  a  fold  in  the  baud  on  the  lingual 
incline,  while  it  is  being  firmly  pinched  and  drawn  with  the  fingers  on 
the  opposite  side.  The  band  is  then  removed  and  a  little  solder  flowed 
into  the  fold.  It  is  then  replaced  on  the  tooth,  and  the  seam  made  upon 
the  labial  surface  by  pinching,  burnishing,  etc.,  in  the  usual  way. 

Soft-soldering. — It  is  frequently  necessary  to  attach  sheath-hooks  to 
the  arches  E,  which  are  manufactured  in  such  a  way  as  to  give  them  the 
greatest  possible  amount  of  spring.  If  the  sheath-hooks  are  attached  by 
means  of  the  ordinary  soft  solder  with  which  they  come  provided,  the 
temper  of  the  arches  will  not  be  injured,  provided  only  a  small,  passive 
flame  be  used,  with  just  sufficient  heat  to  melt  the  low-fusing  solder. 

It  is  sometimes  desirable  to  attach  spurs  to  the  plain  arches  E  or  the 
arches  B,  to  prevent  the  slipping  of  the  wire  ligatures.  They  should 
also  be  attached  by  means  of  soft  solder,  in  order  not  to  injure  the  spring 
of  these  arches. 

The  best  plan  for  making  these  spurs  is  to  fuse  a  very  small  piece  of 
this  solder  upon  the  end  of  a  section  of  ligature  wire  (first  having  dipped 


748  ORTHODONTIA. 

the  end  of  the  wire  in  soldering  fluid),  then  holdings  it  in  contact  with 
the  arch  in  tiie  flume.  This  gives  a  fine  conical  spur  with  hrass  centre, 
which  is  very  strong,  yet  inconspicuous.  Fig.  677  shows  the  arch  with 
spurs  both  before  and  after  the  surplus  wire  has  been  cut  off.  The  spur 
should  be  no  higher  than  the  diameter  of  the  ligature  it  is  intended  to 
supj)ort,  as  if  higher  it  will  be  unsightly,  and  will  abrade  the  lips  or 
interfere  with  their  movements. 

Jewelers'  soldering  fluid  (nitro-muriate  of  zinc)  is  used  as  a  flux  in 
making  these  attachments. 

Fig.  r.77. 


Anchorage. 

Principles  of  Anchorag'e. — The  correction  of  the  position  of  a  mal- 
posed  tooth  depends  upon  two  important  things  :  first,  that  the  force 
exerted  shall  be  from  the  right  direction  and  sufficient  to  effect  the 
movement ;  and  second,  that  the  anchorage  shall  be  sufficient  to  resist 
this  force. 

In  the  application  of  force  for  the  movement  of  teeth,  the  crowns 
are  the  only  portions  available  for  effecting  the  necessary  attachments. 
Force  is  usually  exerted  at  right  angles,  or  nearly  so,  to  the  long  axes 
of  their  roots,  and  their  changes  of  positions  may  be  said  to  be  partial  or 
complete. 

In  the  fir.st  instance  the  change  is  principally  in  the  crown  end  of  the 
tooth,  it  being  tipped  into  position,  thereby  changing  its  angle  of  inclina- 
tion, with  little  or  possibly  no  apical  displacement. 


ANCHORAGE.  749 

In  the  second  case  the  tooth  is  moved  bodily,  its  coronal  and  apical 
displacement  being  more  or  less  equal,  and  in  the  same  direction. 

Whether  the  movement  shall  be  partial  or  complete  depends  upon  the 
manner  of  attachment,  which  determines  the  distribution  of  the  applied 
force.  In  the  first  instance  the  attachment  must  be  in  the  nature  of  a 
hinge  or  pivot,  so  as  to  admit  of  tipping,  as  would  follow  the  use  of  a 
ligature  made  to  exert  force  practically  at  right  angles  to  the  long  axis 
of  the  tooth. 

To  effect  the  second  form  of  movement  necessitates  that  the  attach- 
ment to  the  crown,  as  well  as  to  the  appliance  itself,  shall  be  rigid,  so 
that  tipping  will  be  impossible,  the  force  being  then  distributed  equally 
to  the  root. 

Details  of  Anchorage. — As  has  before  been  stated,  there  are  but 
seven  distinct  malpositions  that  teeth  can  occupy.  In  accordance  with 
the  laws  of  physics,  their  movement  into  harmony  with  the  line  of  occlu- 
sion can  only  be  accomplished  by  the  application  of  force  from  a  fixed 
base  of  anchorage  in  one  of  three  ways — pulling,  pushing,  or  twisting. 
As  "  for  every  action  there  is  an  equal  and  opposite  reaction,"  it  must 
follow  that  the  same  amount  of  force  will  be  exerted  upon  the  anchor- 
age as  upon  the  tooth  to  be  moved,  and  if  the  anchorage  offer  no  greater 
resistance  than  the  tooth  to  be  moved,  their  equal  displacement  must 
follow. 

For  the  moving  of  teeth  we  have  two  principal  sources  of  anchor- 
age—first, and  chiefly,  that  which  may  be  derived  from  the  teeth  them- 
selves ;  second,  that  gained  from  suitable  attachments  to  the  top  and 
back  of  the  head. 

The  resistance  offered  by  different  teeth  varies  greatly  according  to 
their  positions,  size,  length,  and  number  of  roots,  the  direction  from 
which  force  is  exerted,  and  also,  as  we  have  said,  in  the  manner  of 
mechanical  attachment. 

Of  the  many  modern  improvements  in  the  methods  of  tooth  regula- 
tion, perhaps  none  have  been  greater  than  in  the  devices  for  securing 
anchorage.  The  former  bulky  and  insecure  devices  for  this  purpose 
in  the  form  of  vulcanite  or  metal  cribs  have  become  practically  obsolete 
since  the  introduction  of  the  plain  and  clamp  bands,  which  make  possible 
much  greater  control  of  the  anchorage,  as  well  as  firmness  and  stability. 

The  force  should  be  as  direct  and  positive  as  may  be  possible  to  secure 
with  the  conditions  at  our  disposal.  The  ideal  anchorage  would,  of 
course,  be  that  from  an  immovable  base.  This,  however,  is  probably 
never  fully  possible  in  the  mouth,  owing  to  the  slight  spring  of  the 
alveolar  process  and  cushion-like  function  of  the  peridental  membrane. 
Some  displacement  of  anchor  teeth  is  admissible,  provided  they  be  kept 
within  the  limits  of  final  restoration  by  means  of  the  inclined  planes  of 


750  ORTHODONTIA. 

the  occluding  teeth  ;  hut  if  greater  displacenient  than  tins  take  place, 
nial-occlusion  of  the  anchor  teeth,  most  difficult  or  even  impossible  to 
overcome,  may  he  established.  Hence  thov  should  be  closely  \vatched 
and  careful  measurements  aud  comparisons  with  the  original  models  be 
frequently  made.  Any  unfavorable  movement  perceived  should  be 
promptly  combated.  The  embarrassment  following  any  considerable 
displacement  of  the  anclutr  teeth  is  so  serious  that  ample  anchorage 
should  always  be  secured  in  the  beginning. 

The  available  anchorage  may  be  said  to  be  of  five  kinds.  They  are 
more  or  less  intimately  associated,  and  are  used  in  combinations  or  sepa- 
rately, according  to  the  exigencies  of  requirement.  We  will  designate 
them  as?  simple,  stationary,  reciprocal,  occipital,  and  intermaxillary. 

Simple  an'chorage  is  that  form  in  which  'the  resistance  of  the 
moving  teeth  is  overcome  by  means  of  an  anchor  tooth  or  teeth  of  larger 
size  or  more  favorable  location,  the  form  of  attachment  being  hinged  or 
pivotal,  admitting  of  the  tipping  of  the  anchor  tooth  in  its  socket.  This 
form  of  anchorage,  though  often   primarily  unreliable  in  itself,  may  be 

Fig.  ()78. 


reinforced  by  enlisting  the  resistance  of  other  teeth  in  the  same  arch, 
near  or  remote  in  location. 

Stationary  anchorage  is  that  form  in  which  the  form  of  attach- 
ment is  essentially  rigid,  so  that  tipping  of  the  anchor  tooth  is  impossi- 
ble, and  if  moved  at  all  it  must  be  dragged  bodily  through  the  alveolar 
process  in  an  upright  position.  P"'ig.  678  shows  an  illustration  of  sta- 
tionary anchorage  to  a  molar  in  the  retraction  of  a  canine.  The  long 
sheath  of  the  screw  is  soldered  to  a  clamp-band  rigidly  cemented  and 
clamped  upon  the  molar,  while  the  angle  of  the  screw  engages  a  tube 
soldered  horizontally  to  a  plain  band  on  the  canine.  The  attachment  to 
the  canine  is  hinged  and  designed  for  tipping.  Should  any  displacement 
of  the  molar  occur,  both  root  and  crown  would  be  moved  equally  and  in 
the  same  direction.  It  will  thus  be  seen  that  the  resistance  in  this  form 
of  anchorage  is  vastly  greater  than  in  the  simple  form. 

Skill  and  judgment  are  necessary  in  the  use  of  this  form  of  anchor- 
age, for  its  success  depends,  first,  on  the  absolute  rigidity  of  the  attach- 
ment and  appliance,  and  second,  on  the  amount  of  force  exerted,  which 


ANCHORAGE. 


751 


must  not  at  any  time  be  so  great  as  to  strain  or  injure  it.  This  is  of 
vital  importance,  for  any  loosening  or  straining  of  the  anchorage  would 
immediately  change  it  to  ordinary  simple  anchorage. 

Reciprocal  axchoeage  is  that  form  in  which  one  malposed  tooth 
is  pitted  against  another  in  the  same  arch,  the  tendency  of  the  force, 
correctly  applied,  being  to  move  both  into  the  line  of  occlusion. 

Reciprocal  anchorage  admits  of  the  widest  range  of  application  and 

Fig.  679. 


is  the  most  valuable  form  of  anchorage.  Each  case  should  be  studied 
carefully  with  a  view  to  its  use  whenever  possible,  either  in  its  simplest 
forms,  as  in  Fig.  679,  or  when  a  greater  number  of  teeth  are  to  be 
moved,  as  in  widening  the  arch  (Fig.  687),  or  in  combination  with 
other  forms  of  anchorage.  It  will  be  found  applicable  to  a  very  large 
percentage  of  cases,  and  is  an  important  principle  in  many  of  the  com- 
binations of  appliances  hereafter  shown. 


Fig.  680. 


Fig.  681. 


Occipital  ajn^chorage  is  that  form  in  which  the  resistance  is  borne 
by  the  top  and  back  of  the  head  and  transmitted  by  means  of  the  head- 
gear and  heavy  elastics  to  attachments  upon  the  teeth,  as  in  Fig.  655. 
This  well-known  form  of  anchorage,  heretofore  principally  applicable 
in  the  treatment  of  cases  belonging  to  Division  1  and  its  subdivision 
of  Class  II.  and  to  Class  III.,  has,  in  the  writer's  practice,  been  practi- 
cally superseded  by  the  Baker  anchorage,  described  below. 


nyi 


ORTHODONTIA. 


Intermaxfi.lauy  an(II(>1{A(;k  is  so  designated  because  the  prin- 
ciple involved  is  such  as  to  require  distinction  from  other  anchor- 
ages. It  is  a  new  form  of  anchorage,  ditl'cring  from  those  already 
described  in  that  the  anchorage  or  resistance  to  the  moving  teeth  is 


Fiu.  68± 


derived  from  the  teeth  of  the  opposite  arch.     This  may  or  may  not  be 
used  reciprocally. 

Figs.  680  and  681  illustrate  this  form  of  anchorage  in  cases  where 
it  is  not  used  reciprocally,  the  elevation  of  the  upper  canines  being 
accomplished  by  means  of  rubber  ligatures  attached  to  devices  on  the 


Fig.  683. 


lower  teeth,  and  the  lower  teeth  prevented  from  elevating  by  tFTe  irre- 
sistible pressure  of  occlusion.* 

Fig.  763  shows  a  remarkable  case  where  this  anchorage  was  made 
to  act  reciprocally  in  forcing  the  elevation  of  both  upper  and  lower 
incisors,  canines,  and  premolars.     This  form  of  anchorage  is  direct  and 


'  This  form  of  anchorage  was  introduced  by  the  writer.     See  Denied  Cosmos,  1891,  p. 


743. 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  753 

powerful,  and  may  often  be  employed  to  much  advantage.  Its  impor- 
tance in  the  modification  now  known  as  the  "  Baker  anchorage  "  ^  is  so 
great  as  to  mark  an  epoch  in  the  evolution  of  orthodontia,  for  with  it 
the  entire  plan  of  treatment  of  cases  belonging  to  both  Classes  II.  and 
III.  has  been  revolutionized,  and  instead  of  those  cases  being  the  most 
difficult  as  well  as  unsatisfactory  to  treat,  they  have  become,  by  the 
intelligent  application  of  this  form  of  anchorage,  among  the  easiest  and 
most  satisfactory  cases  that  we  are  called  upon  to  treat ;  that  is,  if  taken 
at  the  proper  age  and  intelligently  managed.  This  form  of  anchorage, 
as  used  by  Dr.  Baker,  is  shown  in  Fig.  682,  and  the  writer's  modifica- 
tion is  shown  in  Fig.  683. 

Adjustment  and  Operation  of  Appliances. 

The  hundreds  of  appliances  that  have  been  used  in  dilFerent  hands 
in  the  various  periods  of  dental  history  might  be  classified  into  a  very 
few  groups,  each  group  representing  merely  variations  of  a  single 
mechanical  principle.  Therefore  the  very  common  practice  of  advocat- 
ing indiscriminately  nearly  every  appliance  that  has  ever  been  made  to 
serve  a  purpose  is,  we  believe,  not  only  unnecessary,  but  misleading  and 
fruitful  of  much  harm. 

Thorough  familiarity  with  and  experience  in  the  use  of  a  few  appli- 
ances of  desirable  form  will  reveal  possibilities  of  accomplishment 
which  would  never  follow  in  the  case  of  a  large  variety  each  of  which 
might  be  only  occasionally  used. 

Those  appliances  which  the  writer  has  found  from  much  experience 
to  be  the  most  useful  will  be  chiefly  specified  in  the  descriptions  of 
treatment  in  the  following  pages  ;  but  that  there  may  be  ample  range 
of  choice,  a  number  of  others  will  also  be  mentioned  as  being  possibly 
desirable  in  certain  cases. 

An  ideal  appliance  is  one  that,  properly  operated,  will  perform  all 
necessary  movements,  whether  lingual,  labial,  mesial,  distal,  of  depres- 
sion, elevation,  or  rotation,  or  their  combinations,  not  only  with  indi- 
vidual teeth  nor  of  the  teeth  of  one  arch  alone,  but  all  movements 
required  of  all  teeth  in  both  arches,  carrying  all  on  simultaneously — 
one  applicable  to  any  case  of  any  class,  from  the  simplest  to  the  most 
complicated   in   which  treatment  is  practicable,  and  one  that  shall  be 

^  To  the  best  of  my  knowledge  and  belief  we  are  indebted  to  Dr.  H.  A.  Baker,  of 
Boston,  for  this  idea,  he  having  used  it  in  the  retraction  of  the  protruding  incisors  of  his 
son  a  number  of  years  ago,  and  it  was  from  him  I  received  the  idea.  I  have  hence  called 
it  the  "  Baker  anchorage."  Dr.  Calvin  S.  Case,  of  Chicago,  also  employed  this  form  of 
anchorage,  probably  at  about  the  same  time  as  Dr.  Baker,  not,  however,  as  anchorage  com- 
plete by  itself,  as  did  Dr.  Baker,  but  only  as  auxiliary  to  occipital  anchorage  in  a  case 
belonging  to  the  third  class.  It  is  reported  in  the  Transactions  of  the  Columbian  Dental 
Congress. 

48 


754 


ORTHODONTIA. 


under  the  perfect  control  of  the  operator,  who  may  hasten  the  move- 
ment of  some  teeth  and  retard  that  of  others,  as  occasion  may  require, 
yet  a  device  so  simple  as  to  be  easily  comprehended,  and  occasion  the 
minimum  amount  of  inconvenience  to  the  patient.  The  writer  believes 
we  at  last  have  practically  all  of  the  requirements  we  have  enumerated. 


Fi(i.  ()84. 


in  the  appliance  known  as  the  expansion  arch,  and  shown,  with  its  aux- 
iliaries, in  Figs.  684  and  685. 

This  appliance  is  made  up  of  one  of  the  arches  E,  plain  or  ribbed, 
or  the  arch  B,  anchored  to  the  teeth  by  means  of  the  anchor  clamp- 
bands  D  or  X,  and  used  with  the  auxiliaries  of  plain  or  spurred  bands, 
wire  ligatures,  rubber  wedges,  and  rubber   ligatures,  according  to  the 

Fi(i.  685. 


EJIA 


requirements  of  the  case.  This  appliance,  in  slightly  varying  combina- 
tions, is  practically  the  only  one  now  used  by  the  writer.  Its  great 
value  and  almost  limitless  range  of  possibilities  will  become  more  and 
more  appreciated  in  proportion  as  it  is  studied  and  used. 

Adjustment  of  Clamp-bands. — In  adjusting  this  appliance  the  first 
step  is  the  fitting  of  the  anchor  clamp-bands,  either  D  or  X.     The  use 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  755 

of  the  D  bands  on  the  first  molars  is  usually  preferable,  as  these  are  the 
largest  and  firmest  of  the  teeth,  thereby  affording  the  firmest  anchorage. 
Occasions  may  arise,  however,  in  which  it  may  be  desirable  to  adjust 
these  bands  to  the  second  or  third  molars.  The  X  bands  on  the  pre- 
molars, used  either  on  one  or  both  sides,  may  also  sometimes  be  desir- 
able, but  their  use  is  only  occasionally  demanded. 

In  adjusting  a  clamp-baud,  the  nut  should  first  be  loosened  suffi- 
ciently to  allow  aynple  size  for  the  crown  over  which  it  is  to  slip.  The 
band  should  then  be  shaped  between  the  flat  beaks  of  the  band-forming 
pliers  until  it  conforms  approximately  to  the  shape  of  the  crown  of  the 
tooth,  the  shaft  of  the  screw,  which  should  always  point  forward  unless 
for  some  special  reason,  being  bent  also  if  necessary.  The  band  should 
then  be  worked  carefully  over  the  crown  with  the  fingers  and  made  to 
slide  between  gum  and  enamel  to  the  desired  point,  and  then  alternately 
clamped  and  burnished  until  made  to  conform  accurately  to  the  shape 
of  the  crown. 

Fig.  686. 


One  of  the  greatest  blunders  made  in  adjusting  these  bands  is  to 
trim  or  file  the  band  on  its  edge  in  order  to  prevent  supposed  interfer- 
ence with  the  gums.  Such  procedure  only  ruins  the  band.  Besides,  it 
is  essential  that  this  portion  of  the  band  shall  pass  beyond  the  swell 
of  the  crown  and  be  clamped  and  burnished  to  the  neck  of  the  tooth 
to  prevent  its  slipping  off.     Thi's  is  the  most  valuable  part  of  the  band. 

Another  blunder  frequently  made  is  to  begin  the  clamping  or  bur- 
nishing before  the  band  is  well  over  the  crown.  In  this  case  part  of 
the  band  must  bear  the  entire  strain,  and  will  be  stretched  or  torn,  or 
the  band  will  loosen  and  come  off. 

It  is  a  mistake  to  allow  the  screw  to  stand  out  at  too  great  an  angle. 
The  band  should  be  turned  before  clamping  until  the  screw  is  in  close 
contact  with  the  adjoining  teeth.  It  is  then  not  only  out  of  the  w^ay 
and  will  give  no  annoyance  to  the  tongue  or  lips,  but  the  projecting  end 
may  be  of  great  value  for  the  attachment  of  auxiliary  devices  on  occa- 
sion. 

The  bands  are  made  to  endure  the  greatest  possible  strain  consistent 
with  their  nearly  ideal  proportions.     They  will,  therefore,  bear  consid- 


756  ORTHODONTIA. 

erablc  tightening;  of  the  nut,  yet  if"  tliis  he  carried  too  far  thev  may  be 
l)n)ken.  It  is  u.sually  best  not  to  clamp  tlie  band  too  tightly  at  first, 
but  to  wait  until  the  second  or  third  sitting  for  the  final  clamping  and 
burnishing.  The  clamping  of  the  bands  is  ample  to  so  secure  them  in 
position  that  cement  is  unnecessary  except  in  effecting  stationary  anchor- 
age, as  in  the  use  of  the  traction-screw,  shown  in  Fig.  fi78. 

Fig.  686  shows  a  i)  band  which  has  been  properly  adjusted  to  the 
crown  of  a  molar.  It  will  be  noted  that  it  accurately  conforms  to  the 
swell  of  the  crown.  A  small  portion  of  the  upper  edge  has  been  bur- 
nished over  the  distal  marginal  ridge.  This  is  important  to  prevent  the 
possibility  of  the  working  of  the  band  too  far  over  the  crown.  A  band 
so  adjusted  offers  the  firmest  anchorage,  and  cannot  be  loosened  without 
breaking  or  unturning  the  nut. 

If  the  teeth  to  be  banded  are  crowded,  care  and  patience  are  neces- 
sary to  work  the  band  into  position.  This  is  usually  easy  with  young 
patients,  as  their  teeth  admit  of  considerable  movement.  The  band  is 
worked  between  the  teeth  on  one  side  first,  and  allowed  to  remain  for  a 
few  minutes,  then  the  other  side  is  gently  rocked  and  pressed  with  the 
finger,  or,  better,  with  a  flat  piece  of  Avood,  until  started  to  place  between 
the  teeth.  It  is  then  well  to  allow  it  to  rest  for  a  few  minutes,  begin- 
ning the  same  operation  with  the  band  for  the  tooth  on  the  opposite  side 
of  the  mouth,  after  which  sufficient  separation  will  usually  have  taken 
place  to  readily  permit  of  the  further  adjustment  of  the  first  band. 

Sometimes  after  adjustment  of  the  anchor-band  it  is  found  that  the 
mesially  adjoining  tooth  inclines  buccally  to  such  a  degree  as  to  prevent 
the  passing  of  the  end  of  the  arch  into  the  sheath.  This  is  readily 
remedied  by  unsoldering  the  sheath  from  the  band  and  resoldcring  it, 
with  a  piece  of  metal  of  sufficient  thickness  intervening.  Usually  a 
portion  of  a  ten-cent  piece  is  ample.  By  this  means  the  sheath  is  pro- 
jected buccally  sufficiently  for  the  ready  insertion  of  the  end  of  the 
arch. 

Occasionally  a  case  maybe  found  where  the  tooth  which  it  is  desired 
to  u.se  as  anchorage  inclines  forward  at  such  an  angle  that  the  sheath  on 
the  D  baud  will  not  properly  line  with  the  expansion  arch  (see  Figs. 
771  and  772).  In  this  case  the  band  should  be  removed  and  the  sheath 
detached  and  resoldered  at  the  proper  angle.  This  may  be  readily  effected 
by  placing  a  small  piece  of  solder  and  borax  at  the  union  of  the  band  and 
sheath,  applying  heat,  and  turning  the  band  as  desired.  It  is,  however, 
rarely  necessary,  as  by  slightly  bending  the  arch  and  shifting  the  band 
it  can  in  most  instances  be  properly  adjusted  without  changing  the  posi- 
tion of  the  tube. 

AVhathas  been  said  regarding  the  adjustment  of  the  D  bands  will,  of 
course,  apply  to  the  adjustment  of  the  X  and  plain  adjustable  bands  also. 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  757 

Adjustment  of  Plain  Bands. — In  adjusting  the  plain  bands  the 
tooth  to  be  banded  is  first  cleansed,  then  dried  and  protected  from 
moisture.  The  band  is  filled  with  oxyphosphate  of  zinc  of  creamy  con- 
sistence, then  carried  on  the  end  of  the  finger  to  the  tooth,  upon  which 
cement  and  band  are  pressed.  With  the  fingers  alone  the  band  is  care- 
fully worked  nearly  to  its  desired  position,  and  then  driven  down  by  a 
few  gentle  taps  from  the  mallet  and  band-driver.  The  burnisher  is  now 
quickly  applied  to  the  edges  of  the  band  only,  and  the  surplus  cement 
wiped  off.  When  the  cement  has  thoroughly  hardened  the  band  should 
be  polished  and  burnished,  as  it  is  well  known  that  discoloration  is  far 
less  liable  with  a  smooth,  polished  surface  than  with  a  rough  one. 

A  band  made  as  described  in  the  section  on  Soldering,  and  set  as 
above,  will  fit  with  the  most  glove-like  accuracy,  will  present  a  very 
neat  appearance,  and  will  not  loosen  under  necessary  strain.  If  it  is 
defective  in  any  particular,  as  too  large,  weakened  by  crimping,  or 
slightly  torn  when  driven  into  position,  it  should  be  immediately  con- 
demned and  a  perfect  one  substituted,  for  sooner  or  later  it  will  surely 
fail  and  cause  annoyance. 

In  banding  a  tooth  where  there  is  much  crowding  it  may  be  necessary 
to  provide  space  in  advance.  Usually,  however,  by  exercising  a  little 
care  and  patience,  the  banding  may  be  done  at  one  sitting. 

Adjustment  of  Expansion  Arches. — In  adjusting  any  of  the  ex- 
pansion arches,  they  are  first  made  to  conform  approximately  to  the  shape 
of  the  ideal  dental  arch,  or  as  we  wish  the  teeth  to  be  arranged  when 
the  movements  are  completed.  It  therefore  become.s  a  guide  and  pattern 
for  the  proper  alignment  of  the  teeth,  as  well  as  the  means  of  effecting 
their  movement  by  reason  of  its  elasticity,  in  connection  with  the  wire 
ligatures.  The  adjustment  of  the  size  of  the  expansion  arches  for  the 
requirements  of  the  teeth  to  be  moved  into  proper  alignment  is  con- 
trolled by  the  nuts  in  front  of  the  anchor  tubes.  The  tendency  of 
beginners  is  to  depend  principally  on  the  tightening  of  the  nuts  for 
applying  pressure  on  the  moving  teeth.  This,  however,  is  a  mistake,  as 
the  principal  force  should  be  derived  from  the  ligatures  and  the  elasticity 
of  the  arch. 

Adjustment  of  "Wire  Ligatures. — Unquestionably  the  greatest 
modern  improvement  in  connection  with  the  use  of  the  arch  is  the  sub- 
stitution of  ligatures  of  brass  ^  for  other  forms  of  ligatures,  on  account 
of  their  greater  strength,  cleanliness,  and  freedom  from  stretching  or 
slipping,  making  their  force  direct  and  positive.  With  them  the  possi- 
bilities in  the  use  of  the  arch  are  greatly  extended,  shortening  the  time 
of  treatment,  and  making  easy  much  that  was  impracticable  or  even 

^  Fourth  edition  of  the  Angle  System,  of  Regulation  and  Retention  of  the  Teeth  and 
Fractures  of  the  Maxillce. 


758 


ORTHODONTIA. 


impossible  before.  Their  most  valuable  (luality  is  that  they  may  be 
tigiitened  by  twisting,  without  renewal,  possessing  thereby,  iii  addition 
to  their  primary  usefulness,  tlu'  ideal  j)()wer  of  the  serew,  and  obviating 
the  neeessity  for  the  oft  relincpiishment  and  reapplieation  of  pressure  on 
the  moving  tooth,  as  must  follow  the  use  of  other  ligatures — the  prin- 
eipal  source  of  pain  and  inflammation  in  regulating.  It  is  verv  impor- 
tant, however,  that  only  wire  of  the  proper  metal,  quality,  and  size  be 
used.  It  is  also  important  that  in  temper  it  shall  be  very  soft,  so  made 
during  its  manufacture.     Wire  of  spring  temper  is  entirely  useless. 

^^'hen  applying  a  wire  ligature  a  piece  long  enough  to  be  firmly 
grasped  by  both  hands  should  be  used,  so  that  strong  tension  may  be 
exerted  when  making  the  twist.  This  should  never  be  more  than  three- 
fourths  of  a  turn  at  first.  The  surplus  ends  are  then  clipped  off,  leaving 
projections  one-eighth  of  an  inch  long.  These  ends  are  then  curled 
under  the  arch,  as  correctly  shown  in  Figs.  684  and  687,  thus  providing 

Fig.  687. 


a  smooth  surface  to  the  lips.  Never  attempt  to  i^end  the  twisted  portion 
of  the  ligature  out  of  the  way,  as  by  so  doing  the  entire  strain  is  brought 
on  one  strand,  and  the  ligature,  in  almost  every  instance,  broken. 

In  tightening  the  ligature,  firmly  press  the  tooth  and  arch  between 
the  thumb  and  finger  while  giving  it  another  half-turn  with  suitable 
pliers.  It  should  be  remembered  that  the  spring  of  the  expansion  arch, 
when  used  in  connection  with  the  wire  ligature,  is  constantly  acting,  so 
that,  as  a  rule,  tightening  of  a  ligature  need  be  done  only  occasionally. 

Although  the  uses  of  the  wire  ligature  in  orthodontia  are  limitless, 
there  are  three  principal  ways  of  applying  it  in  ligature  form  :  first,  the 
simple  ligature,  as  in  A  A.  Fig.  684,  where  it  is  made  to  engage  a  single 
tooth  and  the  expansion  arch,  where  direct  labial  or  buccal  movement  is 
required  ;  second,  where  rotation  and  possibly  labial  movement  is  re- 
quired the  ligature  is  made  to  engage  the  expansion  arch  and  a  spur 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  759 

upon  a  band  cemented  to  the  tooth,  as  in  B,  Fig.  684 ;  third,  the  double- 
loop  ligature,  as  in  C,  Fig.  684,  to  effect  the  same  movement.  The 
ligature  applied  in  this  manner  is  more  uncertain  in  its  results  than 
when  applied  as  last  shown,  and  should  only  occasionally  be  used.  Its 
greatest  use  will  be  found  in  the  temporary  retention  of  an  incisor  to 
the  arch  after  rotation,  while  the  movements  of  other  teeth  are  being 
completed. 

Combination  Adjusted. — Fig.  687  shows  this  combination  of  appli- 
ances adjusted  to  the  teeth  of  the  upper  arch  in  the  very  complicated 
case  shown  in  Fig.  732,  requiring  the  movement  of  all  the  teeth  in 
both  arches  and  oifering  the  severest  test  to  a  regulating  appliance,  and 
at  the  same  time  offering  us  the  best  of  opportunities  for  its  study  with 
a  view  to  its  proper  adjustment  and  operation,  not  only  in  this  case,  but 
for  all  general  uses.  Its  more  extended  uses  in  special  cases  will  be 
noted  later  in  the  treatment  of  individual  cases.  In  this  case  the  upper 
dental  arch  requires  much  widening,  while  both  centrals  and  both  later- 
als are  to  be  carried  forward  and  outward  and  rotated,  and  the  canines 
are  to  be  elevated  in  their  sockets. 

Plain  spurred  bands  and  ligatures  are  adjusted  to  all  the  incisors  for 
their  combined  labial  movement  and  rotation,  the  spurs  on  the  plain 
bands  having  been  so  placed  that  pressure  exerted  by  reason  of  the  elas- 
ticity of  the  arch  through  the  wire  ligatures  will  bear  most  heavily  on 
the  angles  of  these  teeth  that  are  turned  lingually,  and  as  they  are  rotated 
they  will  also  be  drawn  labially.  By  using  the  ribbed  expansion  arch 
and  notching  the  rib  for  the  more  stable  attachment  of  the  ligatures,  the 
direction  of  force  for  moving  these  teeth  is  absolutely  controlled. 

The  first  molars,  attached  to  the  expansion  arch  through  the  clamp- 
bands,  are  moved  buccally  by  reason  of  the  lateral  spring  of  the  expansion 
arch.  The  first  premolars  are  moved  in  the  same  direction  through  their 
attachment  to  the  arch  by  plain  wire  ligatures,  and  the  second  premolars 
through  contact  with  the  screw  of  the  D  band.  Pressure  on  the  canines 
to  move  them  lingually  may  be  intensified  by  rubber  wedges  stretched 
between  teeth  and  arch  and  the  superfluous  ends  cut  off,  as  shown  in 
Fig.  685. 

By  carefully  studying  this  picture  it  will  be  seen  how  perfectly  force 
is  distributed  to  accomplish  the  various  necessary  tooth  movements,  and 
how,  as  in  all  fine  mechanisms,  each  part  assists  and  is  in  harmony  with 
each  other  part.  For  example,  note  how  perfectly  the  force  is  recipro- 
cated from  one  moving  tooth  to  another ;  from  one  lateral  half  of  the 
dental  arch  to  the  other,  and  how  this  is  intensified  by  the  pressure  on 
the  centre  of  the  expansion  arch  in  front,  the  tendency  being  when  press- 
ure is  exerted  at  this  point,  as  in  all  arches,  to  spring  the  ends  farther 
apart.     As  the  central  incisors  are  being  rotated,  much  force  is  exerted 


700 


ORTHODONTIA. 


upon  tlu'iii  at  tlu'ir  (liM<;^<»nall\"  oppositi'  coniers;  in  reality  the  arch 
operating  on  oacli  as  two  lovers  conihinetl,  the  power  ends  acting  in  (lifer- 
ent directions.  No  tooth  can  resist  this  torce.  At  the  same  time  all 
four  incisors  are  being  carried  forward  by  the  irresistible  force  of  what 
is  practically  two  jack-screws  combined. 

In  the  anterior  teeth,  one  lateral  incisor  reciprocates  its  force  to  the 
other,  one  central  to  the  other,  all  in  ])erfect  harmony.  Note,  also,  what 
complete  control  we  have  over  the  teeth  singly  and  collectively,  yet  at 
the  same  time  the  anchorage  is  practically  derived  from  all  of  the  teeth 
in  the  arch. 

With  this  appliance  we  may  not  only  expand  the  arch  in  all  directions, 
as  recjuired  in  this  case  and  here  shown,  but,  as  we  shall  see  in  the  sec- 
tion on  Treatment,  we  may  widen  or  narrow  either  or  both  of  the  dental 
arches  on  one  or  both  sides,  or  we  may  lengthen  or  shorten  one  or  both 

Fig.  688. 


of  the  lateral  halves.  We  may  move  a  single  tooth  in  any  direction, 
or  we  may  lengthen  the  teeth,  and,  to  a  limited  extent,  effect  their 
shortening. 

In  the  adjusting  of  the  arch,  as  here  shown,  it  will  be  seen  that  it  is 
placed  high  up  toward  the  gum,  as  it  should  be  in  all  cases.  This  is 
necessary  in  order  to  keep  that  intense,  rigid  tension  upon  the  moving 
teeth,  for  if  the  arch  be  allowed  to  slip  down  (its  natural  tendency) 
toward  the  points  of  the  teeth,  it  will  lose  much  or  all  of  its  force,  and 
become  a  wobbly,  inefficient  encumbrance. 

The  tendency  of  amateurs  is  often  to  bend  the  arch  so  that  it  will 
be  too  narrow  in  the  anterior  part  and  bind  on  the  canines,  preventing 
the  proper  adjustment  of  the  incisors.  It  should  be  bent  so  as  to  afford 
ample  room. 

Another  common  failing  of  the  inexperienced  is  to  give  the  arch  so 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  761 

much  lateral  spring  as  to  cause  buccal  displacement  of  the  anchor  teeth 
in  cases  where  no  buccal  movement  of  these  teeth  is  necessary. 

By  the  addition  to  this  combination  of  sheath-hooks  and  rubber  liga- 
tures used  in  the  Baker  anchorage,  all  of  the  upper  teeth  may  be  moved 
distally  and  all  the  lower  teeth  mesially,  as  illustrated  in  Fig.  683,  or 
these  movements  may  be  reversed,  as  shown  in  Fig.  688,  and  all  this  in 
connection  with  any  other  tooth  movements  that  may  be  required  in 
either  or  both  arches. 

The  modifications  of  form  and  directions  of  spring,  plus  the  modifi- 
cations in  ligature  attachments,  make  it  possible  to  derive  wonderful 
combinations  and  results,  and  in  its  use  it  is  possible  to  cultivate  a  very 
high  degree  of  skill.  It  typifies  efficiency  and  simplicity.  It  is  easily 
applied,  and  is  so  stable  in  its  attachment  that  there  need  be  no  slipping  or 
loss  of  power.  It  is  cleanly,  and  occupies  a  position  in  the  mouth  that 
causes  the  least  inconvenience  to  the  patient.  If  this  device  be  intelli- 
gently managed,  it  need  interfere  but  little  with  the  normal  functions  of 
the  mouth.  On  the  contrary,  however,  if  improperly  managed  it  becomes 
a  constant  annoyance,  as  has  been  said,  and  one  of  the  most  wobbly  and 
useless  of  devices. 

In  its  proper  use  the  widest  range  for  reciprocal  anchorage  is  possible. 
We  may  also  gain  simple  and  a  considerable  degree  of  stationary  anchor- 
age by  reason  of  the  tubes  and  firm  attachment  of  the  anchor-bands  to 
the  teeth  used  as  anchorage,  and  also,  as  we  have  seen,  the  very  valuable 
intermaxillary  anchorage. 

The  necessary  direction  and  distribution  of  force  should  be  carefully 
studied  in  each  case,  as  well  as  the  effect  upon  the  anchor  teeth  and  all 
that  are  in  proper  position. 

The  arch  should  always  be  made  to  lie  approximately  close  to  the 
teeth,  so  as  to  interfere  as  little  as  possible  with  the  functions  of  the  lips. 

It  should  be  remembered  that  as  its  force  in  tooth  movement  is 
exerted  usually  by  its  elasticity,  its  careful  bending  in  order  to  secure  the 
proper  degree  and  direction  of  force  is  of  much  importance.  To  make 
the  most  of  this  possibility,  and  at  the  same  time  avoid  interference  with 
desired  movements  or  with  teeth  already  in  correct  position  by  binding, 
is  the  most  difficult  problem  in  its  management,  and  yet  it  is  easily  solved 
if  intelligently  studied  in  each  case. 

As  a  result  of  years  of  experimenting,  it  is  believed  that  as  here 
shown,  with  its  improvements  and  attachments  (Fig.  642),  it  is  very 
nearly  perfect. 

In  order  that  the  patient  may  become  gradually  accustomed  to  the 
appliances,  the  bands  should  be  worn  for  two  or  three  days,  then  the  arch 
added  without  ligatures  for  three  or  four  days  more,  and  finally,  all  care- 
fully and  thoroughly  adjusted  and  the  ligatures  applied  for  the  movement 


70l'  orthodontia. 

t)f  tlu'  tt't'tli.  Tliov  slioukl  be  very  liirlit  of  tension  at  first,  the  object 
boinij,  ot"c'(>urse,  to  begin  so  gently  that  the  patient  may  become  accus- 
tomed to  the  wearing  of  the  device  witii  no  pain  and  with  but  the  mini- 
mnm  amount  of  inoonvenicneo,  all  of  which  is  easily  possible.  The  ten- 
dency of  all  appliances  upon  the  teeth  is  at  first  to  excite  more  or  less 
inHammation,  which  will  be  in  proportion  to  the  amount  of  force  exerted; 
therefore  we  cannot  too  strongly  recommend  that  tiie  adjustment  of  the 
appliances  always  be  gradual,  and  the  force  exerted  in  the  beginning 
most  gentle.  Later,  nuieh  pressure  can  be  borne  with  little  inconve- 
nience. 

AVhat  we  have  already  said  in  regard  to  the  fitting  and  adjusting  of 
the  anchor-bands,  the  shaping,  fitting,  and  adjusting  of  the  expansion 
arch  and  its  attachment  to  the  teeth  to  be  moved  by  means  of  plain  or 
loop  ligatures,  or  spurred  bands  and  ligatures,  is  equally  applicable  to  its 
use  upon  the  teeth  of  the  lower  arch  when  their  movement  is  necessary 
in  order  to  establish  harmony  of  occlusion.  And  although  in  cases  met 
with  for  treatment  the  mal-occlusion  always  differs,  the  adjustment  of 
the  expansion  arch  as  here  given  is  practically  always  the  same,  the  prin- 
cipal difference  being  in  the  form  given  the  arch  by  bending  in  order  to 
exert  force  in  the  desired  direction,  and  in  the  direction  of  the  ligatures 
and  their  attachments  to  the  teeth  to  be  moved. 

Combinations  for  Baker  Anchorage. — Fig.  683  shows  a  very  impor- 
tant combination  of  the  expansion  arches  in  which  the  Baker  anchorage 
is  used  in  the  movement  distally  of  the  teeth  of  the  upper  and  mesially 
those  of  the  lower  arch  in  the  correction  of  the  occlusion  of  cases  belong- 
ing to  Class  II. 

The  arches  are  adjusted  in  the  usual  way,  and  sheath-hooks  are 
attached  to  the  upper  arch  at  points  opposite  the  lateral  incisors.  Either 
the  plain  or  ribbed  arches  may  be  used,  but  the  plain  arch  is  preferable 
in  this  combination  unless  other  movements  of  the  incisors  and  canines 
are  necessary,  as  already  described,  and  illustrated  in  Fig.  687.  The 
force  is  exerted  by  means  of  one  or  more  small  rubber  ligatures,  which 
engage  the  sheath-hooks  on  the  upper  expansion  arch  and  the  distal  ends 
of  the  sheaths  of  the  anchor-bands  on  the  lower  molars. 

The  nuts  anterior  to  the  sheaths  of  the  bands  on  the  upper  first  molars 
are  occasionally  tightened,  as  the  molars  are  moved  distally,  so  as  to 
exert  all  of  the  force  upon  them,  instead  of  expending  any  of  it  upon  the 
prominent  incisors,  for  the  time  being. 

After  the  upper  molars  have  been  moved  distally  into  full  normal 
occlusion,  it  will  be  found  that  a  space  exists  between  the  molars  and 
second  premolars.  The  D  bands  on  the  upper  first  molars  are  then 
removed,  and  X  bands  are  placed  on  the  second  premolars.  The  nuts  on 
the  expansion  arch  are  moved  forward  and  the  arch  again  adjusted,  and 


ADJUSTMENT  AND   OPERATION  OF  APPLIANCES.  763 

tlie  force  from  the  rubber  ligatures  again  exerted  in  order  to  carry  dis- 
tally  the  upper  premolars.  A  wire  ligature  is  made  to  engage  the  upper 
first  and  second  premolars  in  order  to  effect  their  movement  at  the  same 
time.  As  previously,  in  moving  the  molars,  the  nuts  are  kept  tight 
against  the  sheaths  of  the  X  bands  in  order  to  exert  all  the  force  on  the 
premolars  and  none  on  the  incisors.  When  these  teeth  are  well  back 
into  correct  mesio-distal  relations  with  the  lower,  the  nuts  are  gradually 
loosened  to  allow  force  to  be  received  by  the  incisors  and  canines,  which, 
in  turn,  are  soon  moved  into  correct  relation  with  their  antagonists. 

If  care  and  judgment  be  exercised,  the  operator  will  often  be  sur- 
prised by  the  ease  and  rapidity  with  which  the  teeth  are  adjusted  in  these 
pronounced  deformities. 

It  is  well  known  to  those  having  had  experience  that  teeth  move 
raesially  more  readily  than  distally.  This  being  the  case,  the  tendency 
is  for  the  lower  teeth  to  move  more  rapidly  than  the  upper.  This  is 
easily  controlled  by  lacing  the  lower  incisors  to  the  lower  expansion  arch 
with  wire  ligatures,  having  first  given  the  arch  a  downward  bend,  so  that 
when  it  is  lifted  up  by  the  ligatures  it  is  made  to  bind  in  the  sheaths  of 
the  bands  on  the  first  molars,  or  exerting  the  same  strain  upon  the  apex 
of  their  roots  as  upon  their  crowns,  thus  enormously  increasing  their 
resistance.  By  taking  advantage  of  this  possibility  (stationary  anchor- 
age) complete  control  is  easily  gained  in  the  amount  that  the  teeth  of 
each  arch  may  be  moved.  These  ligatures  may  also  be  used  to  effect 
any  necessary  adjustment  of  the  lower  incisors. 

Plain  bands  are  not  indicated  on  any  of  the  incisors  unless  their  rota- 
tion is  necessary,  the  wire  ligatures  alone  being  sufficient. 

As  the  upper  molars  move  distally,  the  tendency  of  the  anterior  part 
of  the  upper  expansion  arch  is  to  move  downward  toward  the  cutting 
edges  of  the  incisors.  It  is,  therefore,  necessary  to  occasionally  loosen 
the  bands  on  the  upper  molars  (or  premolars)  and  adjust  them  to  proper 
alignment  of  the  sheaths,  so  that  the  anterior  part  of  the  arch  will  be 
kept  well  up  toward  the  gum. 

The  operation  of  this  combination  of  appliances  in  the  treatment  of 
cases  belonging  to  the  subdivisions  of  this  class  is  identical  with  that 
just  described,  except  that  it  is  limited  to  the  side  of  the  arches  in 
distal  occlusion.  Only  one  sheath-hook  should  be  used,  with  its  accom- 
panying rubber  ligatures. 

In  the  treatment  of  cases  belonging  to  Class  III.  the  same  combina- 
tion of  appliances  is  used,  but  the  plan  of  operation  is  reversed,  as 
shown  in  the  diagram  (Fig.  688).  The  sheath-hooks  are  attached  to 
the  lower  expansion  arch,  well  forward,  and  rubber  ligatures  stretched 
between  them  and  the  distal  ends  of  the  sheaths  of  the  anchor-bands  on 
the  upper  molars. 


'64 


ORTHODONTIA. 


For  the  tr(>atniont  of  cases  belonging  to  the  subdivision  of  Class  III. 
the  same  combination  of  aj)pliances  is  used,  with  force  from  the  rubber 
ligatures  exerted  on  the  aI)normal  side  only. 

It  will  be  seen  that  all  cases  of  all  classes  may  be  treated  with  this 
appliance,  and,  we  now  believe,  more  ([uickly,  more  easily,  far  better, 
and  with  far  less  inconvenience  to  the  jiatient  than  with  any  other  form 
of  ap])liance.  It  is  the  one  that  seems  to  be  most  natural  to  meet  the 
demands  of  occlusion,  for  with  it  we  can  have  control  of  the  entire 
dental  apparatus — something  impossible  in  the  use  of  the  innumerable 
appliances  that  have  been  devised  for  the  correction  of  symptoms  only, 
without  regard  for  the  laws  of  occlusion.  He  who  will  study  its  possi- 
bilities will  be  more  and  more  impressed  with  its  wonderful  efficiency 
and  great  sim])lieity. 

Combination  Reinforced. — The  elasticity  of  the  arch  is  sufficient 
to  exert  ample  force  for  widening  either  of  the  dental  arches ;  yet  in 
very  rare  instances,  where  the  patient  has  reached  maturity,  the  force 

Fio.  680. 


may  not  be  sufficient  to  accomplish  the  desired  movements  as  rapidly 
as  may  be  wished.  To  meet  this  limitation  the  arch  may  be  reinforced 
by  one  of  the  levers  L,  which  should  be  adjusted  to  exert  pressure  upon 
the  lingual  surfaces  of  the  anchor-bands,  as  in  Figs.  687  and  689,  and 
attached  on  each  side  by  uniting  two  short  tubes,  R  and  D,  at  right 
angles,  the  longer  one  slipped  over  the  end  of  the  screw  of  the  D  band, 
and  the  ends  of  the  lever  bent  sharply  at  right  angles  and  made  to 
engage  the  short  tubes.  Any  desired  degree  of  force  may  be  easily 
gained  with  this  simple  method  of  reinforcement. 

A  simpler  way  of  securing  the  reinforcement  spring  is  to  insert  its 
finely  pointed  ends,  bent  sharply  outward  at  right  angles,  into  very 
delicate  perforations  made  in  the  anchor-bands  at  their  mesio-lingual 
angles,  as  in  Fig.  738,  the  ends  passing  through  the  band  and  extend- 
ing between  enamel  and  band. 

In  Fig.  689  the  threaded  ends  of  the  arch  are  seen  to  project  through 


MISCELLA  NEO  US  CO  MB  IN  A  TIONS. 


765 


the  distal  ends  of  the  sheath.  This  is  wrong.  These  ends  should  be 
clipped  oif  even  with  the  ends  of  the  sheaths  and  the  roughened  ends 
made  smooth,  otherwise  painful  abrasions  of  the  cheeks  are  likely  to 
follow. 

Miscellaneous  Combinations. 

Traction-scre-w. — Although  there  are  many  possible  combinations 
with  the  traction-screw,  in  reality  its  uses  should  be  limited  to  two  or 
possibly  three.  Formerly  its  most  important  use  was  that  of  retraction 
of  that  most  obstinate  tooth,  the  canine,  as  shown  in  Figs.  690  and 
691,  rarely  necessary  since  the  advent  of  the  Baker  anchorage.  This 
it  accomplishes  so  easily  and  so  perfectly,  when  properly  adjusted  and 
managed,  that  it  easily  takes  rank,  we  believe,  over  all  other  appliances 
for  this  purpose. 

In  its  correct  adjustment  the  canine  and  the  anchor  tooth  are  carefully 
banded  after  the  manner  described  for  adjustment  of  the  plain  and 
anchor-bands.  The  traction-screw  is  then  held  in  position,  and  the 
short  and  long  sheaths  made  to  touch  the  bands  at  the  exact  points  they 


Fig.  690. 


Fig.  691. 


No.2 


E.H.A 


are  to  occupy  when  soldered.  With  a  suitable  instrument  the  anchor- 
band  is  scratched  parallel  with  the  long  sheath  to  indicate  its  align- 
ment. The  side  of  the  long  sheath  is  then  filed  to  permit  of  close  con- 
tact with  the  band  and  to  give  increased  surface  for  the  solder,  filing 
through  being  carefully  avoided.  The  band  is  then  replaced,  and  the 
exact  point  of  contact  of  the  edge  of  the  short  sheath  with  the  band 
on  the  canine  is  located  and  indicated  by  a  suitable  mark.  Lest  this  be 
obliterated  upon  soldering,  the  band  may  be  perforated  at  this  point 
with  a  small  drill.  Having  noted  as  accurately  as  possible  the  angle  at 
Avhich  this  sheath  shall  stand  to  properly  line  with  the  right  angle  of 
the  shaft,  minute  notches  are  made  in  the  edge  of  the  band  mesially  and 
distally,  to  line  with  the  end  of  the  sheath  (Fig.  692),  the  bands  are 
now  removed  from  the  teeth  and  the  sheaths  from  the  screw,  and  a 
minute  piece  of  solder  partially  fused  upon  the  edge  of  the  short  sheath 
at  the  point  intended  for  attachment  to  the  band.  The  sheath  is  then 
held  with  pliers  in  the  left  hand,  the  band  being  held  by  its  untrimmed 
ends  in  the  right  hand,  the  end  of  the   sheath  lining  with  the  notches 


7<i()  ORTHODONTIA. 

A  and  B,  Fig.  692,  and  the  soUUt  fiist-d  In-  contact  w  itli  the  Hame  at 
the  proper  point. 

It  is  highly  essential  that  the  sheath  shall  be  attached  at  the  right 
point  and  at  thi!  proper  angle,  or  the  angle  of  the  screw  will  not  fit. 

Be  it  remembered  that  the  sheath  attached  to  the  canine  band  must 
always  stand  at  right  angles  to  the  long  axis  of  the  tooth,  that  a  free 
hingc-lik<'  niovcnicnt  of  the  tooth  in  retraction  may  be  gained  ;  not 
parallel  with  the  long  axis,  as  some  will  persist  in  attaching  it,  with 
resultant  binding  and  prevention  of  free  movement. 

The  surplus  ends  of  the  band  are  now  trimmed  off  and  smoothed, 
and  the  band  deoxidized  and  cemented  in  position.  While  the  cement 
is  hardening  the  long  sheath  is  soldered,  according  to  alignment,  to  the 
No.  2  band.  It  is  then  cleansed  and  slipped  upon  the  screw  and  the 
nut  adjusted,  the  angle  is  hooked  into  the  sheath  upon  the  canine  band, 

Fig.  692. 


and  the  clamp-band  slipped  over  the  crown  of  the  molar  and  gently 
tightened.  It  is  allowed  to  remain  a  day  or  two  before  cementing,  in 
order  that  this  operation,  so  important  to  thoroughly  perform,  may  be 
accomplished  without  interference  by  pressure  from  the  approximal 
teeth,  and  also  that  both  the  canine  and  the  anchor  tooth  may  slightly 
move  and  become  more  perfectly  adjusted  to  their  relations  with  the 
two  bands. 

The  proper  length  of  the  screw  having  been  determined,  it  is  cut 
off  behind  the  nut.  Heat  must  in  no  instance  come  in  contact  with 
any  portion  of  the  shaft  of  the  screw. 

Before  finally  cementing  the  molar  band  in  position  it  should  be 
removed,  and  it  and  the  crown  of  the  molar  thoroughly  cleansed  and 
dried.  The  crown  being  properly  protected  from  moisture,  cement  is 
mixed  to  the  correct  consistence  and  the  interior  of  the  band  nearly 


MISCELLANEOUS  COMBINATIONS.  767 

filled.  The  angle  of  the  traction-screw  is  then  inserted  into  the  short 
sheath,  and  the  anchor-band  and  cement  carried  down  over  the  crown 
of  the  molar  with  the  thumb  and  finger,  forcing  the  cement  well  down 
by  pressure  from  the  thumb.  The  band  is  quickly  worked  to  the 
desired  position,  and  the  nut  of  the  band  tightened  until  it  is  firmly 
clamped.  The  superfluous  cement  is  then  wiped  off,  and  the  patient 
dismissed  until  the  next  sitting  before  tightening  of  the  nut  of  the 
traction-screw  is  begun,  in  order  that  the  cement  shall  become  thor- 
oughly set  and  the  most  rigid  possible  attachment  gained. 

If  the  operation  thus  far  has  been  carefully  performed,  the  nearest 
approach  to  stationary  anchorage  possible  to  obtain  in  the  mouth  will 
have  been  gained,  so  that  the  canine  may  be  moved  distally  without 
changing  the  relation  of  the  occlusal  planes  of  the  anchor  tooth  with 
those  of  the  opposite  jaw.  It  is  very  important,  however,  not  to  strain 
the  attachment  by  overtightening  of  the  nut  of  the  traction- screw  at 
any  time.  One-half  a  revolution  of  the  nut  each  day,  or  just  enough 
to  exert  a  slightly  snug  feeling  upon  the  canine,  is  all  the  force  that 
should  be  exerted  at  any  one  time. 

It  is  very  important  that  the  angle  of  the  screw  be  passed  into  the 
sheath  its  full  length,  otherwise  it  will  be  broken  when  force  is  exerted. 

If  it  is  desired  to  rotate  the  canine  as  it  is  moved  distally,  it  may  be 
accomplished  by  using  a  staple  instead  of  a  sheath  for  engaging  the 
angle  of  the  traction-screw,  as  shown  in  Fig.  693.  In  t^is  instance  the 
angle  of  the  screw  is  parallel  with  the  long  axis  of  the  tooth,  instead 
of  at  right  angles  to  it,  as  when  the  tube  is  used.  In  this  manner  force 
is  exerted  on  one  side  of  the  band  only,  and  rotation  as  well  as  retrac- 
tion takes  place. 

In  some  instances  it  may  be  desirable  to  operate  the  screw  on  the 
lingual  side  of  the  arch,  although  the  anchorage  is  not  so  secure,  on 
account  of  the  shape  of  the  crown  not  admitting  of  so  strong  attach- 
ment of  the  sheath  to  the  band. 

The  shifting  of  the  cuspid  lingually  or  labially  in  its  distal  move- 
ment may  be  accomplished  by  bending  the  screw  where  it  enters  the 
sheath.  As  the  nut  is  tightened  the  screw  is  gradually  straightened  as 
it  is  drawn  into  the  sheath,  thus  arranging  the  teeth  in  proper  align- 
ment. 

Fig.  693  shows  the  use  of  a  traction-screw  in  effecting  rotation  of  a 
premolar  tooth  in  combination  with  the  clamp-bands  Nos.  1  and  2. 
The  angle  of  the  screw  engages  a  staple  made  of  the  G  wire  soldered 
to  the  mesio-lingual  angle  of  the  band  encircling  the  premolar.  By 
tightening  the  nut  at  A,  traction  force  is  exerted  on  one  side  only,  while 
resistance  in  the  opposite  direction  is  offered  by  the  intervening  pre- 
molar.    The  great  power  thus  exerted  makes  this  the  most  efficient 


7()8 


ORTHODONTIA. 


method  known  of  rotatini;  a  premolar,  and  is  one  that  is  occasionally 
used  by  the  writer,  always  with  much  satisfaction,  hut  only  used  when 
a  sinij:lo  tooth  is  i^rcatly  turned  upon  its  axis,  and  in  cases  belonging  to 
the  tirst  division  of  ("lass  II.,  where,  after  all  the  other  teeth  have  been 
moved  into  their  normal  relations,  it  is  desirable  to  remove  tiie  expan- 
sion arch  and  eti'ect  retenti(»n,  when  rotation  of  this  tooth  may  be  fin- 
ished, as  here  deseribed.  In  such  cases  the  expansion  arch  may  be 
used  at  the  same  time,  in  combination  with  this  appliance,  in  wliich 
ease  the  elamp-band  I)  would  be  adjusted  to  the  second  molar.  Of 
course,  all  ordinary  rotation  of  premolars  would  be  effected  in  the  usual 
way,  or  by  means  of  plain  spurred  bands,  wire  ligatures,  etc.,  in  com- 
bination with  the  expansion  arch. 

In  Fig.  694  is  shown  another  use  of  the  traction-screw  in  effecting 
the  labial  movement  of  a  lateral,  and  at  the  same  time  providing  space 


Fui.  693. 


Fui.  (!94. 


D 


E.H.  A 


E.H.A. 


for  its  movement.  A  strip  of  band  material  F  is  looped  around  the 
lateral,  the  ends  resting  on  the  labial  surfaces  of  the  adjoining  teeth. 
To  one  end  is  soldered  vertically  one  of  the  short  tubes  D,  while  on  the 
other  end  is  a  similar  tuljc  attached  horizontally.  Into  these  tubes  the 
traction-screw  is  placed,  being  bent  to  conform  to  the  proper  curve  of 
the  arch,  and  pushes  the  ends  of  the  band  farther  apart  as  the  nut  is 
tightened.  This  combination  is  now  practically  obsolete  for  the  move- 
ment of  the  lateral,  as  here  described,  or  for  any  of  the  front  teeth,  the 
same  movements  being  far  more  easily  accomplished  by  means  of  the 
expansion  arch.  Yet  it  is  valuable  on  rare  occasions  for  moving  buc- 
cally  a  premolar  that  is  in  marked  lingual  occlusion,  as  in  Fig.  702, 
as  it  effectually  ])rovides  space  for  the  tooth  while  moving  it  buccally. 
When  so  used  the  screw  is  left  straight,  lying  close  against  the  buccal 
surfaces  of  the  teeth. 

Fig.  695  shows  a  combination  of  traction-screw  and  expansion  arch 


MISCELLANEOUS  COMBINATIONS. 


769 


for  shortening  one  of  the  lateral  halves  of  the  dental  arch,  and  at  the 
same  time  correcting  malpositions  of  the  teeth.  This  combination  is 
now  rarely  necessary,  since  normal  occlusion  is  the  object  in  treatment, 
and  the  advent  of  the  Baker  anchorage  has  made  this  possible,  thus 
practically  eliminating  the  necessity  for  extraction. 

The  traction-screw  should  be  first  adjusted,  as  already  described,  and 
in  addition  it  should  be  provided  with  one  of  the  tubes  D  soldered  to 
the  side  of  the  sheath  Y,  near  its  mesial  end.  This  is  for  the  reception 
and  support  of  one  end  of  the  expansion  arch  in  place  of  the  usual  D 
or  X  band.  The  nut  of  the  expansion  arch  is  to  bear  against  this  tube, 
and  when  so  used  the  nut  should  be  reversed,  the  extension  flange  turned 
mesially.  The  other  end  of  the  expansion  arch  is  supported  in  the  usual 
way,  as  in  Fig.  685.  As  the  canine  is  retracted  into  the  space  made 
vacant  by  the  loss  of  the  first  premolar,  the  malposed  incisors  are  rotated 

Fig.  695. 


by  means  of  the  ligatures,  bands,  and  spurs,  as  is  well  shown  in  the 
engraving  and  also  in  Fig.  687. 

A  similar  combination  may  be  used  on  the  opposite  side  of  the  arch 
when  it  is  desirable  to  shorten  both  of  the  lateral  halves,  and  the  Baker 
anchorage  may  be  used  to  reinforce  the  expansion  arch. 

Jack-screw. — Since  the  jack-screw  was  introduced  for  orthodontic 
purposes  by  Dr.  Dwindle,  it  has  been  much  employed  by  dentists,  prob- 
ably owing  to  its  simplicity  and  great  power,  and  it  was  formerly  a  very 
important  part  in  many  of  the  combinations  of  the  writer's  appliances. 
Notwithstanding  that  he  believes  he  is  the  author  of  by  far  the  most 
perfect  form  of  jack-screw  yet  given  to  the  profession,  and  one  that  is 
widely  used  and  often  imitated,  he  believes  that  in  the  requirements  of 
modern  orthodontia  it  is  one  of  the  poorest  of  appliances  and  that  its 
use  should  be  practically  discontinued,  it  having  been  superseded  by  the 
expansion  arch,  for  practically  all  of  the  movements  possible  to  accom- 
plish with  the  jack-screw  are  better  and  more  easily  performed  with  the 
49 


770 


ORTHODONTIA. 


expansion  arch.  With  tho  hitter  we  have  iiulivichial  and  oollective  con- 
trol over  the  teeth,  and  complete  control,  also,  over  the  force  exerted, 
while  with  the  jack-screw  we  do  not  have  control  over  the  force. 

Yet  there  is  one  movement  for  which  the  jack-screw  has  been  found 
almost  a  necessity  in  a  few  cases.  It  is  in  the  adjustment  of  that  ex- 
tremely difficult  tooth  to  move,  a  badly  inlocked  upper  canine,  especially 
when  it  fails  to  fully  erupt. 

In  some  cases  the  writer  has  found  all  of  the  upper  teeth  to  become 
displaced  when  used  by  means  of  the  arch  as  anchorage  to  effect  the 
movement  of  such  a  canine.  In  such  cases  the  jack-screw,  used  and 
reinforced  as  in  Fig.  696,  in  the  similar  movement  of  a  lateral  incisor, 
in  combination  with  the  expansion  arch,  will  be  found  valuable. 


Fig.  696. 


Fig.  697. 


E.H.A. 


In  this  case  an  anchor-band  provided  with  a  spur  of  G  wire  engages 
the  end  of  the  jack-screw.  The  flattened  end  of  the  screw  is  notched 
and  engages  a  staple  soldered  to  the  lingual  surface  of  a  band  on  the 
tooth  to  be  moved.  The  end  of  the  jack-screw,  sharpened  to  a  needle- 
like point  and  made  to  engage  a  pit  drilled  into  the  enamel  of  the  canine 
to  be  moved,  may  sometimes  be  a  most  desirable  method  of  securing  it. 

Lever. — The  piano-wire  lever  L  also  formerly  played  an  important 
part  in  the  combinations  of  the  writer's  appliances  for  accomplishing 
rotation  of  the  teeth.  It  also  has  been  superseded  by  the  expansion 
arch,  for  reasons  already  given  for  the  discontinuance  of  the  use  of  the 
jack-screw. 

In  some  in.stances,  however,  it  is  valuable  ;  for  example,  after  teeth 
have  been  rotated  and  have,  through  the  carelessness  of  the  patient, 
partially  relapsed,  they  may  be  easily  readjusted,  as  it  requires  but  little 
force,  by  means  of  a  band  provided  with  a  tube  R  for  the  insertion  of 
the  power  end  of  the  lever,  the  long  end  being  sprung  around  and 
attached  to  a  premolar  band,  as  shown  in  Fig.  697,  or,  what  is  equally  as 
good,  a  simple  wire  ligature  engaging  tooth  and  lever. 


MISCELLANEOUS  COMBINATIONS. 


771 


Double  rotation,  as  shown  in  Figs.  698,  699,  and  700,  may  also  be 
accomplished  by  means  of  the  lever  made  to  exert  force  by  engaging 
tubes,  or  spurs  and  ligatures,  as  shown  in  the  engravings ;  but  we  insist 
that  they  should  rarely,  if  ever,  be  employed  in  the  first  adjustment  of 


Fig.  698. 


Fig.  699. 


Fig.  700. 


the  teeth,  as  teeth  in  these  positions  are  only  symptoms  or  results  of 
pressure  exerted  laterally  by  adjoining  teeth.  For  this  reason  the  ex- 
pansion arch,  acting  upon  all  of  the  teeth,  thus  providing  spaces  for  the 
moving  teeth,  as  well  as  effecting  their  movement,  is  best.     But,  as  we 


Fig.  701. 


Fig.  702. 


have  said,  for  teeth  that  have  partially  relapsed  these  are  simple  and 
efficient  ways  of  readjusting  them. 

In  Fig.  701  two  tubes  or  spurs  attached  to  bands  at  the  mesio-labial 
angles  of  the  upper  centrals  are  being  drawn  closer  together  by  means, 


Fig.  703. 


EHfl 


of  the  wire  ligatures,  force  in  the  opposite  direction  being  exerted  upon 
these  teeth  by  a  wedge  of  rubber  resting  in  contact  with  their  mesio- 
labio-gingival  angles. 

Another,  simple  but  often  useful  little  appliance  is  shown  in  Fig. 
702,     A  section  of  the  G  wire  is  either  soldered  directly  to  a  clamp- 


772  ORTHODONTIA. 

hand  or  held  in  position  by  means  of  a  tnhe  soldered  to  the  hand,  \\\v 
other  end  allowed  to  rest  loose  against  a  tooth  to  assist  in  the  anchorage 
in  moving  out  an  inloeked  tooth  hy  means  of  a  rubber  or  wire  ligature, 
the  latter  preferred. 

Fig.  703  shows  the  simplest  of  all  regulating  devices,  yet  one  that  is 
very  efficient  and  valuable,  especially  in  widening  the  distance  between 
deciduous  canines,  as  here  shown,  to  release  lateral  pressure  ujwn  erupt- 
ing permanent  incisors. 

It  consists  of  a  section  of  G  wire,  the  ends  sharpened  and  made  to 
rest  in  delicate  pits  in  the  enamel  of  deciduous  cusj)ids.  Irresistible 
force  is  brought  to  bear  on  these  teeth  by  an  occasional  ])inch  of  this 
wire  with  the  regulating  pliers,  which  lengthens  the  wire.  The  teeth 
so  moved  will  act  through  their  inclined  planes  upon  the  uj)per  canines, 
and  in  like  manner  effect  their  buccal  movement,  thereby  releasing  press- 
lu'c  from  the  upper  permanent  incisors.  As  here  described,  it  is  useful, 
of  course,  only  on  young  patients,  and  the  wire  ])inehed  only  at  long 
intervals,  say  a  month  intervening.  The  same  })rineiple,  however,  is  often 
made  use  of  by  the  writer  in  older  patients.  In  these  cases  a  thoroughly 
annealed  section  of  one  of  the  expansion  arches  is  used,  its  end  secured 
by  solder  to  bands  cemented  upon  the  canine  teeth. 

Retention. 

After  malposed  teeth  have  been  moved  into  the  desired  positions,  it 
is  of  the  greatest  importance  that  they  l)e  mechanically  supported  imtil 
all  tendency  to  return  to  their  former  malpositions  has  subsided ;  but  it 
cannot  l)e  too  strongly  insisted  upon  that  unless  such  occlusion  has  been 
estal)lished  as  will  enable  the  inclined  planes  of  the  cusps  to  ultimately 
act  in  harmony  for  mutual  support,  permanency  of  the  teeth  in  their 
new  positions  after  the  retaining  devices  have  been  removed  cannot  be 
hoped  for.  It  should  be  borne  in  mind  that  all  retaining  devices  are 
only  temporary  assistants  to  the  permanent  establishment  of  the  normal 
functions  of  the  occlusal  planes  of  the  teeth. 

Time  Required  for  Retention. — The  time  required  for  mechanical 
retention  varies,  according  to  the  age  of  the  patient,  occlusion,  tooth 
movements  accomplished,  length  of  cusps,  health  of  tissues,  etc.,  from  a 
few  days  to  a  year  or  two  years,  or  even  longer,  while  perhaps  in  rare 
instances  retention  may  be  required  for  an  ind(>finite  period.  Upper 
incisors  which  have  been  moved  from  lingual  to  normal  occlusion,  as  in 
Fig.  707,  require  retention  for  a  few  days  only,  as  the  occlusion  with 
the  lower  incisors  permanently  supports  them  in  their  new  positions. 

Again,  the  support  of  teeth  that  have  been  directed  into  correct 
positions  during  the  period  of  eruption  is  usually  required  for  a  few 
months  only,  while  a  much  longer  period  (for  at  least  a  year)  would  be 


RETENTION,  773 

required  for  the  same  teeth  if  moved  after  the  full  development  of  their 
alveoli. 

Again,  owing  to  the  great  disturbance  of  the  fibres  of  the  peridental 
membrane  of  a  tooth  which  has  been  rotated,  its  retention  requires  a 
far  longer  time  than  if  the  movements  labially  or  lingually  had  been 
accomplished. 

A  rule  of  general  application  may  be  made,  that  three  times  the 
length  of  time  will  be  required  for  retention  of  teeth  of  patients  aged 
twenty-one  as  for  those  of  patients  aged  twelve,  the  same  tooth  move- 
ments having  been  performed. 

There  is  usually  a  temptation  to  remove  the  appliances  before  the 
teeth  have  become  thoroughly  established,  and  many  are  the  failures 
from  this  cause  of  otherwise  well-conducted  cases.  As  so  much  depends 
upon  this  part  of  the  operation,  it  is  far  better  that  the  appliances 
should  be  worn  longer  even  than  necessary,  rather  than  that  they  be 
too  early  removed. 

Unless  the  conditions  which  have  been  operative  in  producing  or 
maintaining  mal-occlusion  be  removed  or  modified,  the  establishment 
of  permanent  normal  occlusion  can  rarely  be  hoped  for.  For  example, 
if  mal-occlusion  is  the  result  of  mouth-breathing,  it  will  be  very 
improbable  that  the  teeth  will  remain  in  correct  occlusion  after  removal 
of  the  retaining  devices  unless  normal  breathing  be  established.  Or, 
if  malpositions  of  the  teeth  be  due  to  pathological  conditions  of  the 
gums  or  peridental  membrane,  unless  the  tissues  be  restored  to  health 
permanent  normal  occlusion  cannot  be  hoped  for.  Or  if,  by  the  loss  of 
some  one  or  more  teeth,  as,  for  example,  the  first  molars,  faulty  occlu- 
sion result  from  the  tipping  of  the  remaining  teeth,  the  further  unfavor- 
able movement  of  these  teeth  must  be  permanently  arrested  by  crowns 
or  bridges,  or  other  methods  of  replacing  the  missing  teeth  by  artificial 
substitutes. 

Principles  of  Retention. — As  the  tendency  of  teeth  that  have  been 
moved  into  occlusion  is  to  return  to  their  former  malpositions,  the  main 
principle  to  be  considered  by  the  designer  of  a  retaining  device  is  the 
antagonizing  of  the  teeth  in  the  directions  of  their  tendencies  only. 
Very  slight  antagonism  is  required,  but  its  exercise  must  be  constant. 
If  the  student  will  keep  this  principle  in  view  he  will  realize  that  only 
delicate  devices  are  necessary,  and  will  be  impressed  with  the  utter  use- 
lessness  of  much  of  the  bulk  and  material  composing  so  many  of  the 
retaining  devices  shown  in  our  literature. 

With  this  in  view,  each  corrected  case  should  be  carefully  studied 
in  connection  with  the  original  models,  noting  the  various  directions  in 
which  the  teeth  are  inclined  to  move. 

To  secure  retention  we  have  at  our  disposal  support  or  anchorage 


774  ORTHODONTIA . 

from  the  following  sources:  first,  reciprocal,  or  the  pitting;  of  one  tooth 
against  another,  their  tendencies  being  to  move  in  opposite  or  ditt'erent 
directions  ;  second,  teeth  already  firm  in  the  arcli  ;  thinl,  occipital  ;  and 
fourth,  and  most  important  of  all,  the  occlusion  of  the  teeth. 

As  the  retaining  device  is  to  be  worn  for  a  considerable  time,  some 
])refer  its  construction  from  gold  instead  of  nickel  silver,  on  account  of 
the  tendency  of  the  latter  to  discolor  in  some  mouths;  hut  it  is  a  fact, 
which  anyone  may  verify  by  experiment,  that  bands  of  the  same  deli- 
cacy will  give  far  less  trouble  by  loosening  if  made  of  nickel  silver  than 
if  made  of  gold  or  silver,  or  of  any  other  of  the  alloys. 

The  appliances  necessary  for  retaining  the  teeth  need  never  l)e  biilkv 
nor  complicated,  nor  comprise  a  large  number  of  piec^es.  We  must 
remember  that  the  patient  is  probably  already  wearied  with  the  incon- 
venience of  the  regulating  appliances,  so  it  should  be  the  aim  to  make 
the  retaining  devices  as  delicate,  compact,  and  inconspicuous  as  possible, 
always,  however,  consistent  with  the  main  object — ])erfect  support. 
The  more  securely  the  teeth  are  held,  the  more  rapidly  will  they  become 
firm  in  their  new  positions.  For  this  reason,  and  that  they  may  be  as 
little  as  possible  under  the  control  of  the  patient,  the  ap])liances  should 
be  made  stationary  by  the  attachment  of  accurately  fitted  and  cemented 
bands  whenever  practicable.  They  should  also  be  readily  cleansible 
by  the  patient  with  the  brush,  that  they  may  in  no  way  injure  the  teeth, 
no  matter  how  long  worn.  It  is  remarkable  how  compact,  simple,  and 
yet  efficient  the  retaining  devices  may  be  made,  even  for  the  most  com- 
plicated conditions. 

Temporary  Retaining  Devices. — Before  adjusting  the  retaining 
device,  it  is  often  best  to  allow^  the  regulating  appliances  to  remain 
passively  in  position  upon  the  teeth  for  several  days,  in  order  that  tlia 
tenderness  of  the  teeth  may  subside.  Yet  upon  the  removal  of  the 
regulating  appliances  there  is  usually  found  to  be  more  or  less  soreness, 
as  well  as  mobility,  in  the  teeth.  It  is,  therefore,  difficult  or  impossible 
to  form  and  fit  l)ands  with  anv  consideral)le  degree  of  accuracy  without 
occasioning  pain,  and  pain  may  and  should  be  avoided.  So  it  is  best  to 
adjust  a  temporary  device  on  exactly  the  same  principles  as  if  it  were 
to  be  permanent,  with  looser  fit  of  bands,  which  may  be  gently  worked 
into  position  with  the  fingers  alone.  If  a  good  quality  of  cement  be 
used  the  device  will  be  firmly  held  in  position  for  a  few  weeks,  until  all 
soreness  shall  have  subsided,  wdien  a  device  with  bands  and  all  other 
parts  of  the  most  perfect  fit  and  finish  may  be  substituted. 

Another  satisfactory  plan  for  temporary  retention,  after  removing 
the  expansion  arch  and  thoroughly  cleansing  the  teeth,  is  to  weave  a 
strand  of  the  wire  ligatures  about  the  teeth,  engaging  the  spurs  upon 
the  bands  which  have  been  used  in  effecting  the  various  tooth  move- 


RETENTION.  775 

ments,  and  in  this  way  antagonizing  the  teeth  in  the  direction  of  their 
tendencies. 

This  is  an  excellent  method  of  temporary  retention,  and  in  its  use 
there  are  great  opportunities  for  the  display  of  judgment  and  skill. 

Figs.  704,  705,  and  706  show  a  case  where  this  style  of  temporary 
retention  has  been  employed  in  resisting  the  tendency  of  the  central  and 
lateral  incisors  to  return  to  positions  of  torso-occlusion. 

In  the  movement  of  these  teeth  from  their  torso-mesial  positions, 
bands  had  been  made  to  encircle  their  crowns  with  spurs  placed  at  the 
gingival  edge  of  the  bands,  at  their  disto-lingual  angles  to  operate  in 
connection  with  the  expansion  arch,  wire  ligatures,  etc.  In  the  tem- 
porary retention  three  ligatures  were  employed.  First,  one  ligature  was 
made  to  engage  the  spurs  on  the  central  incisors,  both  ends  brought 
forward  and  tightly  twisted  at  the  mesio-labial  angles  of  the  centrals. 
Thus  it  will  be  seen  that  reciprocal  force  is  exerted  that  will  effectually 
resist  the  movement  of  these  teeth  in  the  direction  of  their  tendencies. 
Second,  a  wire  ligature  was  made  to  engage  the  spur  on  the  disto-lingual 
angle  of  the  left  central  incisor,  the  ends  brought  forward  across  its  labial 
surface,  one  end  being  passed  between  the  central  and  lateral  and  made 

Fr«.  704.  Fig.  705,  Fig.  706. 


to  engage  the  spur  upon  the  left  central,  brought  back  between  these 
teeth,  and  firmly  twisted  with  the  other  end  of  the  strand  of  ligature  at 
a  point  on  the  labial  surface  of  the  lateral  incisor,  as  indicated.  In 
precisely  the  same  manner  a  ligature  was  made  to  engage  the  spurs  upon 
the  right  lateral  and  centi'al,  all  as  shown  in  Fig.  705.  By  studying  the 
original  positions  of  the  teeth  in  Fig.  704,  it  will  be  seen  how  direct  and 
positive  is  the  reciprocal  force  exerted  by  these  ligatures  in  resisting  the 
movement  of  the  teeth  in  the  direction  of  their  tendencies. 

After  a  few  weeks  of  temporary  retention  the  teeth  were  permanently 
retained,  as  shown  in  Fig.  706,  by  other  bands  placed  upon  the  laterals 
and  connected  by  a  section  of  the  G  wire  in  the  usual  way,  as  described 
elsewhere. 

Permanent  retention,  or  devices  that  are  to  be  worn  permanently 
or  during  the  entire  time  of  mechanical  retention.  The  simple  band 
and  the  short  projecting  wire,  which  for  convenience  we  call  a  spur, 
form  the  basis  of  a  principle  which  is  applicable  to  nearly  all  the 
requirements  of  permanent  retention  in  all  the  various  classes.  It  is 
surprising  to  find  in  what  number  of  combinations  the  band  and  spur 


77G 


ORTHODONTIA. 


may  be  employed.  If  a  single  tooth  has  been  rotjited,  it  may  be  pre- 
vented from  returning  to  its  former  position  (or  antagonized  in  the 
direetion  of  its  tendency)  by  a  band  with  two  spurs,  as  in  Fig.  707. 
These  may  be  soldered  directly  to  the  band.  Unnecessarily  long  spurs 
should  never  be  used,  as  they  are  cumbersome  and  unsigiitlv.  Even 
.shorter  spurs  than  those  shown  in  the  engraving  may  be  employed. 

Much  care  should  be  exercised  in  placing  the  points  of  the  spurs 
which  bear  against  the  adjoining  teeth  so  that  they  will  not  cause  dis- 
placement of  the  tooth  retained.  If  placed  as  shown  in  the  engraving, 
the  elevation  of  the  lateral  in  its  socket  would  be  inevitable,  on  account 


of  the  inclined  planes  down  which  the  spur  will  be  made  to  slide  by 
the  tooth  in  its  tendency  to  return  to  its  original  position.  (This  point 
may  be  taken  advantage  of,  however,  in  some  cases  where  it  is  desirable 
to  force  the  eruption  of  a  tooth  slightly  ;  for  example,  a  canine.)  The 
point  of  the  spur  in  the  case  shown  should  bear  upon  the  gingival  ridge 
of  the  central,  while  the  point  of  bearing  upon  the  canine  should  be 
above  the  swell  of  the  crown.  The  fine  adjustment  of  the  spurs  should 
be  left  until  the  cement  has  hardened  after  setting  the  band,  when  they 
may  be  bent  until  their  ends  touch  at  the  exact  points  required. 


Fig.  708. 


Fig.  709. 


E.H.A. 


In  some  instances  where  the  period  of  retention  is  to  be  protracted, 
or  where  bands  would  be  unpleasantly  conspicuous,  spurs  may  be  set  in 
fillings,  as  in  Fig.  708,  to  be  drilled  for  the  purpose,  or  newly  placed  if 
any  convenient  cavities  exist.  In  the  case  of  deciduous  teeth  soon  to 
pass  away,  spurs  may  be  cemented  in  cavities  drilled  for  the  purpose  in 
the  enamel,  in  j)roference  to  the  setting  of  bands. 

A  method  often  desirable  when  the  space  of  a  lost  tooth  is  to  be  pre- 
served is  to  insert  between  two  bands  a  short  section  of  G  wire,  its  ends 
being  engaged  in  tubes  R  soldered  to  the  bands,  as  in  Fig.  709. 

Another  excellent  modification  of  this  plan  is  shown  in  Fig.  710,  in 


RETENTION. 


m 


which  one  band  is  dispensed  with,  one  end  of  the  section  of  wire  G  being 
bent  in  the  form  of  a  goose-neck  to  engage  the  mesial  surface  and  sulcus 
of  the  first  premolar,  the  other  end  being  soldered  directly  to  a  plain 
band  on  the  lateral  incisor. 

If  two  approximating  teeth  have  been  rotated  in  opposite  directions, 
the  firmest  support  is  given  by  uniting  a  spur  to  the  lingual  surfaces  of 
both  bands  by  solder,  in  which  case  it  be- 
comes two  bands  and  two  spurs  united.  The 
spring  of  the  spur  makes  possible  a  greater 
precision  in  the  adjustment  of  the  bands, 
with  less  liability  of  subsequent  loosening, 
than  when  the  bands  are  united  directly  by 
solder. 

The  tendency  to  rotation  of  the  right  cen- 
tral and  lateral  incisors,  plus  the  lingual 
tendency  of  the  left  central  and  the  mesial 
tendency  of  all,  is  effectually  resisted  by 
two  bands  connected  by  a  spur,  with  an 
additional  spur  made  to  bear  upon  the  mesio-labial  angle  of  the  lateral, 
as  in  Fig.  711.  The  engraving  shows  the  ends  of  the  wire  G  secured  by 
engaging  tubes  soldered  to  the  lingual  surfaces  of  the  bands.  Direct 
attachment  of  the  ends  of  the  wire  to  the  bands  by  solder  may,  of 
course,  also  be  used,  and  is  often  preferable.  By  studying  the  tendency 
of  the  teeth,  it  will  be  seen  how  effectually  they  are  resisted  by  this 
device. 

Fig.  712  shows  the  union  of  two  bands  by  a  section  of  G  wire,  em- 
ployed to  antagonize  the  lingual  tendency  of  two  lateral  incisors  which 


E.H.A. 


Fig.  711. 


Fig.  712. 


Fig.  713. 


E.KA. 


have  been  moved  labially  into  the  line  of  occlusion,  while  another  com- 
bination of  bands  and  spurs  (Fig.  713)  attached  to  the  centrals  would 
accomplish  the  same  result. 

Another  very  useful  plan  for  accomplishing  the  same  result  is  to 
solder  a  section  of  G  wire  directly  to  the  labial  surface  of  a  band  on 
each  lateral,  the  ends  being  made  to  rest  against  the  labial  surfaces  of 
cuspid  and  central. 

Still  another  plan  of  much  value,  now  often  used,  is  to  dispense  with 


778 


ORTHODONTIA. 


the  mesial  spur  and  continue  the  distal  spur  across  the  labial  surface  of 
the  canine  and  tirst  premolar,  it  beinj;  ligated  io  the  latter  by  means  of 
a  neatly  twisted  wire  ligature,  very  valuable  in  such  cases  as  that  shown 
in  Fig.  739,  for  not  only  are  the  lingual  and  rotatory  tendencies  of  the 
lateral  effectually  antagonized,  but  also 
the  labial  tendency  of  the  canine  and 
lingual  tenden(T  of  the  first  premolar. 
\^  a  number  of  teeth  require  sup- 
port, it    may  be  readily  accomplished 

Fio.  714. 


Fiu.  715. 


by  the  same  principle  extended  to  include  the  union  of  two  bands  by 
a  spur. 

Fig.  714  shows  the  union  of  two  bands  by  a  section  of  G  wire,  which 


Fig.  717. 


not  only  accomj)lished  the  sam^  result,  l)ut  would  also  resist  lateral 
pressure  or  rotation  of  one  or  both  of  the  canines  if  required,  while  an 
additional  spur  soldered  to  the  long  spur,  as  in  Fig.  716,  forms  another 


BETENTION.  779 

combination  for  antagonizing  the  various  tendencies  of  the  incisors 
and  canines. 

By  the  addition  of  two  spurs  to  this  combination,  as  in  Figs.  718 
and  719,  the  lingual  and  buccal  tendencies  of  the  first  premolars  are  also 
resisted  in  a  complicated  case  of  mal-occlusion. 

It  will  be  seen  that  any  or  all  of  the  incisors  and  canines  may  be 
firmly  supported  by  combinations  of  the  band  and  spur,  and  that  the 
premolars  and  molars  may  be  included  by  extending  the  principle,  but 
its  greatest  usefulness  is  limited  to  the  incisors  and  canines,  or  at  most 
extended  to  include  the  first  premolars,  as  in  Fig.  718.  If,  however,  a 
single  premolar  shall  have  been  rotated,  or  if  a  single  molar  or  premolar 
shall  have  been  moved  lingually  or  buccally,  the  band  and  double  spur 
made  to  bear  against  the  adjoining  teeth,  the  same  as  already  described 
for  retention  of  an  incisor,  will  be  most  efficient. 

For  the  retention  of  canines  that  have  been  retracted,  of  course  noth- 
ing could  be  more  efficient  than  to  allow  the 
traction-screws  to  remain  in  position  as  re-  Fig. 

tainers,  which  should  usually  be  done  for  at 
least  two  months.  This  is  only  another  form 
of  the  principle  of  two  bauds  and  spurs  united. 
As  the  device  is  more  bulky  than  is  neces- 
sary, it  may  be  removed  after  the  time  stated, 
and  the  following  plan  for  protracted  reten- 
tion of  these  teeth  be  employed  :  A  delicate 
plain  band  is  made  to  encircle  the  second  pre- 
molar, having  two  tubes  R  soldered,  one  to 
the  mesio-lingual  and  one  to  the  mesio-buccal 
angles  of  the  band,  close  to  the  gum.     Ends  ^-"-a 

of  the  section  of  a  ligature  wire  are  passed 

through  these  tubes,  and  the  wire  drawn  tightly  against  the  mesial  surface 
of  the  cuspid.  The  ends  are  then  bent  sharply  around  and  clipped  off. 
Twisting  is  unnecessary.  The  device  is  correctly  shown  in  the  engrav- 
ing (Fig.  720). 

By  its  use  ample  support  is  gained  and  the  bulk  and  conspicuousness 
reduced  to  the  minimum.  It  is  important  that  the  tube  shall  be  close  to 
the  gum,  so  the  wire  loop  cannot  slide  off  the  canine  crown. 

Retention  of  a  number  of  teeth  may  be  effected  by  a  union  of  bands 
encircling  them,  as  in  Figs.  721  and  722.  This  method,  however,  is  not 
advisable,  as  much  unnecessary  space  between  the  teeth  is  thus  monopo- 
lized, while  it  is  impossible  to  hold  all  so  rigidly  together  that  one  or 
more  will  not  become  uncemented. 

In  the  use  of  all  bands   in  retention  we  would  caution  that  they 

be  inspected  at  least  once  in  two  months,  for  if  they  should  become 


780 


ORTHODONTIA. 


loosened  they  would  act  as  receptacles  for  food  particles,  the  firinontatiou 
of  whicii  might  in  time  injure  the  enamel. 

The  lintjual  tendency  of  molars  and  premolai*s  is  l)est  resisted  hy  a 
neatly  fitting  vulcanite  i)hitc,  as  in  Fig.  723,  partially  covering  the  palatal 
arch  and  bearing  against  the  teeth  that  have  been  moved. 

The  plate  should  not,  during  the  early  stage  of  retention,  extend  far 
enough  forward  to  rest  in  contact  with  the  incisors  or  canines,  for,  owing 


Fig.  7-21. 


Fig.  722. 


to  their  sloping  surfaces,  the  plate  is  wholly  unreliable  for  their  support, 
and  would  only  interfere  with  other  devices,  besides  being  of  superfluous 
i)ulk.  It  may  be  necessary  to  secure  tiie  jdate  in  position  in  some 
instances,  which  may  be  done  by  springing  each  lateral  edge  under  a  lug 
soldered  to  a  band  encircling  a  molar  or  premolar.  Such  bands  may 
usually  be  dispensed  with  after  a  short  time,  when  the  plate  has  become 
better  settled  in  position  and  the  force  exerted  by  the  teeth  less  marked. 

Fig.  723. 


A  vulcanite  plate  is  also  most  efficient  for  antagonizing  the  lingual 
tendency  of  the  lower  molars  and  premolars.  It  should  be  delicate  but 
carefully  made,  and  siiould  cover  the  lingual  surfaces  of  the  teeth,  and 
extend  but  a  short  distance  beyond  the  gingiva,  laterally,  but  rather  more 
in  the  region  of  the  incisor  gum.  Hooks  of  platinized  gold,  made  to 
engage  the  lingual  grooves  of  the  first  lower  molars,  should  be  vulcanized 
into  the  plate,  to  prevent  undue  pressure  upon  the  gum  by  the  settling  of 
the  plate. 


RETENTION.  781 

This  form  of  plate  is  also  valuable  for  retaining  the  regained  space  of 
lost  teethj  as  in  Fig.  772. 

When  two  plates  are  used,  as  here  described,  the  lower  should  be  the 
last  dispensed  with,  on  account  of  the  greater  importance  of  the  lower 
teeth  in  maintaining  the  occlusion. 

Where  the  molars  have  been  moved  distally  in  the  upper  arch  and 
mesially  in  the  lower,  as  in  the  treatment  of  cases  belonging  to  Class  II., 
they  are  retained  by  means  of  that  excellent  principle  shown  in  Fig. 
724,  consisting  of  a  strong  spur  made  to  close  in  front  of  a  plane  of 
metal,  both  soldered  to  No.  2  bands,  which  are  clamped  in  cement  on 
opposing  molars.  If  the  device  is  properly  made  and  adjusted,  only 
occasional  inspection  is  necessary  to  keep  it  in  order,  and  it  will  be 
seen  how  effectually  the  direction  of  the  tendencies  of  not  only  the  first 
molars,  but  of  all  of  the  molars  and  premolars  on  the  same  side  are 
resisted. 

The  spur  may  be  made  of  brass  or  nickel  silver,  about  one-eighth  of 
an  inch  in  diameter.  The  plane  of  metal  soldered  to  the  band  upon  the 
upper  molar  should  be  about  one-fourth  to  three-eighths  of  an  inch  long 
and  about  one-eighth  of  an  inch  wide,  best  cut  from  a  silver  ten-cent 
piece,  and  united  to  the  band  with  plenty  of  silver  solder  and  borax. 
The  finer  adjustment  of  the  spur  is  best  effected  by  bending  after  the 
cement  has  become  hardened. 

It  may  be  necessary  to  occasionally  remove  the  upper  band  and  resol- 
der  the  plane  according  to  the  needs  of  retention.  A  point  of  impor- 
tance to  be  remembered  is  that  the  plane  should  be  attached  to  the  lower 
edge  of  the  band,  so  that  there  will  be  less  leverage  upon  the  spur,  and 
consequently  less  liability  of  loosening  the  lower  band.  This  device  is 
also  shown  in  Fig.  789. 

In  rare  instances  spurs  set  in  fillings  for  accomplishing  the  same  pur- 
pose in  retention  will  be  found  indispensable. 

A  very  simple  and  efficient  retaining  device  for  upper  molars  that 
have  been  moved  from  lingual  occlusion,  and  for  lower  molars  that  have 
been  moved  from  buccal  occlusion,  as  in  Figs.  732  and  737,  is  a  band 
and  spur  placed  upon  the  upper  molar,  the  spur  or  finger  being  made  to 
bear  against  the  incline  of  the  buccal  surface  of  the  lower  molar,  or  the 
mesial  or  distal  angle  of  a  lower  molar  or  premolar.  Not  only  is  this 
device  efficient  as  a  retainer,  but  it  is  also  valuable  as  a  regulating 
device,  for  by  occasionally  bending  the  spur  to  increase  its  efficiency,  the 
buccal  movement  of  the  upper  molar  and  the  lingual  movement  of  the 
lower  may  be  accomplished  to  any  desired  distance,  or  they  may  to  some 
extent  be  shifted  mesially  and  distally  by  so  placing  the  spurs  as  to  exert 
a  mesial  or  distal  influence. 

In  like  manner  the  principle  of  plane  and  spur  may  be  employed,  and 


782 


ORTHODONTIA. 


is  often  preferable,  upon  the  premohirs,  as  in  Fig.  725,  making  use  of 
the  No.  1  chunp-bands.  In  this  case  the  spur  maybe  made  shorter,  and 
also  straight  instead  of  curved. 

Sometimes  the  principle  may  be  employetl  in  making  tiie  attachments 
to  canines.  When  so  used  no  band  and  plane  is  necessary  upon  the  upper 
canine,  advantage  being  taken  of  its  form,  its  mesial  inclined  plane  en- 
giiging  a  flat  spur  which  has  been  soldered  to  a  band  cemented  to  the  lower 
canine,  as  shown  in  Fig.  726,  This  spur  should  be  about  one-eighth  of  an 
inch  wide  where  it  engages  the  upper  canine,  and  rounded  at  its  lower  end 

Fio.  724. 


E.  U.  A. 


to  avoid  irritation  of  the  lip  where  the  spur  is  attached  to  the  band.  It 
should  incline  somewhat  forward  to  be  most  effective,  and  if  occasional 
adjustment  is  necessary,  this  may  be  easily  done  by  bending,  to  make  its 
bearing  upon  the  upper  canine  more  effective.  In  this  way  not  only  reten- 
tion, but  the  actual  movement  of  the  upper  canine  distally  and  the  lower 
canine  mesially,  may  be  accomplished  to  some  extent,  and  in  many  cases 
this  is  very  desirable. 

Owing  to  the  unfav()ral)le  shape  of  the  lower  canine  tooth,  tliere  is 
more  liability  of  bauds  upon  these  teeth  loosening  under  strain   than 


Fig.  725. 


Fig.  726. 


Fig.  727. 


K.  H.  A. 


EH   A. 


those  upon  the  premolars.  They  should  therefore  be  made  with  the 
greatest  care,  always  using  the  H  band  material,  and  securing  the  most 
perfect  fit.  This  spur  is  also  best  made  from  a  silver  ten-cent  piece. 
The  band  is  illustrated  in  Fig.  727. 

Retention  of  upper  incisors  that  have  been  reduced  from  protrusion, 
as  in  Division  1  and  its  subdivision  of  Class  II.,  may  be  successfully 
effected  by  the  plan  shown  in  Fig.  712,  made  to  extend  to  bands  which 
have  been  placed  upon  the  canines  or  first  premolars. 


TREATMENT.  783 

A  device  for  resisting  the  labial  and  lengthening  movements  of  the 
upper  incisors  is  effected  by  placing  upon  the  lower  central  incisors  plain 
bands,  having  soldered  to  their  labial  surfaces  strong  spurs  which  project 
forward  and  are  bent  upward  sharply  at  right  angles  to  engage  the  labio- 
occlusal  edges  of  the  upper  incisors,  as  shown  on  one  incisor  in  Fig.  728. 
The  stability  of  the  teeth  used  as  anchorage  should  be  reinforced  by  a 
section  of  the  G  wire  soldered  across  the  lingual  surface  of  their  bands 
and  made  to  bear  against  the  adjoining  lateral  incisors. 

Sometimes  it  may  be  desirable  to  place  the  bands  upon  the  canines 

Fig.  728.  Fig.  729. 


E.  H.  A. 


instead  of  upon  the  incisors,  and  connect  them  by  a  bar  of  metal  con- 
taining the  retaining  spurs.  Fig.  729. 

If  the  reader  will  study  this  device  he  will  observe  that  not  only  is 
normal  closure  of  the  jaw  compulsory,  but  the  incisors  are  kept  com- 
pressed in  their  sockets  and  prevented  from  moving  labially  as  well. 
Still  another  advantage  of  no  small  importance  is  gained  in  preventing 
the  lower  lip  from  being  drawn  against  the  lingual  surfaces  of  the  upper 
incisors,  a  habit  which  seems  to  be  almost  universal  in  these  cases,  and 
difficult  but  most  necessary  to  overcome. 

Treatment. 

Ag-e  Appropriate  for  Treatment. — While  the  age  at  which  the  cor- 
rection of  mal-occlusion  may  be  accomplished  extends  over  quite  a  wide 
range  of  years,  the  writer  is  more  and  more  impressed  with  the  advan- 
tages of  beginning  treatment  early,  or  just  as  soon  as  the  irregularities 
are  manifest  and  the  teeth  have  emerged  from  the  gums  sufficiently  to 
admit  of  making  suitable  attachments.  Then  nature  is  putting  forth 
her  best  effiarts ;  then  growth  and .  repair  are  most  rapid  and  the  sur- 
rounding tissues  most  yielding ;  then  slight  force  is  sufficient  to  gently 
direct  each  erupting  tooth  into  its  correct  relation  with  the  line  of 
occlusion. 

Unless  some  unusual  physical  condition  of  the  patient  exists,  it  is 
unquestionably  a  serious  mistake,  without  the  least  argument  in  its  favor, 
to  defer  the  operation  unlil  all  the  teeth  shall  have  erupted,  as  is  still 
so  often  advocated.     By  this  time  the  whole  dental  apparatus  will  have 


7H4  ORTHODONTIA. 

become  greatly  complicated,  the  teeth  fixed  in  their  malpositions,  the 
facial  lines  badly  marred,  and  the  lips  and  muscles  modified  to  work  in 
harmony  with  the  complicated  mal-ooelusion,  all  of  which  in  most  cases 
might  have  been  easily  avoided  had  the  operation  been  begun  when 
mal-occlusion  was  first  manifest. 

There  is  another  reason,  it  would  seem,  in  favor  of  early  treatment. 
We  have  already  seen,  in  the  study  of  the  alveolar  process  and  periden- 
tal membrane,  that  in  young  patients  the  sockets  of  the  teeth  are  large 
and  the  intervening  septa  of  bone  often  lacking  to  a  considerable  extent, 
nature  seemingly  waiting  until  the  positions  of  the  teeth  shall  be  deter- 
mined before  completing  her  work.  Now,  if  the  teeth  be  moved  at  this 
time  into  correct  position,  the  normal  deposition  of  bone  and  develop- 
ment of  the  socket  about  the  root  of  the  tooth  will  follow ;  while  if 
movement  be  delayed  until  the  complete  development  of  the  alveolar 
process,  extensive  absorption  will  be  necessitated,  as  well  as  greater  force 
in  effecting  the  movement,  and  the  redepositiou  of  bone  may  be  less 
stable  in  quality  or  even  lacking  entirely,  as  we  believe,  in  some 
instances. 

AVhile  the  period  for  the  treatment  of  mal-occlusion  may  extend  to 
maturity  or,  in  favorable  eases,  much  later,  we  think  it  may  be  regarded 
as  a  law  that  in  proportion  to  the  age  of  the  patient  are  the  time  re- 
quired for  treatment,  the  obstacles  to  be  overcome,  the  inconvenience, 
the  period  of  retention,  and  uncertainty  as  to  prognosis  increased. 

We  have  pointed  out  elsewdiere  the  nselessness  of  delaying  treat- 
ment with  the  hope  that  nature  will  correct  the  deformity  ;  that,  on  the 
contrary,  it  is  practically  a  law  that  mal-occlusion  is  perniciously  pro- 
gressive. 

The  writer  is  convinced  that  with  the  eruption  and  locking  of  the 
first  permanent  molars  begins  our  greatest  opportunity  for  the  treatment 
of  mal-occlusion. 

In  the  treatment  of  all  cases  of  mal-occlusion  our  efforts  should  be 
directed  toward  the  accomplishment  of  two  main  objects : 

First,  the  correction  of  mal-occlusion  and  the  establishment  of  har- 
mony in  the  sizes  and  relations  of  the  dental  arches ;  and,  second,  the 
improvement  of  the  facial  lines. 

Treatment  of  Cases — Class  I. 

As  we  have  already  noted  in  the  classification  of  mal-occlusion,  the 
number  of  cases  belonging  to  this  class  is  the  greatest  and  comprises  by 
far  the  largest  variety,  the  distinguishing  characteristic  of  the  class 
being  relative  normal  relations  of  the  jaws,  with  molars  in  correct 
relation  mesio-distally,  although  one  or  more  may  be  in  buccal  or 
lingual  occlusion.     The  raalposed  teeth  are  usually,  however,  confined 


TREATMENT. 


785 


to  those  anterior  to  the  molars^  and  more  commonly  to  the  incisors  and 
canines,  the  dental  arches  being  smaller  than  normal  and  the  teeth 
crowded  and  overlapping.  Both  arches  are  usually  involved, 
and  sometimes  quite  similarly. 

As  the  mesio-distal  relations  of  the  lateral  halves  of 
the  dental  arches  are  normal  in  this  class,  it  must  follow 
that,  if  the  teeth  of  each  arch  be  moved  into  harmony  with 
their  lines  of  occlusion,  both  arches  must  then  be  in  perfect 
harmony  as  to  size  and  the  teeth  be  in  normal  occlusion. 

Fig.  730  represents  a  very  common  form  of  mal-occlusion 
belonging  to  this  class.  It  will  be  seen  that  the  mesial  and 
distal  inclined  planes  of  the  mesio-buccal  cusp  of  the  upper 
first  molar  on  the  right  is  received  between  the  inclines  of 
the  mesio-  and  disto-buccal  cusps  of  the  lower  first  molar,  or  that  the 
relations  of  the  first  molars  are  normal.  (The  molars  of  the  opposite 
side  were  also  in  normal  relation.)  The  arches  are  diminished  in  size 
and  the  teeth,  especially  the  incisors,  occupy  positions  lingual  to  the 
normal  line  of  occlusion. 

What  is  then  clearly  indicated  is  that  the  arches  be  enlarged  and 
each  tooth   moved   into  its  correct  position  in  the  line  of  occlusion,  as 


E.  H.  A. 


Fig.  730. 


Iff!"'   1:  ■iiii'VrTiraiT,- 


shown  in  the  case  when  completed  (Fig.  731),  and  in  the  plan  of  treat- 
ment of  any  case,  as  has  been  said,  it  makes  but  little  diflFerence  what 
positions  the  malposed  teeth  may  occupy,  they  are  always  subject  to  one 
general  requirement.  In  the  completed  case,  as  shown  in  the  engrav- 
ing, it  will  be  seen  that  each  tooth  has  been  placed  in  harmony  with  its 
line  of  occlusion,  and  is,  therefore,  now  in  best  position  to  support  and 
be  supported  by  all  the  remaining  teeth,  as  well  as  to  be  in  best  harmony 
with  the  muscles  and  normal  facial  lines. 

Fig.  732  shows  one  of  the  most  complicated  types  of  cases  belong- 
50 


(86 


ORTHODONTIA. 


ing  to  this  class.  liotli  lateral  halves  of  the  iipjxT  arch  are  in  lingual 
occlusion,  thus  greatly  encroaching  upon  its  incisive  region  and  forcing 
the  laterals  into  luarketl  torso-lingual  occlusion,  and  the  centrals  into 
torso-labial  occlusion. 

Fig.  T.-^I. 


The  result  of  the  nial-relation  of  the  buccal  cusps  of  the  upper  molars 
and  premolars  with  the  lingual  cusps  of  their  opposing  teeth,  as  shown 
by  the  dotted  lines  in  Fig.  733,  is  to  force  the  apices  of  the  roots  of  the 


Fig. 


lower  molars  and  premolars  farther  and  farther  bnccally,  and  of  the 
upper  molars  and  premolars  farther  and  farther  lingually,  with  the 
result  of  abnormally  M'idening  the  lower  jaw  and  narrowing  the  upper, 
and  giving  a  peculiar  bagginess  to  the  lower  part  of  the  face. 


TREATMENT. 


787 


This  condition  of  mal-occlusion  is  always  progressive,  and  dates  from 
the  eruption  and  abnormal  locking  of  the  first  permanent  molars.  Had 
these  teeth  received  but  a  few  hours  intelligent  attention  at  the  right 
time,  thus  allowing  them  to  take  their  normal  relations,  instead  of  per- 
mitting them  to  take  abnormal  relations,  doubtless  the  mal-occlusion 


Fig 


would  have  ended  here,  and  the  eruption  of  the  teeth  and  development 
of  the  alveolar  process  subsequent  to  this  would  have  been  along  normal 
lines.     Yet  dentists  will  persist  in  advising  parents  to  defer  treatment 
of  their  children's  mal-occlusion  until  all  of  the  teeth  have  erupted. 
The  line  of  treatment  was  toward  the  ideal,  the  widening  of  the 


upper  arch,  the  correcting  of  the  malpositions  of  the  incisors,  and  the 
narrowing  of  the  lower  arch. 

Fig.  734  shows  the  upper  arch  being  widened  by  means  of  the  ex- 
pansion arch,  adjusted  in  the  usual  way,  and  reinforced  by  one  of  the 


788 


ORTHODONTIA. 


spring  levers  L,  all  as  shown  and  (Uscriixd  in  tin-  section  on  Adjust- 
ment and  Operation  of  Appliances.  The  incisors  were  moved  forward 
en  inofiiic  and  rotated  by  means  of  spurred  bands,  ligatures,  etc.,  after 
the  usual  method. 

The  narrowing  of  the  lower  arch  was  effected  by  means  of  a  device  ^ 


manufactured  for  the  occasion  and  shown  in  Fig.  733 ;  but  the  recent 
practice  of  the  writer  is  to  narrow  the  dental  arches  in  such  cases  with 
the  expansion  arch  (ribbed),  it  having  been  found  that  it  contains  ample 
force  for  this  purpose. 


Fig.  736. 


In  making  use  of  the  ribbed  arch,  as  above,  it  is  only  necessary  to 
compress  its  sides  so  that  they  are  perhaps  two-thirds  the  width  of  the 
dental  arch  to  be  narrowed,  and  insert  the  ends  in  the  sheaths  of  the  D 

'  This  device  is  fully  described  in  the  sixth  edition  of  the  writer's  Mcjrocdvsum  of  the 
Teeth  and  Fractures  of  the  MoxHUe, 


TREATMENT.  789 

bands,  as  usual,  care  being  taken  to  retain  all  of  the  spring  in  the  lin- 
gual direction  possible.  The  arch  is  prevented  from  springing  forward 
by  being  secured  to  the  incisors  by  one  or  more  ligatures.  Although  its 
action  is  slow,  requiring  several  weeks  in  a  patient  sixteen  years  of  age, 
the  writer  has  found  its  use  most  satisfactory. 

Fig.  735  shows  the  upper  arch  completed  and  the  retaining  devices 

Fig.  737. 


in  position,  while  Fig.  736  shows  both  arches  completed  and  the  teeth 
in  occlusion.  The  lingual  tendency  of  the  upper  incisors  and  the  torso- 
infra-occlusal  tendencies  of  the  upper  canines,  as  well  as  the  lingual 
tendency  of  the  molars  and  premolars,  were  resisted  by  double  bands 
connected  by  a  section  of  the  wire  G  and  a  vulcanite  plate,  as  illus- 
trated.    The  bands  upon  the  cuspids  are  also  shown  in  Fig.  736. 

Fig.  738. 


The  model  illustrated  in  Fig.  737  represents  a  case  where  one  only 
of  the  lateral  halves  of  the  upper  arch  was  in  lingual  occlusion,  while 
the  lateral  incisors  were  in  marked  torso-lingual  occlusion.  The  patient 
was  a  child  eight  years  old,  the  deciduous  molars  and  canines  being 
still  in  position. 

The  plan  of  treatment  clearly  indicated  was  widening  the  arch  by 


790 


ORTHODONTIA. 


movement  buccally  of  the  affected  side  only,  with  labial  movement  of 
the  centrals  and  torso-labial  movement  of  laterals.  Fig.  738  shows  a 
view  of  this  arch  from  the  occlusal  aspect,  with  the  appliances  for 
accomplishing  these  movements  of  the  teeth  in  position. 


Fi<;.  7:W. 


It  will  be  seen  that  all  of  the  teeth  on  the  left  side  are  used  as 
anchorage,  and  that  their  coml)ined  resistance  is  concentrated  through  the 
force  distributed  by  the  external  and  internal  arches  upon  the  left  first 


Fig.  740. 


permanent  molar.  But  a  few  days  were  necessary  to  move  this  tooth 
into  correct  position.  A  wire  ligature  was  then  made  to  encircle  the 
second  deciduous  molar  and  the  expansion  arch,  thus  practically  trans- 
ferring the  force  to  this  tooth.     Later,  the  first  deciduous  molar  was 


TREATMENT. 


791 


moved  out  in  the  same  way.  The  object  of  moving  the  teeth  one  at  a 
time  was  to  avoid  overtaxing  the  anchorage  derived  from  the  opposite 
side  of  the  arch.  Had  the  effort  been  made  to  move  all  at  the  same 
time,  it  is  probable  that  the  normal  side  would  have  been  displaced 
more  rapidly  than  the  abnormal,  on  account  of  the  increased  resistance 
offered  by  the  inlocking  of  the  inclined  planes  of  the  cusps  of  the 
molars  on  the  abnormal  side. 

Fig.  741. 


While  the  appliances  were  acting  upon  the  lateral  half  of  the  arch, 
the  lateral  incisors  were  carried  forward  and  rotated  by  bands,  spurs, 
and  ligatures,  with  notches  on  the  ribbed  expansion  arch  to  prevent 
slipping,  further  assisted  by  the  tightening  of  the  nuts  on  the  expansion 
arch,  as  in  the  case  last  described. 

By  studying  the  positions  of  the  teeth  in  the  upper  arch,  it  will  be 
seen  that  their  tendencies  were  similar  to  those  in  the  last  case,  and 


792  ORTHODONTIA. 

that  tliey  were  overcome  in  a  .similar  manner  and  by  tlie  same  combina- 
tions of  bands  and  spurs.  The  widened  arch  was  retained  bv  the  vul- 
canite plate  (Fi^.  72.3). 

The  mesial,  torsional,  and  lingual  tendencies  of  the  right  lateral  and 
the  lingual  tendencies  of  the  otiier  incisors  were  resisted  by  bands  upon 
the  laterals  connected  by  a  piece  of  G  wire  soldered  to  their  lingual 
surfaces. 

This  type  of  mal-ocelusion  is  more  c-ommon  among  children  than 
seems  to  be  commonly  supposed,  and  it  is  important  that  they  receive 
early  attention,  for  if  allowed  to  progress  the  mouth  must  inevitably 
develop  asymmetrically — the  jaw  be  shifted  to  one  side,  giving  a  peculiar 
twisted  appearance  to  the  mouth. 

Figs.  739,  740,  and  741  illustrate  a  case  in  its  labial,  buccal,  and 
occlusal  aspects,  and  from  the  position  of  the  canin(^s  and  the  mesio- 
buccal  cusps  of  the  upper  first  molars,  it  will  be  readily  recognized  as  a 
typical  case  belonging  to  the  first  class. 

It  will  be  seen  that  the  arches  are  much  shortened  and  reduced  from 
the  normal  size,  with  marked  lingual  positions  of  all  the  incisors,  the 
left  upper  lateral  being  in  contact  with  the  first  premolar,  causing  almost 
complete  labial  displacement  of  the  left  canine,  while  at  least  one-half 
of  the  space  necessary  for  the  right  canine  is  occupied  by  the  right 
lateral,  the  influence  of  the  lips  effectually  maintaining  the  diminished 
size  of  the  arches  and  the  mal-occlusion. 

The  effect,  as  might  be  supposed,  was  very  noticeable  in  the  facial 
lines  of  the  patient,  as  shown  in  Fig.  616,  producing,  as  we  have  seen, 
a  pinched  and  flattened  appearance  about  the  mouth. 

As  so  much  space  would  be  required  for  admission  of  the  upper 
canines  into  the  line  of  occlusion,  the  extraction  of  one  first  premolar 
in  this  arch  might  at  first  suggest  itself,  but  the  development  of  the 
alveolar  process  and  demands  of  the  facial  lines  were  such  as  would 
have  made  such  a  course  inexcusable.  What  was  clearly  indicated  was 
the  restoration  of  all  the  teeth  to  normal  occlusion  by  slightly  widening 
both  arches,  moving  labially  all  the  incisors  into  line,  and  performing 
elevation,  rotation,  and  a  slight  lingual  movement  of  the  canines. 

Fig.  742  shows  these  various  movements  being  accomplished  in  both 
arches  simultaneously  by  means  of  ribbed  expansion  arches,'  D  bands, 
spurred  bands,  wire  ligatures,  etc.,  adjusted  and  operated  as  described 
in  the  section  on  Adjustment  and  Operation  of  Appliances. 

The  anchorage  was  effected  by  means  of  D  bands  placed  upon  the 

'  Several  of  the  cuts  Hhowing  the  expansion  arch  were  made  before  the  invention  of 
the  ribbed  expansion  ar(;h,  therefore  soldered  spurs  on  the  plain  arch  to  prevent  the  slip- 
ping of  the  ligiitures  are  shown  instead  of  notches  in  tli«  ribbed  arch,  as  now  used,  but 
referred  to  in  the  text  as  though  the  notched  ribbed  arch  had  been  used. 


TREATMENT. 


793 


f5rst  molars  in  the  lower  arch,  while  in  the  upper  arch  a  D  band  upon 
the  first  molar  was  used  on  the  right  side  and  an  X  band  on  the  first 
premolar  on  the  left  side,  it  being  found  necessary  after  a  few  days  of 
treatment  to  transfer  the  anchorage  from  the  left  first  molar  to  this 
tooth,  as  the  molar  showed  displacement  distally  in  resisting  the  strain 
of  the  labial  movement  of  the  incisors.  It  is  not  surprising  that  the 
first  molar  did  show  weakness  of  anchorage  and  move  distally  in  this 
case,  as  it  may  in  all  cases  at  this  age,  for  the  reason  that  the  second 
molar  gives  it  no  support,  it  being  still  unerupted  and  lying  in  a  large 
open  crypt  into  which  the  first  molar  may  quite  easily  be  moved.  It  is 
usually  well  in  such  cases  to  reinforce  the  molar,  which  can  easily  be 

Fig.  742. 


done  by  enlisting  the  support  of  one  or  both  of  the  premolars  by  means 
of  a  wire  ligature  made  to  encircle  them,  and  the  wire  ligature  pre- 
vented from  sliding  beneath  the  gum  by  being  made  to  rest  on  some 
portion  of  the  D  band. 

It  will  be  noticed  that  there  are  two  ligatures  upon  the  left  lateral 
incisor  (upper).  One  is  a  plain  ligature,  as  in  A,  Fig.  684,  for  effecting 
the  labial  movement ;  the  second,  as  in  B,  Fig.  684,  encircles  the  arch 
and  a  spur  soldered  low  down  upon  the  lingual  surface  of  the  band 
upon  the  lateral.  The  office  of  this  ligature  was  partly  to  assist  in 
carrying  the  incisor  forward,  but  principally  to  effect  its  rotation,  A 
notch  in  the  rib  of  the  expansion  arch  prevented  this  ligature  from  slid- 


7IU  ORTHODONTIA. 

ing  forward  and  diivcti-d  the  movement  of  the  tooth  laterally,  the  arch 
being  so  bent  that  in  shape  and  spring  it  bore  toward  the  loft  and  favored 
this  movement,  assisted  reciproeally  by  the  band,  spur,  and  ligatures 
npon  the  right  lateral.  The  reason  for  the  spurs  being  placed  well 
toward  the  gum,  as  is  important  in  all  such  eases,  is  that  it  resists  the 
tendency  of  the  arch  to  slide  toward  the  ocelusttl  edges  of  the  teeth.  This 
tendency  is  further  opposed  by  the  crossing  of  the  ligature  near  the  spur. 

The  right  upper  lateral  is  also  encircled  by  a  ligature,  Mhich  is  pre- 
vented from  sliding  off  the  tooth  by  the  band. 

The  form  of  the  expansion  arch  was  occasionally  modified  bv  bend- 
ing to  meet  the  requirements  of  the  moving  teeth  and  prevent  bunching. 

Not  until  the  incisors  had  been  moved  labially  sufficiently  for  the 
full  admission  of  the  canines  into  the  line  of  occlusion  was  any  effort 
made  toward  elevating  them  in  their  sockets.  This  was  also  effected 
by  enlisting  the  spring  of  the  expansion  arch.  Wire  ligatures  were 
carefully  worked  beneath  the  gum  and  above  the  gingival  ridges  of  the 
canines  and  given  one  full  twist  on  the  labial  surface,  followed  by  a 
final  one-fourth  twist  from  the  grasp  of  the  pliers.  One  of  the  long 
ends  was  then  made  to  encircle  the  arch,  a  second  twist  given,  and  the 
ends  clipped  down  to  the  usual  length.  This  ])eriod  in  the  treatment  is 
shown  in  the  engraving  (Fig.  742),  made  from  a  study  model  taken  in 
wax  with  the  appliances  in  position. 

Tension  on  the  canines  by  the  spring  of  the  expansion  arch  was 
oceasionallv  intensified  by  an  additional  twist  in  the  ligatures,  fir.^t 
always  pressing  upward  upon  the  arch  with  the  finger  in  order  to 
relieve  the  strain  upon  the  ligature  while  twisting.  The  writer  tio 
longer  believes  in  forcing  the  eruption  of  the  canines  by  mechanical 
means  at  this  age.  A  wider  experience  has  led  him  to  adopt  the  con- 
servative method — namely,  to  provide  space  and  allow  nature  to  do  the 
erupting  simultaneously  with  the  development  of  the  previously  arrested 
intermaxillary  bones.  Better  results  are  gained,  as  well  as  the  saving 
of  time  both  of  patient  and  orthodontist. 

The  movement  of  rotation  being  the  most  difficult,  it  was  delayed 
until  the  teeth  were  fully  erupted  to  the  line  of  occlusion,  when  the 
spurred  band,  wire  ligature,  and  wedges  of  rubber  were  ap])Ho(l  after  the 
usual  manner  for  accomplishing  the  movement,  and  soon  brought  ai)out 
the  desired  results. 

Owing  to  the  lingual  inclination  of  the  crowns  of  the  lower  incisors 
no  bands  were  necessarv,  the  ligatures  simply  encircling  the  expansion 
arch  and  crowns  of  the  teeth.  The  lateral  pressure  from  the  teeth  pre- 
vented the  ligatures  from  sliding  off.  It  will  be  noted  that  a  notch  in 
the  ribbed  arch  directed  the  movement  of  the  canine  laterally  as  well  as 
labially. 


TREATMENT. 


795 


The  slight  necessary  rotation  of  the  left  second  premolar  was  accom- 
plished by  bands,  spurs,  ligatures,  and  rubber  wedges,  as  already 
described,  as  soon  as  the  anterior  teeth  had  been  moved  into  correct 
position  to  reduce  the  crowding  and  permit  it  to  turn. 

The  teeth  of  the  upper  arch  were  retained  in  their  new  positions  by 

Fig.  743. 


a  section  of  wire  G  soldered  to  the  mesio-lingual  angles  of  bands  on  the 
canines  and  made  to  bear  against  the  lingual  surfaces  of  the  intervening 
incisors,  as  in  Figs.  714  and  752. 

The  lateral  tendency  of  the  lower  canine  and  the  lingual  tendency 
of  the  incisors  were  antagonized  by  a  similar  device,  and  the  canine  was 

Fig.  744. 


retained  by  a  band  and  spur,  the  end  bearing  upon  the  lingual  surface 
of  the  first  premolar,  as  in  Fig.  718. 

Fig.  743  shows  the  upper  model  of  the  case  soon  after  its  comple- 
tion, and  Fig.  744  nearly  two  years  later,  and  it  is  interesting  to  note, 
by  comparing  the   two  cuts,  what  a  marked  change  has  occurred  in  the 


'90 


ORTHODONTIA. 


alvcohir  process  in  the  region  of  the  incisors.  Xatiirc,  unaided,  lias 
sliifted  the  roots  of  thi'se  teeth  to  ch)sely  appnixiniate  their  ideal  posi- 
tions. 

Fig.  617   represents   the  face   of  the   patient   at   tliis   time,  and   the 
improvement  in  the  facial  contour  is  very  noticeable  and  gratifying. 

Fig.  745. 


Fig.  745  shows  another  case  similar  to  the  one  just  described.  The 
main  peculiarities  are  almost  identical,  the  difference  really  constituting 
only  one  of  the  ever-varying  combinations  in  the  malpositions  taken  by 
the  incisors,  with  the  same  general  re(piiremcnts. 


Yu 


Fig.  74G  shows  the  upper  model  from  the  occlusal  aspect,  with  the 
appliances  in  position  at  the  beginning  of  treatment.  It  will  be  noted 
that  each  arch  is  greatly  diminished  in  size,  and  that  there  is  marked 
arrest  in   the  development  of  the  alveolar  process  in  the  region  of  the 


TREATMENT. 


797 


incisors.  These  teeth  were  moved  labially  in  the  usual  way,  and  similar 
to  that  in  the  case  last  described.  The  same  plan  was  also  followed  in 
the  correction  of  the  positions  of  the  lower  teeth. 

Fig.  747  shows  the  occlusion  of  the  case  after  correction,  with  retain- 
ing bands  upon  the  canines.  All  four  canines  were  banded  and  con- 
nected by  sections  of  G  wire,  as  in  Fig.  735. 

Fig.  747. 


Figs.  748  and  633  represent  the  upper  model  of  the  case  from  the 
occlusal  and  labial  aspects  three  years  after  the  removal  of  all  appliances. 
By  comparing  these  with  Figs.  632  and  747  (which  also  represent  the 
same  case),  it  will  be  noted  what  a  remarkable  change  has  taken  place  in 


Fin.  748. 


the  development  of  the  alveolar  process  in  the  region  of  the  incisors. 
There  has  also  been  a  shifting  labially  of  the  apices  of  the  roots  of  the 
incisors  until  these  teeth  occupy  ideal  positions  and  inclinations,  with  an 
equally  gratifying  change  in  the  contour  of  the  face. 


7!».s 


ORTHODONTIA. 


Before  Icaviiii;  this  case  anotlicr  point  of  interest  should  he  mentioned. 
It  will  he  seen  in  Fio-.  747  that  the  premohirs  are  in  slight  infra-oeeju- 
sion,  bnt  as  they  are  ])erfeetly  plaecd  in  other  respects,  the  writer  deems 
it  good  practice  in  all  similar  cases  to  allow  any  slight  shortness  of  tiie 
teeth  to  be  adjusted  by  nature,  rather  than  to  prolong  treatment  beyond 
the  period  necessary  to  the  accomplishment  of  the  essential  ])rinciples  in 
the  establishment  of  occlusion,  knowing  full  well  that  this  will  soon  be 
effected,  and  that  the  inclines  of  the  cusps  will  certainly  guide  them  into 
correct  positions. 

In  Fig.  750  is  shoMu  another  case  belonging  to  this  class  which  is 


V\u.  74ii. 


^Blr^ 

^Mu^mT^ 

11 

^^^<<^ 

^■^K^  >-■£•. 

J 

K^' 

^H&  ^^. 

.,^^_«»r7'                 M 

represented  from  the  labial  aspect,  wiiile  Fig.  750  shows  the  occlusal 
surface  of  the  teeth  of  both  arches. 

From  the  positions  of  the  mesio-buccal  cusps  of  the  upper  first  molars 
relative  to  the  lower  first  molars,  the  case  is  readily  diagnosed  as  belong- 
ing to  the  class  under  discussion. 

The  patient  was  a  lad  aged  thirteen.  The  strongly  developed 
canines  are  erupting  and  have  forced  the  lateral  incisors  liugually  and 
the  centrals  into  torso-occlusion,  while  all  the  lower  incisors,  though 
quite  even,  occupy  positions  lingual  to  normal,  and  the  canines  are  in 
torso-distal  occlusion. 

Fig.  751  illustrates  a  study  model,  made  with  the  appliances  in  posi- 
tion, and  shows  the  upper  incisors  being  moved  labially  en  masse  by 
means  of  the  expansion  arch,  ligatures,  and  spurred  bands,  the  spur  and 


TREATMENT. 


799 


ligatures  acting  upon  the  right  central  to  effect  the  movement  of  rotation 
at  the  same  time.  It  will  be  noted  that  the  deciduous  second  molar  has 
been  removed  and  the  anchor-band  X  placed  upon  the  first  premolar, 
not  in  order  to  secure  greater  anchorage  than  that  which  would  be 
offered  by  the  first  permanent  molar,  but  to  shift  the  tooth  distally 
somewhat  in  order  to  gain  much-needed  space  for  the  canine.  The 
loosened  temporary  molar  was  not  removed  and  change  in  the  anchorage 
made  until  sufficient  anchorage  from  the  firm  permanent  molar  with  a 
D  band  had  been  utilized  to  move  the  incisors  forward  to  nearly  their 
correct  positions. 

The  arch  was  bent  to  accentuate  the  labio-buccal  movement  of  the  left 

Fig.  750. 


lateral  incisor,  the  force  being  reciprocated   from  the  first  premolar  on 
the  left  through  its  attachment  by  the  ligature,  as  shown. 

The  disto-torso-occlusal  position  of  the  lower  canines  shown  in  this 
case  is  the  malposition  most  often  assumed  by  these  teeth,  not  only  in 
this,  but  also  in  other  classes  of  mal-ocelusion,  and  as  their  movement  is 
unquestionably  one  of  the  most  difficult  to  perform  they  are  too  often 
left  undisturbed.  But  as  we  now  know  that  there  must  be  complete 
harmony  in  the  sizes  of  the  arches  in  order  to  insure  permanency  of  cor- 
rected occlusion,  and  as  we  also  know  that  the  lower  arch  is  the  pattern 
for  controlling  the  size  and  form  of  the  upper  arch,  how  important  does 
it  appear  that  these  teeth  shall  be  moved  forward  and  turned  in  their 
sockets  in  all  cases,  that  they  may  do  their  part  in  establishing  the  full 


800 


OliTlIoDuSTIA. 


size  of"  the  arch.  Tlic  canines  then,  as  tlicy  should,  not  only  hccome  as 
keystones  in  the  hiteral  halves  of  their  own  arch,  but  in  ii  degree  in 
those  of  the  upper  arch,  through  occlusal  influence.  Otherwise  \ve  must 
expect  a  corresponding  iliniinution  in  the  size  of  the  upper  arch,  with  a 
bunching  of  the  teeth,  through  the  influence  of  the  lips. 

It  mu.st  be  remembered  that  space  for  their  accommodation  must 
always  be  provided  before  rotation  will  be  j)ossible.  They  must,  there- 
fore, be  carried  forward  until  their  distal  angles  .shall  be  free  from  inlock 
with  the  mesial  angles  of  the  first  premolars.  To  insure  this  in  this 
case,  notches  were  made  in  the  ribbed  arch  to  prevent  the  ligatures  from 
slipping  as  the  nuts  were  tightened,  as  in   Fig.  687.     In  the.se  cases  the 


Fk;.  7')1. 


writer  has  often  used  with  advantage  a  double  ligature.  In  this  way  the 
most  stable  attachment  is  gained  and  a  power  exerted  equal  to  the 
direct  application  of  a  jack-.screw.  With  no  other  form  of  ligature 
would  it  be  possible  to  exert  pressure  upon  the  tooth  in  so  effective  a 
manner. 

After  the  canines  were  moved  forward  sufficiently  to  be  free  from  the 
premolars,  their  rotation  was  expeditiously  effected  by  occasional  renewal 
of  ligjitnres  in  the  usual  manner,  the  spring  of  the  arch  being  made  con- 
stant by  wedges  of  rubber  stretched  between  it  and  the  tooth  bands,  as 
properly  shown  in  the  engraving. 

The  writer  Ix'lieves  this  to  be  the   most  powerful   and    practicable 


TREATMENT. 


801 


means  known  for  performing  these  oft-needed  movements.  If  analyzed, 
it  will  be  seen  that  the  appliance  is  only  a  series  of  levers,  made  to  act 
in  the  most  eflPective  manner  ou  pure  mechanical  principles,  combining 
reciprocal  and  simple  anchorage,  while  permitting  the  most  perfect  con- 
trol over  the  directions  of  movement. 

Fig.  752  shows  the  teeth  after  they  have  been  moved  into  harmony 
with  the  line  of  occlusion,  the  retaining  devices  in  position. 

By  studying  the  original  positions  of  the  teeth  in  Figs.  749  and  750, 
together  with  their  corrected  positions  in  this  figure,  it  will  be  seen  that 
the  connection  of  the  upper  canines  by  bands  and  a  section  of  G  wire, 
as  in  Fig.  714,  not  only  resists  their  torso-labial  tendency,  but  that  their 

Fig.  752. 


infra-occlusal  tendency  is  also  resisted  by  the  resting  of  the  wire  upon 
the  linguo-gingiv'al  ridges  of  the  laterals,  whose  lingual  tendencies  are 
in  turn  resisted  by  the  wire,  while  their  mesial  tendencies  are  resisted 
by  the  centrals.  At  the  same  time  the  laterals  exercise  resistance  to  the 
rotation  of  the  centrals  by  contact  with  their  disto-lingual  angles,  while 
the  mesial  angles  of  the  centrals  are  prevented  from  moving  labially  by 
the  tension  of  the  fibres  of  the  peridental  membrane,  care  having  been 
exercised  to  preserve  this  tension  by  exerting  force  for  their  proper  rota- 
tion only  on  their  disto-lingual  angles.  Had  they  been  moved  labially 
before  rotation,  there  would  have  been  mesial  disturbance  of  the  fibres 
instead  of  distal  disturbance  only,  necessitating  their  retention  by  two 

51 


802 


ORTHODONTIA. 

Fio.  753. 


Fig.  754. 


united  haiuL^^.     Much  may  often  be  gained  by  an   intelligent  use  of  the 
advantages  offered  by  the  peridental  membrane. 


TREATMENT. 


803 


The  lower  right  lateral  and  canine  M'ere  retained  each  by  a  single 
band  and  spur,  preventing  their  torso-distal  displacement.  Of  course, 
the  same  eflfect  would  have  resulted  from  the  bands  being  soldered 
together,  with  one  spur  from  the  canine  only  bearing  against  the  buccal 
surface  of  the  first  premolar,  but  the  difficulty  of  adjusting  both  bands 
at  the  same  time,  so  that  one  of  them  would  not  become  loosened  and 
cause  injury  to  the  enamel,  as  they  were  to  be  worn  in  this  case  for 
nearly  two  years,  made  the  plan  objectionable. 

There  is  another  decided  advantage  in  the  use  of  spurs  in  all  such 
cases,  in  that  the  finer  adjustment  of  the  teeth  may  be  easily  eifected 
after  the  application  of  the  retaining  devices  by,  in  each  instance,  stretch- 
ing a  piece  of  rubber  between  the  anchor  tooth  arid  spur,  to  create  a 


Fig.  755. 

■■■Pl 

^W^^^MBj 

I 

■ 

^^^^^^P   ■ 

1 

^H 

_  _,*»»>  • . 

1 

t«^ 

-^^1 

r-       ' 

(ir- 

"'**•'       i 

^ 

J 

y4^  ^.,>.~.ip--/^'<«l 

H 

'"^^    1 

■  *  ^^S 

Sr-i 

1 

K. 

K  I 

1 

^K 

^ 

'  ' :■■•  - 

^^ 

i 

1 

leverage,  and  on  its  subsequent  removal  bending  back  the  spur  to  hold 
the  position.  Figs.  753  and  754  represent  the  occlusion  and  facial  lines 
of  the  patient  three  years  after  treatment. 

Attention  is  again  called  to  the  development  to  normal  contour  of 
the  alveolar  process  in  the  region  of  the  apices  of  the  upper  incisors 
which  has  followed  the  establishment  of  normal  occlusion  and  function 
of  the  teeth.  It  will  also  be  noted  that  the  retention  of  all  of  the  teeth 
has  not  caused  undue  prominence  of  the  lips,  which  are  seen  to  be  in 
harmony  with  the  other  lines  of  the  face,  but  that  it  is  a  far  finer  result 
than  could  possibly  have  followed  the  sacrifice  of  one  or  two  teeth  from 
each  arch  to  gain  space. 

Figs.  755  and  758  represent  the  mal-occlusion  of  another  case — that 
of  a  boy  aged  eleven  years — and  Figs.  757  and  758  show  the  teeth  from 


804 


ORTHODONTIA. 


the    occlusal    aspect.     The   permanent   incisors   and    first   molars   have 
erupted.     The  lower  right  lateral   incisor  early  took  a  lingual   position 


Fi(. 


and  the  pressure  of  the  lips  acting  externally  to  the  arch  soon  closed  the 
space  between  the  central  incisor  and  the  deciduous  canine,  thereby 
diminishing  the  size  of  the  arch  to  the  extent  of  one  tooth.     The  press- 


Fi.,.  707. 


ure  of  the  muscles  of  the  lips  and  cheeks  gradually  molded  the  upper 
arch  to  conform  to  the  diminished  size  of  the  lower — only  an  accentuated 


TREATMENT. 


805 


condition  of  that  shown  in  Fig.  599 — and  all  similar  cases  allowed  to 
progress. 

It  will  be  seen  that  the  molars  have  locked  normally.  There  is, 
therefore,  the  normal  mesio-distal  relation  of  the  jaws  and  dental  arches, 
and  if  the  arches  be  slightly  enlarged  and  each  of  the  malposed  teeth 
be  placed  in  harmony  with  the  line  of  occlusion,  according  to  our  law  in 
the  treatment  of  all  cases,  there  will  then  be  harmony  between  the  in- 
clined planes  of  occlusion.  It  would  at  first  appear  that  there  is  not 
sufficient  room  to  accommodate  all  the  teeth,  and,  indeed,  extraction  was 
freely  advised  by  several  dentists,  yet  that  there  was  ample  room  for  all 
the  teeth  we  shall  see. 

Again,  by  studying  the  profile  of  the  young  man's  face  (Fig.  618),  it 
would  seem  that  to  apply  our  law  in  this  case  would  be  to  exaggerate  to 


Fig.  758. 


unsightliness  the  protrusion  of  the  lips.  But  this  is  readily  understood 
to  be  a  delusion,  after  studying  the  remarks  relating  to  this  same  case  on 
page  701. 

The  treatment  was  simple  and  easily  understood,  for  it  was  but  a 
repetition,  with  slight  modifications,  of  that  of  all  cases  so  far  de- 
scribed. 

The  four  upper  incisors  were  carefully  banded,  the  thin  band  material 
C  being  used  for  the  laterals,  and  the  thicker,  or  F,  upon  the  centrals. 
Spurs  of  G  wire  that  sloped  forward  and  downward  were  attached  at 
the  disto-lingual  angles  of  these  bands,  close  to  the  gingival  edge.  The 
right  lower  lateral  was  also  encircled  by  a  plain  band  having  a  spur 
attached  at  the  disto-linguo-gingival  margin. 


806 


ORTHODONTIA. 


D  bauds  were  carefully  fitted  to  both  upper  and  lower  first  molars, 
aft€r  the  manner  already  described.  The  expansion  arches  were  slipped 
into  position,  all  this  occupying  but  a  few  moments  at  each  of  three 
different  sittings,  so  that  the  patient  might  become  gmdually  accustomed 
to  the  wearing  of  the  appliances.  The  patient  was  then  dismissed  for  a 
week,  until  all  soreness  should  have  subsided  and  he  had  become  thor- 
oughly accustomed  to  the  appliances,  after  which  light  pressure  through 
plain  ligatures  made  to  encircle  expansion  arch  and  spurs  were  applied. 

Now,  by  studying  the  positions  of  the  teeth  from  the  occlusal  aspect 
in  Figs.  757  and  758,  it  will  be  seen  that  both  canines  in  both  upper 
and  lower  arches  must  be  moved  laterally  in  order  to  provide  space  for 
the  laterals  as  they  are  moved  into  their  correct  positions^  or  in  harmony 
with  their  proper  lines  of  occlusion  •  therefore  suitable  notches  were 
made  in  the  rib  of  the  expansion  arches  opposite  the  canines,  and  liga- 
tures made  to  operate  in  forcing  these  teeth  laterally.     At  the  same 


Fig.  7o9. 


time  the  permanent  centrals  and  laterals  were  being  rotated  into  their 
correct  positions. 

There  are  two  points  to  be  observed  in  the  shaping  of  the  expansion 
arches  for  this  case :  first,  that  they  shall  be  bent  so  as  to  avoid  exerting 
any  lingual  or  buccal  spring  upon  the  first  molars,  as  they  are  already 
in  correct  position  ;  second,  the  arches  should  be  bent  to  describe  a  some- 
what larger  circle  in  the  region  of  the  incisors  and  canines  than  that 
indicated  by  the  present  positions  of  these  teeth  ;  or,  in  other  words, 
they  must  be  wide  enough  in  this  region  to  permit  of  lateral  spring 
which  must  be  exerted  reciprocally  from  the  right  and  left  canines  and 
laterals,  as  well  as  centrals,  in  both  upper  and  lower  arches. 

The  widening  of  the  arch  in  the  region  of  the  deciduous  molars  in 
such  cases  is  often  good  practice,  yet  the  movement  of  the  deciduous 
molars  is  not  so  necessary  as  that  of  the  deciduous  canines,  for  the 
reason  that  the  permanent  canines  and  first  molars  must  determine  the 


TREATMENT. 


807 


width  as  well  as  the  length  of  the  arch^  and  the  positions  of  the  inter- 
mediate teeth,  or  the  premolars,  are  contingent  upon  the  positions  of  the 
two  former,  the  latter  being  molded  into  harmony  with  the  canine 
mesially  and  the  first  permanent  molar  distally  through  the  buccal  and 
lingual  action  of  the  muscles. 

It  may  be  well  to  again  caution  the  operator  of  little  experience  in 
regard  to  the  great  importance  of  so  placing  the  bands,  spurs,  arch,  and 
ligatures  that  all  will  act  with  the  greatest  efficiency.  A  loose  band  or 
ligature  is,  of  course,  useless,  and  its  wearing  but  the  waste  of  time.  A 
loose  arch,  or  one  operating  too  near  the  cutting  edges  of  the  teeth  for 
efficiency,  is  worse  than  useless. 

Fig.  759  shows  the  positions  of  the  teeth  from  the  occlusal  aspect 
after  the  necessary  movements  had  been  completed ;  Fig.  760  shows  the 
teeth  in  occlusion,  and  Fig.  619  shows  the  facial  lines. 


Fig.  760. 


The  expansion  arches  were  allowed  to  remain  in  position  for  a  couple 
of  weeks  in  order  that  all  soreness  might  subside  before  the  adjustment 
of  the  retaining  devices,  and  a  novel  method  of  temporary  retention 
was  effected — one  which  is  now  a  favorite  with  the  writer  whenever 
possible — namely,  the  making  use  of  the  bands  and  spurs  already  in 
position  upon  the  teeth,  in  connection  with  that  inestimable  boon  to  the 
orthodontist,  the  wire  ligatures,  they  being  wound  in  and  out  between 
the  teeth  and  made  to  engage  the  spurs  in  such  a  way  as  to  antagonize 
the  movement  of  the  teeth  in  the  direction  of  their  tendencies. 

In  this  case  a  loop  was  thrown  about  the  spur  on  the  disto-lingual 
angle  of  the  left  upper  lateral  incisor  and  both  ends  carried  forward  to 
the  central,  and  one  strand  passed  between  the  central  and  lateral  and 
made  to  engage  the  spur  upon  the  left  central,  brought  back  and  united 
by  a  firm  twist  with  the  other  strand  at  the  mesio-labial  angle  of  the 


SOS 


ORTHODONTIA. 


hitiTul.  AiuttluT  .strand  was  madi-  to  cii<fa<rc'  tlio  other  lateral  ami  cen- 
tral in  like  manner.  Finally,  another  strand  was  made  to  engage  the 
spur  of  the  left  central,  and  both  ends  brought  across  the  lal)ial  surfaces 
of  both  centrals,  and  one  of  tiie  ends,  made  to  engage  the  spur  upon  the 
right  central,  brought  back  and  firmly  united  with  the  other  end  by 
twisting,  all  as  illustrated  in  Fig.  705.  Thus  it  will  be  seen  how  effec- 
tively the  directions  of  the  tendencies  of  the  teeth  that  were  moved  were 
combated. 

To  the  close  observer  of  opportunities  there  are  great  possibilities  in 
this  method  of  temporary  retention.  The  chief  advantage  of  such  sim- 
ple yet  effectual  means  of  retention  is  the  avoiding  of  that  most  painful 
of  operations  in  orthodontia — the  placing  of  retaining  appliances  on  teeth 
where  the  tissues  have  been  disturbed  as  the  result  of  tooth  movement. 

After  several  weeks  of  temporary  retention,  the  teeth  were  perma- 

FiG.  761. 


tMA, 


nently  retained  according  to  methods  already  described  in  the  section 
on  Retention. 

Fig.  761  shows  a  case,  also  belonging  to  this  class,  in  which  there  is 
much  space  between  the  occlusal  edges  of  the  incisors,  the  result  of  the 
habit  of  holding  the  tongue  between  the  teeth.  The  cut  also  shows 
the  metliod  of  correcting  the  infra-occlusion  of  the  incisors  by  means  of 
the  expansion  arch.  The  middle  of  each  side  of  the  expansion  arch 
was  made  to  bear  against  a  spur  soldered  to  a  band  on  the  canine, 
which  acted  as  a  fulcrum,  the  centre  of  the  arch  being  sprung  over 
hook-like  spurs  projecting  from  the  labial  surfaces  of  bands  on  the 
incisors,  and  in  its  spring  thus  exerting  a  downward  force  upon  tliem. 
The  use  of  ligatures  instead  of  spurred  bands  for  the  incisors,  as  repre- 
sented in  Fig.  761,  is  now  preferred.  Either  of  the  arches  E  or  the 
arch  B  may  be  used. 

In  correcting  infra-occlusion  of  the  teeth  by  this  excellent  method, 
it  has  been  found  that  the  spurs  acting  as  fulcruras  are  unnecessary,  the 
spring  of  the  arch  g-ained  through  the  pry  of  the  sheaths  of  the  anchor- 
bands   usually    being    ample.     It    is   well,   however,  to    reinforce  this 


TREATMENT. 


809 


anchorage  with  intermaxillary  anchorage ;  that  is,  stretching  a  delicate 
rubber  ligature  from  the  hook  attached  to  the  upper  expansion  arcli  to 
one  upon  the  lower  expansion  arch,  or  to  attachments  on  the  lower 
canines,  as  in  Fig.  762. 

The  best  means  of  retaining  teeth  so  elevated  is  to  allow  the  expan- 
sion arch  to  remain  in  position  the  requisite  time. 

Fig.  762. 


Fig.  763  shows  another  case  of  pronounced  infra-occlusion  of  the 
incisors,  canines,  and  premolars,  principally  of  the  upper  arch.  This 
condition  was  augmented  by  the  second  molars  being  in  supra-occlusion, 
they  being  the  only  teeth  that  came  in  contact  when  the  jaws  were 
closed. 

Fig.  763. 


The  plan  of  treatment  which  seemed  most  advisable  was  the  short- 
ening of  the  second  molars  and  the  lengthening  of  all  the  incisors  and 
canines.  This  was  accomplished  by  means  of  the  spring  of  the  expan- 
sion arches  reinforced  by  intermaxillary  anchorage,  exactly  as  described 
in  the  last  case. 


810 


ORTIIoltoSTlA. 


All  of  the  lower  iiu-isors  ami  the  caiiines  were  handed  with  delicate 
neatly  fitting  bands  made  from  the  thinnest  band  material  (C).  These 
bands  were  to  prevent  the  ligatures  from  slipping  oft'  the  teetli.  The 
upper  lateral  incisors  and  canines  were  banded  in  like  manner  for  the 
same  purpose.  Bands  were  unnecessary  on  the  upper  centrals,  as  the 
ligatures  were  twisted  above  the  gingiva  on  these  teeth,  thereby  pre- 
venting their  slipping  off".  Ligatures  of  the  finest  wire  were  used  in 
ligating  the  teeth  to  the  expansion  arches,  after  the  latter  had  been  bent 
to  give  the  greatest  downward  spring  to  the  upper  and  upward  spring 
to  the  lower.  The  force  from  this  spring  was  intensified  by  two  of  the 
delicate  rubber  ligatures,  which  were  stretched  from  one  arch  to  the 
other  and   made   to  engage  spurs  which   had  been  soft-soldered  to  the 

Fig.  76-1. 


expansion  arches  opposite  the  canine  teeth.  The  effect  of  these  liga- 
tures was  not  only  that  of  assisting  in  elevating  the  incisors  and  canines 
in  their  sockets,  but  also  the  depressing  of  the  second  molars,  which 
was  probably  effected  to  some  extent. 

It  will  be  noted  that  the  left  lower  first  molar  is  in  buccal  occlusion, 
and  that  its  antagonist  is  in  lingual  occlusion.  The  expansion  arches, 
before  insertion,  were  bent  to  give  spring  for  the  correction  of  these 
positions.  The  desired  movements  of  all  the  teeth  were  gradually 
effected  until,  after  about  three  months,  or  at  vacation  time,  a  study 
model  was  taken,  which  shows  the  gratifying  results  illustrated  in  Fig. 
764. 

The  safest  way  for  retaining  this  and  similar  cases  is  to  allow  the 
expansion  arches  to  remain  in  place,  with  the  occasional  use  of  one  of 
the  delicate  rubber  ligatures. 


TREATMENT.  811 

Later,  the  fine  adjustment  of  the  occlusion  ^vill  be  effected,  and,  if 
necessary,  the  slight  shortening  of  the  second  molars  by  grinding. 

It  would  seem  that  quite  a  protracted  period  of  retention  would  be 
required  in  this  case  in  order  to  permit  the  development  of  the  neces- 
sarily large  amount  of  alveolar  process. 

Fig.  765.  Fig.  766. 


It  is  highly  desirable  that  such  cases  be  undertaken  as  early  as  pos- 
sible. It  is  doubtful  whether  they  should  ever  be  undertaken  much 
later  than  the  age  of  seventeen.  They  should  always  be  handled  in 
the  most  gentle  manner  in  order  to  avoid,  in  the  very  extensive  move- 
ment necessary,  undue  inflammation  and  possible  disastrous  results  to 
the  pulp. 

Such  cases  present  many  points  of  interest,  one  which   impresses  the 

Fig.  767. 


writer  being  the  readiness  with  which  the  attachment  of  the  gum  and 
alveolar  process  follows  the  teeth  in  such  extensive  movements. 

Fig.  765  shows  another  more  or  less  common  type  of  mal-occlusion 
belonging  to  this  class,  as  will  readily  be  recognized  by  the  position  of 
the  molars.  All  of  the  upper  anterior  teeth  are  in  lingual  occlusion, 
while  the  lower  have  been  forced  into  slight  labial  occlusion. 


812  ORTHODONTIA. 

Tlu'  upper  incisors  were  laced  to  tlie  expansion  arch  with  wire  liga- 
tures, and  all  carried  lahially  by  tightening  the  nuts  in  front  of  the 
tubes  on  the  anchor  tectli — the  first  molars.  It  will  be  seen  in  the  next 
engraving  (Fig.  ?()())  that  plain  bands  encircle  the  lateral  incisors  to 
prevent  the  sliding  of  the  ligatures,  while  plain  ligatures  are  used  on 
the  centrals.  Tiic  engraving  illustrates  a  study  model  made  after  com- 
pletion of  tooth  movements  and  just  before  the  appliance  was  removed. 

The  U[)per  teeth  were  moved  outward  to  correct  positions,  as  shown 
in  the  case  compk'tcd  (Fig.  767),  in  just  seven  days.  The  jxitient  was 
a  boy  sixteen  years  of  age.  It  is  doubtful  whether  this  could  have  been 
accomplished  so  easily  and  quickly  by  any  other  known  method. 

The  appliance  was  allowed  to  remain  upon  the  teeth  passively  for 

Fig.  768. 


ten  days  before  removal,  when  occlu^iou  alone  was  depended  upon  for 
retention. 

No   effort  was  made  to  change   the  positions  of  the  lower  incisors, 
as  it  was  known  that  the  necessary  change  would  be  effected  by  occlu- 


sion. 


In  the  treatment  of  all  similar  cases  there  is  a  strong  tendency  on 
the  part  of  many  to  perpetuate  the  antiquated  ])ractice  of  applying  some 
form  of  gag  to  keep  the  jaws  apart  and  prevent  the  occlusion  from 
interfering  with  the  movement  of  the  teeth.  Such  practice  should  l)e 
obsolete.  A  good  appliance  will  effect  the  movement,  regardless  of  the 
slight  hindrance  offered  l)y  occlusion,  which  is  reduced  to  the  minimum 
by  the  patient's  natural  avoidance  of  irritating  the  tender  moving  teeth. 


TREATMENT.  813 

Fig.  768  shows  the  left  side  of  two  models  of  a  case,  before  and 
after  treatment.  The  occlusion  on  the  right  side  was  normal.  On  the 
left  (upper  model)  the  lateral  halves  of  both  arches  were  shortened,  the 
upper  permanent  lateral  incisor  being  in  contact  with  the  first  premolar. 
There  was  a  shrunken  appearance  of  the  mouth,  and  the  incisors  were 
shifted  from  the  median  line.  This  condition  was  the  result  of  the 
unfortunate  and  unnecessary  loss  of  the  deciduous  upper  canine  and 
the  first  and  second  deciduous  lower  molars. 

It  needs  but  slight  reflection  to  realize  what  must  follow  as  the 
result  of  this  unfortunate  loss  of  teeth.  The  permanent  upper  canine 
on  erupting  must  be  forced  into  pronounced  labial  occlusion,  with 
marked  disturbance  of  the  left  lateral  and  central,  while  in  the  lower 
jaw  marked  mal-occlusion  must  follow  the  eruption  of  the  premolars. 

The  treatment  clearly  indicated  was  the  lengthening  of  the  left 
lateral  halves  of  both  arches  and  the  moving  forward  of  the  centrals 
and  the  shifting  of  their  positions  to  be  in  harmony  with  the  median 
line. 

This  was  accomplished  in  both  arches  simultaneously  by  means  of 
expansion  arches,  bands,  and  ligatures.  No  bands  on  the  teeth  to  be 
moved  were  necessary.  The  incisors  were  laced  to  the  arch  with  plain 
ligatures,  as  in  A,  Fig.  684.  The  notches  in  the  ribbed  arches  for  pre- 
venting the  ligatures  on  the  upper  lateral  incisor  and  lower  canine  from 
slipping  were  placed  about  opposite  the  middle  of  the  centrals,  so  that 
force  produced  by  tightening  the  nuts  in  front  of  the  anchor  sheaths  on 
the  first  molars  exerted  a  direct  mesio-labial  movement  of  these  teeth, 
and  as  the  nuts  were  tightened  only  on  the  affected  side  the  lateral 
shifting  of  the  incisors,  as  the  arches  were  lengthened,  was  natural  and 
easy. 

The  result  of  treatment  is  shown  in  the  lower  model,  the  sides  of 
the  arches  having  been  sufficiently  lengthened  to  admit  of  the  eruption 
of  the  upper  canine  and  lower  premolars. 

Retention  was  effected  by  means  of  a  section  of  G  wire  which 
engaged  E  tubes,  one  of  which  was  soldered  at  its  end  to  the  mesial 
surface  of  a  No.  2  band  on  the  molar,  and  the  other  similarly  attached 
to  the  distal  surface  of  a  band  on  the  cuspid.  A  few  pinches  from  the 
regulating  pliers  slightly  lengthened  the  wire,  giving  a  firm  resistance 
to  the  distal  tendency  of  the  cuspid  (Fig.  709).  A  similar  device  (Fig. 
710)  was  placed  upon  the  upper  lateral  and  first  premolar.  These 
were  worn  until  the  eruption  of  the  teeth  made  their  use  no  longer 
necessary.  This  is  a  very  desirable  method  of  retention  in  all  similar 
cases. 

In  the  model  on  the  right  of  the  engraving  (Fig.  769)  is  shown  a 
case  from  which  several  valuable  lessons  may  be   learned.     The  case 


814  ORTHODONTIA. 

was  that  of  a  young  lady  sixteen  years  okl.  Two  years  ])revioiis 
to  tlie  making  of  this  model  her  teeth  were  practically  faultless 
in  occlusion,  and,  with  the  exception  of  the  first  lower  molar  on 
the  left,  of  excellent  structure  and  color.  At  this  time  this  molar 
was  lost  through  neglect  of  caries,  the  result  being  the  inevitable 
tipping  forward  of  the  second  molar.  The  looking  of  its  inclined 
ocdusjil  planes  witli  those  of  the  upper  second  molar  caused  the  carry- 
ing distally  of  this  side  of  the  lower  Jaw,  and  at  the  same  time  some 
forward  movement  of  all  the  anterior  teeth  of  the  upjier  arch,  the  result 
being  the  gradual  shifting  to  nearly  complete  distal  occlusion  of  the 
teeth  in  this  lateral  half  of  the  lower  arch  anterior  to  the  space. 
At  the  same  time  pressure  from  the  upper  lip  was  gradually  molding 
the  upper  arch  to  the  diminishing  size  of  the  lower,  as  shown  by  the 
bunching  of  the  incisors. 

The  treatment  clearly  indicated  was  lengthening  of  the  lateral  half 

Fir;.  709. 


of  the  lower  arch,  the  tipping  to  an  upright  position  of  the  second 
molar,  and  th.e  correction  of  the  positions  of  the  teeth  in  the  upper  arch, 
or  the  restoration  of  the  occlusal  planes  to  their  original  positions. 

The  truing  of  the  positions  of  the  upper  teeth  was  accomplished  by 
means  of  the  expansion  arch,  bauds,  and  ligatures  in  the  usual  way, 
while  the  lengthening  of  the  lateral  half  of  the  lower  arch  was  accom- 
plished in  the  same  manner  as  in  the  case  last  described.  The  tipping 
to  an  upright  position  of  the  molar  was  effected  by  force  exerted  upon 
the  nut  in  front  of  the  anchor  sheath,  and  also  by  bending  the  expan- 
sion arch  at  the  point  where  it  entered  the  sheath  so  as  to  give  a  spring 
or  jirv  upward  on  the  mesial  end  of  the  slunith  and  a  downward  pry  on 
its  distal  end.  The  result  is  shown  in  the  model  of  the  completed  case 
on  the  left  of  the  engraving. 

The  ])atient  was  then  referred  back  to  her  dentist  for  the  insertion 
of  an  artificial  substitute  for  the  lost  molar,  which  being  provided,  iu 


TREATMEST. 


81.5 


the  form  of  a  bridge,  .-served  the  double  purpose  of  mastication  and 
retention.  The  requirements  of  orthodontia  and  bridging  are  sach  as 
should  induce  a  closer  study  of  their  relations. 

A  point  we  would  empha-size  in  relation  to  this  case  is  that  the 
change  taking  place  in  this  previously  faultless  arch,  as  a  result  of  the 
loss  of  this  first  molar,  is  what  must  and  does  always  follow  the  loss 
of  this  tooth.  Examine  a  thousand  similar  cases,  and  as  many  similar 
results  will  be  found. 

It  will  be  noticed  that  none  of  the  teeth  on  this  side  occludes  in  the 
model  on  the  right,  but  that  they  merely  touch  at  irregular  intervals 
and  are  practically  worthless  for  mastication.  AVhat  we  would  espe- 
cially emphasize  in  this  connection  is  that  the  odcmtocide  is  not  relieved 
of  his    responsibilities   by   the    extraction,    but    he    roust    immediately 


Fig.  ,70. 

^^ 

'KK 

te^^l^^A^^-   %        jr 

■it*'-' ' 

!■ 

■H^^HI^M 

^■iriHl' 

replace  the  lost  tooth  by  some  form  of  artificial  suljstitute  or  be  certain 
that  he  has  done  that  which  will  in  time  result  as  here  .shown — ^practi- 
cally the  ruination  of  the  occlusion  on  the  side  of  the  arch  from  which 
he  has  extracted  the  tooth. 

Figs.  770  and  771  show  from  both  right  and  left  sides  a  most  unfor- 
tunate result  following  the  extraction  of  the  four  first  permanent  molars, 
which,  though  perfectlv  sound,  were  removed  at  the  age  of  nine  years 
with  the  idea  of  preventing  mal-occlusion  of  the  teeth  by  making  space, 
and  how  successful  the  effort  was  is  readily  seen.  This  is  but  the  natural 
result.  Not  only  have  the  teeth  that  remained  been  rendered  almost 
useless  for  mastication,  but  in  recent  years  there  has  be'^n  chronic  p-^^rioe- 
raentitis,  due  to  the  pressure  of  the  mal-occlusion  on  the  rnolars  in  their 


816 


ORTHODONTIA. 


tipped  and  abnormal  positions.  The  facial  lines  were  also  e^reatlv  marred 
by  the  arrest  in  the  development  of  the  alveolar  process,  for  without  the 

wedoiiijr  iiiHiienoe  of  those  most  important  teeth — the  first  molars the 

teeth  anterior  could  not  be  pushed  forward  by  the  development  and 
eruption  of  the  second  and  thinl  molars  to  |)roperlv  contour  the  face. 

(iold-cappino;  of  the  leaning  molars  was  resorted  to  in  this  case  to 
iinprove  the  occlusion,  only  to  aggravate  the  condition,  for  the  gold 
crowns  only  made  a  longer  leverage  for  the  occlusion  to  act  upon  in 
tipping  the  teeth. 

There  was  but  one  logical  and  rational  plan  of  treatment,  namely,  to 
gain  the  space  lost  by  the  molars  and  replace  these  teeth  by  artificial 
substitutes. 

The    same    general   plan   of  treatment    was    followed    to   accomplish 


Kk;.  771. 

^■■^■l 

1           -                      '^ 
1                                ^ 

Ace^^t           I 

^K'^t 

H 

■fcH^ 

^^^^l^H^^^^dt  ■ 

1^ 

Vc    '^               _ 

these  movements  as  in  gaining  the  space  for  the  missing  first  molar  in 
the  case  last  described.  All  four  second  molars  were  encircled  by  D 
bands,  but  before  placing  the  lower  bands  in  position  the  sheaths  were 
resoldered  to  align  jirojierly.  The  ribbed  expansion  arches  were 
inserted,  in  which  hook-like  notches  were  made  just  anterior  to  the  four 
cuspids.  The  heavy  wire  ligatures  were  looped  over  the  second  premolars 
and  brought  forward  to  engage  these  notches  and  firmly  twisted,  thereby 
at  once  exerting  a  strong  tension  in  a  mesial  direction  on  all  the  second 
premolars,  which  in  turn  was  transmitted  to  the  first  premolars,  canines, 
and  laterals.  This  force  was,  of  course,  reciprocated  to  the  distal  move- 
ment of  the  second  molars,  by  which  it  w^as  in  turn  transmitted  to  the 
third  molars. 


TREATMENT. 


817 


This  appliance  having  been  most  carefully  and  firmly  adjusted,  it 
will  be  seen  that  the  occasional  tightening  of  the  nuts  in  front  of  the 
sheaths  must  result  in  the  gradual  carrying  of  all  the  teeth  anterior  to 
the  space  forward,  and  at  the  same  time  the  movement  of  all  the  molars 
distally.  The  most  difficult  problem  apprehended  was  to  gradually 
effect  at  the  same  time  the  tipping  to  an  upright  position  of  the  greatly 
leaning  lower  second  molars.  Yet  by  taking  advantage  of  the  possi- 
bilities of  the  upward  pry  of  the  expansion  arch,  this  was  readily 
effected.  It  was  accomplished  by  aligning  the  sheaths  of  the  anchor- 
bands  so  tliat  when  the  expansion  arch  was  inserted  its  anterior  part 
aligned  low  down  upon  the  gums,  then,  by  springing  the  arch  upward 
to  its  correct  position  just  above  the  gingival   margins  of  the  anterior 

Fig.  772. 


teeth  and  ligating  it  in  this  position  to  the  incisors,  a  strong,  steady 
upward  leverage  was  constantly  exerted  upon  the  leaning  teeth. 

As  the  movements  of  the  teeth  progressed  gradually  the  upward 
s})rnig  of  the  arch  became  insufficient,  necessitating  the  removal  of  the 
lower  D  bands  and  the  resoldering  of  their  sheaths  in  order  to  again 
intensify  the  direction  of  this  upward  spring. 

Notwithstanding  the  advanced  and  supposedly  unfavorable  age  of 
the  patient  (thirty-eight  years)  for  the  treatment  of  mal-occlusion,  it 
bemg  the  most  advanced  age  recorded  for  such  an  extensive  operation, 
the  writer  was  agreeably  surprised  to  find  that  the  teeth  moved  quite  as 
easily  and  fully  as  rapidly  as  in  the  usual  case  of  a  miss  of  eighteen, 
52 


818  ORTHODONTIA. 

and  w  illi  no  unfavorable  symptoms  ioll()\vin<r  the  distal  movement  of 
the  molars. 

The  result  in  oeelusion  is  shown  in  Fig.  772.  It  will  be  seen  that 
all  the  teeth  anterior  to  the  spaee  have  been  moved  well  forward,  as 
well  as  the  molars  havini>:  been  moved  distally  and  into  correct  rela- 
tions. 

Retention  was  effected  by  two  vulcanite  plates  which  bore  ajjainst 
the  lintj^ual  surfaces  of  the  anterior  teeth  and  filled  the  spaces  of  the 
missinti^  molars,  and  the  case  was  finally  referred  back  to  the  patient's 
dentist,  who,  alter  some  months,  skilfully  inserted  some  very  perfect 
bridges. 

The  remarkable  changes  in  the  sizes  of  the  arches  and  the  relations 
and  inclinations  of  the  teeth  are  naturally  reflected  in  the  lines  of  the 
mouth  in  relation  to  the  other  features,  as  will  be  seen  by  comparing 
the  lines  of  the  face  before  and  after  treatment  in  Fig.  626. 

Great  as  are  the  changes  in  the  facial  lines,  the  close  student  will 
observe  that  there  is  not  complete  normal  contour  of  the  mouth,  which 
is  but  natural  when  we  think  of  how  the  arches  were  robbed  in  youth 
of  that  normal  wedging  influence  of  the  first  molars,  so  necessary  to 
efl'ect  the  normal  development  and  normal  contour  of  the  facial  lines. 

Let  us  again  try  to  impress  the  student  with  the  fact  that  even 
though  the  extraction  of  a  molar  through  neglect  of  caries  may  become 
necessary,  its  loss  is  so  direct  and  so  serious  in  its  relations  that  its 
replacement  becomes  his  immediate  duty. 

Another  point.  If  dentists,  before  making  bridges,  would  refer 
their  patients  to  competent  orthodontists,  far  better  results  would  follow. 
The  placing  of  bridges  on  leaning  piers  is  as  unnecessary  as  it  is  unme- 
chanical  and  abnormal. 

Class   II. — Division   1. 

It  will  be  remembered  that  the  distinguishing  characteristics  of 
cases  belonging  to  this  class  and  division  are  distal  occlusion  of  both 
lateral  halves  of  the  low^er  arch,  more  or  less  undeveloped  mandil)lc, 
narrowed  upper  arch,  lengthened  and  protruding  upper  incisors,  and 
lengthened  lower  incisors.  It  will  also  be  remembered  that  these 
patients  are  in  almost  every  instance  affected  Avith  some  form  of  nasal 
obstruction  necessitating  mouth-breathing,  which  usually  begins  at  an 
early  age,  causing  the  mouth  to  be  held  open  almost  constantly  and  the 
lips  and  buccal  muscles  to  act  abnormally.  The  upper  lip  is  drawn 
upward  in  the  effort  at  breathing  and  fails  to  develop  in  size  and  func- 
tion, exercising  little,  if  any,  restraint  u])on  the  labial  movement  of 
the  incisors.  Their  protrusion,  therefore,  becomes  more  and  more  jiro- 
nounced,  partially  as  a  result  of  pressure   from   the  tongue  and  narrow- 


RETENTION. 


819 


ing  of  the  arch  through  mal-occlusion  and  the  action  of  the  buccal 
muscles,  but  principally  because  the  lower  lip  is  so  frequently  forced 
against  their  lingual  surfaces  in  swallowing  and  in  the  effort  at  moisten- 
ing the  mucous  membrane  of  the  mouth.  Both  upper  and  lower  incisors 
become  lengthened,  probably  from  lack  of  function,  so 
that  the  occlusal  edges  of  the  lower  are  frequently  in 
contact  with  the  raucous  membrane  of  the  hard  palate. 

It  is  a  common  mistake  to  suppose  that  this  form  of 
mal-occlusion  is  the  result  of  overdevelopment  of  the 
upper  jaw.  The  writer  has  never  seen  a  case  where  it 
seemed  to  him  that  this  condition  really  existed.  The 
marred  facial  lines  and  the  condition  of  the  upper  jaw 
and  teeth  are  but  the  natural  results  of  distal  occlusion, 
recession  of  the  lower  jaw,  and  the  consequent  modified 
functions  of  the  lips  and  cheeks.  If  it  were  possible 
in  the  case  of  any  person  with  normally  balanced  fea- 
tures and  teeth  in  normal  occlusion  to  force  the  lower  jaw  back 
until  the  teeth  were  in  distal  occlusion,  narrow  the  upper  arch,  com- 
pel mouth-breathing,  move  forward  and  slightly  lengthen  the  upper 
incisors  and  canines,  and  shorten  the  upper  lip,  we  would  then  have  a 
typical  case  of  this  class  of  deformities.  It  seems  quite  probable  that 
all  of  these  conditions  have  been  gradually  brought  about,  at  least  up 
to  the  period  of  the  abnormal   locking  of  the  first  permanent  molars,  as 


E.  H.A. 


Fig.  773. 


a  result  of  mouth-breathing.  But  after  the  eruption  of  the  four  first 
permanent  molars  and  the  locking  of  the  lowers  into  distal  occlusion, 
each  succeeding  permanent  tooth  to  erupt  is  forced  to  lock  abnormally, 
thereby  furthering  the  abnormal  conditions  existing  in  these  cases.  The 
nasal  obstruction  may  have  been  so  slight  at  first  as  to  occasion  mouth- 


820 


ORTHODONTIA. 


breatliing  only  at  intervals  and  may  have  disapjx'arcd  entirely  later, 
but  if"  it  was  sufficient  at  the  time  of  the  eruption  of  the  first  perma- 
nent molars  to  defleet  the  intemh^d  normal  relations  of  the  inclined 
planes  of  these  teeth  into  abnormal  (distal)  relations — but  a  few  days 
would  be  necessary  to  accomplish  this — the  nucleus  of  conditions  would 
be  established  which  inevitably  must  pro<;ress  until  all  of  the  condi- 
tions of  a  typical  case  have  developed,  and  after  once  established  it  is 
remarkable  what  similarity  exists  between  these  cases,  the  differences 
being  only  in  degree,  and  that  usually  in  proportion  to  the  age  of  the 
patient. 

Treatment. — In  the  treatment  of  these  cases  the  new  and  logical 
plan  to  be  followed  is  the  restoration  to  normal  occlusion  of  all  of  the 
teeth,  beginning  with  the  correction  of  the  mal]K)sitions  of  the  first 
molars,  and  following  in  the  order  of  the  teeth  mesially,  ending  with 


Fi(i.  774. 


the  incisors  instead  of  beginning  with  the  symptoms,^  as  it  were,  or 
with  the  protruding  upper  incisors,  as  with  the  old  plan  of  treatment, 
of  which  we  shall  speak  later. 

Fig.  773  shows  a  most  pronounced  case  belonging  to  this  class.  It 
will  be  noted  that  all  of  the  characteristics  of  a  typical  case  are  present. 

The  combination  of  appliances  already  shown  in  Fig.  683  and 
described  in  the  section  on  Adjustment  and  Ojieration  of  A])pliances 
were  adjusted,  and  in  a  short  time  the  first  upper  molars  were  carried 
distally  fully  one-half  the  width  of  a  premolar  tooth.  ^Meantime  the 
lower  teeth  had  been  moved  somewhat  forward.  Their  further  progress 
was  stayed  by  ligating  the  lower  incisors  to  the  expansion  arch,  thereby 
enlisting  stationary  anchorage,  as  described  on  page  750. 

•  Meeting  of  the  Stomatological  Institute,  October,  1903.  Also  International  Denial 
Journal,  October,  1904,  Angle. 


TREATMENT.  821 

The  anchor-bands  on  the  upper  first  molars  were  now  removed,  X 
bands  placed  on  the  upper  second  premolars,  and  force  again  exerted 
from  the  rubber  ligatures,  and  these  teeth  moved  well  back  against  the 
first  molars. 

Fig.  774  shows  the  upper  arch  at  this  stage.  The  nuts  on  the  upper 
expansion  arch  were  now  turned  well  back  so  that  the  full  force  of  the 

Fig.  775. 


expansion  arch,  through  the  rubber  ligatures,  was  received  upon  the 
upper  incisors.  The  writer  now  usually  prefers  to  substitute  the  arch 
B  at  this  stage  for  the  expansion  arch.  In  a  little  while  the  incisors  and 
canines  had  been  carried  back  the  proper  distance.    Study  models  taken 


in  plaster  at  this  time,  with  the  teeth  in  occlusion  and  with  the  retaining 
devices  in  situ,  are  shown  in  Fig.  775,  and  Figs.  776  and  777  illustrate 
the  case  by  better  models  taken  six  months  later,  or  at  the  time  of 
the  final  removal  of  all  retaining  devices. 


822 


ORTHODONTIA. 


The  case  was  retained  by  the  (Unice  shown   in   Figs.  725  and  789, 
consisting  of  bands  proviih'd  with  a  Ikuvv  spur  made  to  close  in  front 


Fig.  777. 


of  a  plane  of  metal  attached  to  a  band  on  an  opposing  upper   tooth. 
This  was  worn   in  this  case  on  both   sides  of  the  arch,  attached  to  the 


Fk;.  778. 


first  premolars.     Later  this  was  discarded  and  the  retention  shifted  to  the 
canines,  making  use  of  the  canine  device  shown  in  Fig.  726.     This  has 


TREATMENT.  823 


for  a  long  time  been  a  favorite  with  the  writer,  although  the  molar  and 
premolar  modifications  are  equally  valuable  and  quite  as  often  required, 


Fig.  779. 


the  varying  peculiarities  of  each  case  determining  which  is  needed.    The 
wearing  of  these  devices  until  the  molars  have  become  thoroughly  locked, 


Fig. 


usually  for  a  period  of  six  months,  will  be  sufficient.     It  is  well,  how- 
ever, to  adopt  a  principle  in  the  retention  of  these  teeth,  the  same  as  has 


824  ORTlfODOSTfA. 

long  been  known  to  l)o  good  practice  in  all  cases  of  retention  ;  that  is, 
intensifying  the  positions  of  the  teeth  or  holding  them  rather  in  advance 
of  the  positions  they  shall  nltiniately  occupy,  thus  allowing  for  the 
slight  settling  hack  whicii  is  nearly  always  found  to  lollow  in  all  cases 
after  retention. 

The  retention  of  the  ]>rotrn(ling  incisors  may  he  effected  in  sevend 
ways.  The  one  ])referred  by  the  writer  is  after  the  method  shown  in 
Fig.  712,  with  the  bands  on  the  first  premolars  instead  of  on  the  lateral 
incisors. 

Figs.  778  and  779  show  the  occlusion  from  the  right  and  left  sides 
of  another  typical  case,  with  the  usual  characteristics,  and  Figs.  780  and 
781  show  the  occlusion  after  the  case  has  been  treated  exactly  as  de- 
scribed in  the  last  case.     The  resultant  changes  in  occlusion  are  clearly 

Fi(i.  781. 


manifest  in  the  better  balance  of  the  facial  lines,  as  will  be  seen  by 
comparing  Fig.  783,  which  represents  the  face  after  treatment,  with 
Fig.  782,  which  represents  the  face  before  treatment. 

Space  will  not  permit  the  report  of  a  number  of  these  cases,  but  as 
there  is  such  remarkable  similarity  between  them,  with  requirements  in 
treatment  so  nearly  alike,  it  would  seem  unnecessary  to  multiply  cases. 

It  should  be  remembered  that  the  greatest  success  ultimately  attained 
in  establishing  harmony  and  the  best  balance  of  the  mouth  and  lower  part 
of  the  face  with  the  rest  of  the  features  will  be  by  beginning  treatment 
early ;  that  is,  establishing  the  normal  locking  of  the  first  molars  as  soon 
after  their  eruption  as  possible,  and  thereby  permitting  nature  to  act 
normally    in   her   subsequent  development   of  the   jaws  and  muscles, 


TREATMENT. 


825 


instead  of  waiting  until  there  is  such  inharmonious  development  in  the 
sizes  of  the  jaws  as  must  follow  as  we  approach  maturity. 

The  dental  student  should  learn  the  great  advantages  of  early  treat- 
ment of  these,  as  well  as  of  all  cases  of  mal-occlusion,  and  the  great 
disadvantages  of  delaying  treatment. 

There  were  formerly  much  in  vogue  two  other  plans  for  establishing 
harmony  in  the  sizes  of  the  dental  arches  in  cases  belonging  to  this 
division  of  this  class.  The  first,  and  one  which  has  been  longest  prac- 
tised, necessitated  the  sacrifice  of  two  upper  premolars,  usually  the  first, 
followed  by  the  retraction  of  the  canines  and  incisors,  in  order  to  har- 
monize the  sizes  of  the  dental  arches,  and  many  are  the  devices  which 
have  been  employed  for  this  purpose.  Some  of  them  are  extremely 
crude  and  defective,  especially  in  the  principles  of  anchorage,  usually 


Fig.  782. 


Fig.  783. 


relying  upon  the  stability  of  the  first  molars  for  overcoming  the  resist- 
ance of  the  moving  teeth,  the  result  in  nearly  every  instance  being  the 
displacement  mesially  of  the  anchor  teeth,  usually  in  about  the  same 
proportion  as  the  anterior  teeth  were  displaced  distally. 

Other  devices  depended  on  a  combination  of  molar  and  occipital 
anchorage,  with  better  results.  The  writer's  appliances  for  accomplish- 
ing the  retraction  of  the  incisors  and  canines  are  shown  in  Figs.  784 
and  655.  It  will  be  seen  that  stationary  anchorage  of  the  molars  is 
combined  with  occipital  anchorage,  making  use  of  the  traction-screws, 
as  in  Fig.  678,  in  combination  with  the  B  arch,  the  distal  ends  of  the 
arch  being  inserted  in  short  sheaths  attached  to  the  long  sheaths  of  the 
traction-screw.     The  anterior  part  of  the  arch  B  is  kept  in  contact  with 


82(; 


ORTHODOSTIA. 


the  l.ihial  surfaces  of  the  incisors  (upper)  by  being  made  to  rest  in 
notches  formed  in  the  united  ends  of  plain  bands  on  these  teeth,  made 
from  the  band  material  F,  as  shown  in  C,  Fig.  7tS5. 

Force  derived   from    the   headgear  through   heavy  elastic   bands  is 
transmitted   to  the  ball-and-socket  joint   between   the  traction-bar  and 

V\ii.  784. 


Fig 


the  arch  B,  to  the  centre  of  the  arch  B.  Additional  force  from  inter- 
maxillary anchorage  may  also  be  enlisted  by  use  of  the  rubber  ligatures 
made  to  engage  sheath-hooks  on  the  arch  B  and  the  anchor-bands  on  the 
lower  molars,  as  already  described  in  the  first  plan  of  treatment.  Al- 
though the  device  here  shown  is  unquestionably  the  most  simple  and 
efficient  for  carrying  out  this  plan  of  treatment,  yet 
the  principle  of  treatment  itself  is  obviously  wrong 
and  ought  rarely,  if  ever,  to  be  employed,  for  at  best 
it  is  only  palliative,  making  one  deformity  to  patch  up 
another.  There  is  always  a  strained  and  unnatural 
look  given  to  the  mouth,  following  this  plan  of  treat- 
ment. The  writer  has  yet  to  see  a  single  instance 
where  the  facial  lines  have  been  much  improved  over 
their  former  condition,  and    in   some   instances  thev 

C  H.  A,  * 

had  been  made  radically  worse  after  treatment  by  this 
method.  Fig.  H27  shows  the  facial  lines  of  one  patient  after  such 
treatment. 

This  j)lan  of  treatment  was,  of  course,  excusable  before  the  intro- 
duction of  the  Baker  anchorage  ;  in  fact,  it  was  then  the  only  one  that 
might  safely  be  relied  upon,  but  with  the  progressive  orthodontist  it  can 
no  longer  be  in  favor,  and  we  believe  it  is  destined  to  become  obsolete 
except  in  the  rarest  of  instances. 


TREATMENT. 


827 


Another  plan  of  treatment,  introduced  by  Dr.  Norman  W.  Kingsley, 
consisted  in  what  he  termed  "jumping  the  bite,"  or  shifting  the  position 


Fig.  786. 


Fig.  787. 


of  the  mandible  and  lower  teeth  from  distal  to  normal  occlusion  (which 
any  one  with  distal  occlusion  can  do  voluntarily),  and  holding  the  jaw 


828  OltTIlODOSTIA. 

in  tills  position  Uy  sonic  t'orni  ol"  iiit'cliaiiicHl  dcvici'  until  citlKM'  tlic  jaw 
or  toniporo-maxillarv  articulation,  or  hothjiad  supposedly  hccn  nioditicd 
to  l)c  in  harmony  with  the  teeth  in  their  ct»rreeted  ocelnsion  or  normal 
relations,  when,  it  was  supposed,  there  would  he  no  recurrence  ol'  the 
former  condition. 

In  order  to  establish  harmony  in  the  occlusal  inclined  planes  in  this 
manner  it  was,  of  course,  necessary  to  first  place  the  teeth  of  the,u])per 
arch  in  harmony  with  their  normal  line  of  occlusion  ;  that  is,  widening 
this  arch  somewhat  in  the  region  of  the  canines  and  ])r(iiiolars,  and 
moving  lingually  the  protruding  incisors,  which  was  done  bv  various 
forms  of  mechanical  devices. 

This  plan  of  treatment  has  occasioned  much  controversy,  its  practi- 
cahilitv  being  doubted  by  many  and  stoutly  detended  l)v  others.  The 
great  advantage  of  the  method,  were  it  practicable,  over  the  one  last 

Fig,  788. 


described  must  be  apparent  to  all,  for,  in  addition  to  the  first  requisite 
in  the  treatment  of  mal-occlusion,  the  complete  restoration  to  normal 
occlusion,  it  made  possible  the  restoration  of  the  chin  and  lower  jaw  to 
harmony  of  balance  with  the  rest  of  the  face.  No  wonder  it  should 
have  strong  advocates,  especially  by  those  of  Dr.  Kingsley's  type,  who 
set  much  store  by  the  artistic  balance  of  the  face.  But,  as  we  shall  see, 
one  important  phase  of  the  conditions  contingent  on  this  plan  of  treat- 
ment has  been  overlooked  by  the  advocates  of  this  plan.  The  follow- 
ing case,  which  was  treated  after  this  plan,  and  reported  by  the  writer  in 
the  sixth  edition  of  his  3InI-of'clusion  of  the  Teeth  and  Fractures  of  the 
Maxilke,  will  illustrate  this.  The  case  was  that  of  a  boy  nine  years  of 
age.  It  will  be  seen  from  the  mal-occlusion  (Fig.  786)  and  the  facial 
lines  (Fig.  787)  that  the  case  is  one  typical  of  this  division  of  this  class. 
The  first  permanent  molars  on   both  sides  had  erupted  and   locked  in 


TREATMENT. 


829 


complete  distal  occlusion,  with  the  usual  narrowed  upper  arch  and  pro- 
truding upper  incisors. 

Fig.  788  shows  the  occlusal  aspect  of  the  upper  arch,  and  the  dotted 
line  in  the  engraving  indicates  the  relation  of  the  lower  teeth. 


Fig.  7 


The  teeth  of  the  upper  arch  were   moved  into  correct  relation  with 
their  proper  line  of  occlusion,  which   resulted    in  the   shortening  and 


Fig.  790. 


widening  of  the  arch.     The  lower  jaw  could  then  be  moved  forward, 
and,  upon  closing,  the  teeth  were  in  normal  occlusion,  as  shown  in  Fig. 


8.30 


ORTHODONTIA. 


789.     Closure  in  this  position  was  coinpcllcd  "oy  the  dcvieos  sliown  in  the 
engraving  and  already  described  in  retention. 

This  plan  of"  retention  was  eontinued  lor  a  ]ierio.l  of  two  years,  being 


Ki...  791. 


shifted   from  one  side  to  the  other,  and  oeeasionally  (■iiij)loyed   on   both 
sides  at  the  same  time.     It  will  be  noted  by  studying  the  profile  of  the 


Fig.  792. 

Hi) 

^ 

► 

■^ 

''.•* 

1 
Li 

H 

Ik 

young  man's  face.  Fig.  790,  that  the  lower  jaw  has  been  carried  well  for- 
ward, and  that  it  is  now  in  excellent  harmony  with  the  rest  of  the  face, 
in  marked  contrast  with  the  weak,  receding  chin  shown  in  Fig.  787. 


TREATMENT.  831 

Gradually  retention  was  discontinued,  and  the  deciduous  molars  were 
Jost  and  replaced  by  their  successors,  each  locking  norroally  with  its 
antagonist.  Some  two  years  after  all  devices  for  mechanical  retention 
had  been  removed,  a  study  of  the  occlusion  of  the  teeth,  as  shown  in  the 
correctly  made  models  (Fig.  791),  revealed  normal  occlusion.  The  writer 
felt  positive  he  had  succeeded  in  "jumping  the  bite."  Meantime  other 
cases  had  been  carried  on  with  equally  good  results.  But  an  important 
change  had  been  taking  place  in  this  case,  probably  from  the  very  begin- 
ning of  retention,  and  yet  unnoticed.  This  change  was  discovered  by 
a  comparison  of  the  profile  of  the  young  man  at  the  age  of  fifteen  (Fig. 
792)  with  the  photograph  of  his  profile  taken  at  the  time  of  completion 
of  treatment  (Fig.  790).  It  clearly  showed  that  instead  of  the  temporo- 
maxillary  articulation  having  been  modified  to  be  in  harmony  with  the 
new  position  of  the  mandible,  that  in  reality  the  mandible  had  gradu- 
ally worked  back  into  its  old  relations,  and  that,  too,  without  displacing 
the  normal  relations  of  the  inclined  occlusal  planes,  the  explanation  of 
this  being  that  the  crowns  of  the  upper  teeth  had  to  a  certain  extent 
been  tipped  distally  and  the  crowns  of  the  lower  teeth  more  or  less 
mesially ;  or,  in  other  words,  there  had  occurred  in  this  two-year  period 
of  retention  what  we  now  aim  to  accomplish  and  do  accomplish  in  a  very 
few  weeks  with  the  Baker  anchorage. 

Inspection  of  other  cases  showed  like  results.  In  one  instance  where 
retention  had  been  continuous  on  one  side  the  same  result  had  occurred, 
as  shown  in  Fig.  791,  but  on  the  other  side,  the  retaining  device  having 
been  lost  and  not  replaced,  as  the  mandible  regained  its  former  rela- 
tions, the  teeth  also  drifted  back  into  their  original  positions  of  distal 
occlusion. 

Class  II. — Division  1,  Subdivision. 

Practically  the  same  conditions  are  met  in  cases  belonging  to  this 
subdivision  as  are  found  in  the  main  division  just  described,  the  only 
difference  being  that  in  the  eruption  of  the  first  permanent  molars,  on 
one  side  only  have  they  locked  abnormally,  or  the  lower  in  distal  occlu- 
sion, the  teeth  on  the  other  side  being  locked  in  normal  occlusion. 

There  is  the  same  narrowing,  only  less  in  degree,  of  the  upper  arch, 
with  incisors  protruding,  in  many  instances  quite  as  much  as  in  the  full 
division,  and  with  facial  lines  marred  just  in  proportion  to  the  extent  of 
the  mal-occlusion. 

Fig.  793  shows  the  mal-occlusion  in  such  a  case,  from  both  right  and 
left  sides. 

The  treatment  indicated  is  the  same  as  in  all  cases  of  mal-occlusion, 
namely,  the  establishment  of  the  normal  relations  between  the  inclined 
occlusal  planes.     In  this  class  of  cases  this  is  brought  about  in  pre- 


832 


ORTHODONTIA. 


cisely  the  same  manner,  and  witli  the  same  combination  of  appliances 
used  in  tiie  same  way,  as  in  cases  belonging  to  the  I'nll  division,  or  in 
distal  occlnsion  on  both  sides,  except  that  the  sheath-hook  and  rubber 
ligatures  for  shifting  the  upper  teeth  distally  and  the  lower  teeth 
raesially  are,  of  course,  used  oidy  on  the  side  of  the  dental  arches  in 
distal  occlusion. 

Fio.  703. 


The  corrected  occlusion  is  shown  in  Fiu'.  7*J4.  Of"  course,  if  tliere 
is  required,  and  there  usually  is,  any  individual  tooth  movement  in 
either  of  the  dental  an-hes,  they  are  effected  at  the  same  time  as  the 
distal  shifting  of  the  upper  teeth  and  the  mesial  tipping  of  the   lower 


Fi...  794. 


1                            A'ie  13 

1 

l)y  means  of  sj)urred  bands  and  wire  ligatures,  as  already  described 
in  the  treatment  of  cases  belono^inir  to  Class  I. 

The  teeth  that  have  been  moved  are  retained  in  the  same  way  as 
already  described  for  cases  belonging  to  the  full  divisi(jn. 

Before  the  introduction  of  the  Baker  anchorage  the  only  practical 
plan  of  treating  these  cases  was  the  effecting  of  harmony  in  the  sizes 


TREATMENT.  833 

of  the  arches  by  sacrificing  the  first  upper  premolar  on  the  abnormal  side 
and  retracting  the  incisors  and  canine  to  close  the  space,  in  the  same 
manner  as  shown  on  both  sides  in  Fig.  784. 

It  is  thought  by  many  that  this  is  a  quicker  and  easier  plan  than  the 
one  first  described,  in  which  noruial  occlusion  is  established  through  the 
use  of  the  Baker  anchorage.  This,  however,  is  a  mistake,  as  the  former 
plan  is  quicker  and  easier  if  intelligently  managed. 

Class   II.,  Division   2. 

It  will  be  remembered  that  in  cases  of  mal-occlusion  belonging  to 
this  division  of  Class  II.,  as  in  those  of  Division  1,  the  teeth  of  the 
lower  arch  are  in  distal  occlusion  in  both  its  lateral  halves.  The  upper 
arch,  unlike  that  in  cases  of  Division  1,  which  is  abnormally  long  and 
narrow,  is  shortened,  with  incisors  bunched  and  overlapping,  as  in  Fig. 
795,  to  approximately  harmonize  in  size  with  the  anterior  part  of  the 

Fig.  795. 


lower  arch.  Unlike  the  conditions  of  the  other,  division,  the  incisors 
are  not  elevated  in  their  sockets,  owing,  probably,  to  their  more  nearly 
normal  function,  and  there  is  normal  respiration  and  lip  function,  but 
the  result  of  distal  occlusion  and  recession  of  the  jaw  and  chin  greatly 
mars  the  facial  lines,  as  shown  in  the  face  on  the  left  in  Fig.  622. 

The  logical  plan  of  treatment  in  this,  as  in  all  cases  of  all  classes, 
and  one  that  is  thoroughly  practical  and  not  difficult  of  accomplish- 
ment, especially  if  treatment  be  begun  early  and  intelligently  managed, 
is  the  establishment  of  normal  occlusion  of  the  teeth.  This  is  effected 
in  this  case  by  means  of  the  expansion  ar(;hes,  anchor-bands,  etc., 
adjusted  to  both  upper  and  lower  arches  in  the  usual  way,  and  made  to 
operate  through  spurred  bands  and  ligatures  to  effect  the  correct  adjust- 
ment of  the  irregular  incisors  and  canines,  the  same  as  already  described 
m  the  treatment  of  cases  belonging  to  Class  I.,  and  as  shown  in  Fig. 


,S;U  ORTHODONTIA. 

687.  At  the  .sanu-  time  the  niohir.s  and  i)reinolars  of  the  upper  arch 
are  being  .shifted  distally,  while  the  teeth  oi"  the  h)\ver  arch  are  being 
tip})ed  medially  l)v  niean.s  of  the  Baker  anchorage,  operated  exactly  as 
de.scribeil  in  the  treatment  of  cases  belonging  to  the  firrst  division  of 
this  class. 

Although  these  eases  are  apparently  more  com})licated  than  those 
of  the  lirst  division,  usually  they  are  more  easily  treated,  as  the  force 
to  move  into  correct  alignment  the  upper  incisors  reciprocally  assists  in 
moving  distally  the  upper  molars  and  premolars. 

Again,  as  the  patients  are  normal  breathers  and  keep  the  mouth 
closed  the  requisite  amount  of  time,  the  time  of  retention  of  the  molars 
by  mechanical  devices  is  shorter,  as  the  normal  locking  of  the  cusps — 
nature's  true  retaining  devices — thus  become  more  effective. 

The  same  plan  of  retention  by  means  of  the  spurs  and  planes 
attached   to  clamp-l)ands  on  molars  or  })remolars,  as  described  for  the 

Fk;.  796. 


retention  wf  cases  belonging  to  the  first  division,  and  in  the  section  on 
Retention,  is  employed  for  these  cases,  while  the  retention  of  canines 
and  incisors  is  the  same  as  that  described  in  the  latter  section,  and  in 
that  on  treatment  of  cases  of  the  first  class. 

Fig.  796  shows  the  ease  corrected  and  at  the  time  of  adjustment  of 
the  retaining  devices,  and  the  face  on  the  right  in  Fig.  622  shows  the 
result  of  treatment  on  the  facial  lines. 

The  case  here  shown  is  one  ])urposely  selected  as  being  not  only 
typical  but  also  of  unusual  difficulties,  owing  to  the  large  size  and 
density  of  the  jaws,  and  the  full  complement  of  unusually  large  teeth, 
all  of  which  were  in  mal-occlusion  and  required  to  be  moved  in  order 
to  carry  out  this  plan  of  treatment,  yet  the  mesial  movements  of  all  the 
lower  teeth  and  the  opposite  movement  of  the  upper  molars,  ])remolars, 
and  canines,  together  with  the   necessary  individual  movements  of  the 


TREATMENT. 


835 


incisors  and  canines,  were  effected  simultaneously  and  in  about  three 
months'  time. 

Of  course,  the  golden  time  for  the  treatment  of  this  case  was  at,  or 
soon  after,  the  time  of  the  eruption  of  the  first  molars,  and  the  difficul- 

FiG.  797. 


ties  of  treatment  have  gradually  increased  with  the  advance  of  years. 
It  is  quite  probable  that  all  that  would  have  been  necessary  at  that 
time  Avould  have  been  simply  the  directing  into  normal  relations  the 
first  molar  teeth. 

Fig.  798. 


Fig.  797  shows  the  mal-occlusion  of  another  case  from  both  right 
and  left  sides,  this  patient  being  much  younger,  but  the  treatment  being 
after  the  same  plan. 

Fig.  798  shows  the  facial  lines  of  the  patient  before  treatment,  and 
how  greatly  they  were  marred  by  the  pronounced  mal-occlusion. 


836 


ORTHODONTIA. 


Fig.  799  shows  the  ease  at  the  time  of  the  adjustment  of  the  retain- 
ing devices,  and  Fig.  800,  the  improvement  in  the  faeial  lines  at  this 
time. 

It  will  l)e  notieed   how  short  is  the  bite  in  the  incisive  retrion,  and 


Fm.  ::•••. 


^^^^^^S-i—^^i-isi^^si. 

^^^^^^^^^^^1 

1/' 

^H 

^B 

«^^i^^^H 

^M^-  •  ■,  •»'.":W-'il^  tf  jji ' 

'^1Ci^''i>.^  ^'iC^^^^^ 

this  gives  us  an  opportunity  to  point  out  the  importance  of  establishing 
the  normal  length  of  overbite,  and  while  this  condition  mav  be  met  in 
the  treatment  of  any  ca.se  of  any  class,  it  is,  as  Dr.  Kirk  has  well  said 


Fl.;.  SdO. 


"of  quite  as  much  importance  that  the  proper  length  of  bite  be  estab- 
lished, as  it  is  that  any  other  phase  of  raal-occlusion  be  corrected." 

AVhere  the    overbite    may  in   some  instances  be  due  to  the  supra- 
eruption  of  the  incisors,  it  will  in  most  instances  be  found  to  be  due  to 


.  TREATMENT.  837 

the  infra-eruption  of  the  first  molars,  and  usually  the  lowers.  Efforts 
have  been  made  from  time  to  time  to  elevate  the  lower  first  molars,  and 
where  this  is  easily  enough  accomplished,  the  great  length  of  time 
necessary  to  keep  these  teeth  suspended  in  their  sockets  until  the  peri- 
dental membrane,  especially  its  suspensory  fibres,  shall  have  become 
reorganized  to  maintain  tliem  in  this  position  against  the  force  of  the 
jaws,  makes  it,  in  the  writer's  opinion,  impracticable.  But  the  bite 
may  be  lengthened  in  a  very  simple  and  practical  way,  namel}§';through 
the  use  of  what  has  long  been  known  as  a  "  bite-plate,"  consisting  of  a 
vulcanite  plate  made  to  cover  the  vault  of  the  arch,  with  depressions 
in  its  anterior  labial  surface  to  receive  the  occlusal  edges  of  the  lower 
incisors,  thereby  preventing  the  molars  from  coming  in  contact,  and 
thus  relieving  them  of  all  pressure.  In  a  few  weeks  or  months  they 
will  have  elongated  sufficiently  to  lengthen  the  bite  the  amount  required. 

In  order  to  prevent  the  plate  from  being  displaced  and  the  incisors 
from  being  /forced  labially  as  the  thrust  of  the  lower  teeth  is  received 
against  the  plate,  spurs  of  platinized  gold  wire  should  be  vulcanized 
into  the  plate,  and  bent  to  engage  the  cutting  edges  of  the  upper  inci- 
sors, so  that  the  full  force  of  the  plate  will  be  received  on  the  edges  of 
the  upper  incisors  through  the  spurs. 

As  this  plate  may  be  easily  constructed,  it  should  be  promptly  made 
and  adjusted  in  every  case  where  its  use  is  indicated,  and  thereby 
effectually  overcome  a  defect  in  occlusion,  which,  if  not  remedied,  may 
tend  to  the  further  disarrangement  of  the  occlusion. 

It  may  be  well  to  note  that  in  nearly  all  cases  belonging  to  Class 
II.  there  is  more  or  less  of  an  abnormal  overbite,  sometimes  most  pro- 
nounced, but  it  is  gratifying  to  note  that  this  will  in  most  instances 
disappear  in  proportion  as  the  dental  apparatus  is  adjusted  to  normal 
occlusion. 

Class   II. — Division   2,  Subdivision. 

In  cases  belonging  to  this  subdivision  the  conditions  and  indications 
for  treatment  on  the  abnormal  side  are  similar  to  those  in  Division  2, 
Class  II.,  just  described,  the  differences  being,  like  those  of  the  sub- 
division of  Division  1,  Class  II.,  that  one  of  the  lateral  halves  of  the 
dental  Arches  only  is  in  distal  occlusion,  the  lower  first  molar  on  this 
side  failing  to  lock  normally,  but,  as  it  erupted,  was  shifted  into  distal 
occlusion,  necessitating  the  abnormal  locking  of  each  succeeding  tooth 
that  erupted,  until  we  have  inharmony  in  the  sizes  of  the  arches,  the 
upper  being  larger  to  the  extent  of  one  premolar  tooth,  and  the  com- 
pensation being  in  the  overlapping  of  the  upper  incisors  and  canines,  as 
shown  in  the  typical  case.  Fig.  801. 

The  treatment  clearly  indicated  was  the  correction  of  the  malposi- 


s;>8  oRruoDoy'TiA. 

tioii  of  each  tooth  in  rat-li  arch  ;  at  the  same  time  the  sizes  of  the  <h'Utal 
arches  were  made  to  harmonize  hy  the  movement  mesially  ol'  the  h)\ver 
teeth  on  the  abnormal  side  one-halt"  the  width  of  a  premolar,  wiiile  the 
upper  ineisors,  pri-molars,  and  eanines  were  heini^  shifted  distally  to  the 

V\r..  '<nl. 


|H 

1  _--    ^      Accijr   ^^^H 

^^H 

j^MKfr^-  \ 

*'''~iT 

■                         -^H 

^^^^ " "  ' 

"  'M 

If                     ^1 

^^H 

1 

H                               \y"t    li           ^^^^^ 

■HI 

same  extent  hv  the  nse  of  the  expansion  arc-hes,  D  bands,  ete.,  in  con- 
nection with  the  liaker  anchorage,  all  as  already  described.  The  result 
is  shown  in  Fig.  802.  * 

Fig.  <S()3  shows  the  facial  lines  before  treatment,  and  Fig.  804  shows 
how  they  have  been  modified  as  a  result  of  correcting  the  mal-occlusion. 
The  weak,  receding  under-lip  has  been  given  a  stronger  appearance,  and 


H||^^H| 

'*'      -■'B 

1    '                        .^     ^H 

H 

1  -"^W        fl 

3 

I          ^h^'-fifii.  ii  j^J 

almost  perfect  l)alance  of  the  mouth  with  the  rest  of  the  features  has 
been  established. 

A  former  plan  of  treatment  by  the  writer  for  these  cases  is  shown  in 
Fig.  695,  in  which  harmony  in  the  sizes  of  the  arches  was  established 
by  extracting  the  first  upper  premolar  on  the  abnormal  side  and  retract- 
ing the  canine,  and  at  the  same  time  the  incisors  and  canines  were 
rotated  into  correct  alignment. 


TREATMENT. 


839 


The  combination  of  the  traction-screw  and  expansion  arch,  wire  liga- 
tures, etc.,  are  all  well  shown,  and,  indeed,  this  is  one  of  the  most  thor- 
ouo-hly  efficient  devices  for  performing  tooth  movements  that  is  any- 
where found  in  the  history  of  orthodontia,  as  each  part  braces  and 
assists  reciprocally  the  other  parts  of  the  device  in  eifecting  the  various 
tooth  movements,  and  while  it  was  the  occasion  of  much  pride  with  the 
writer,  the  Baker  anchorage  has  made  its  use  unnecessary  in  nearly  all 
cases,  and  it  is,  therefore,  rarely,  if  ever,  required. 


FiG  80.3. 


Fig.  804. 


Class   III. 

In  the  treatment  of  cases  belonging  to  Class  III.  our  possibilities  for 
success,  more  than  in  any  other  orthodontic  work,  depend 
on  beginning  treatment  early. 

Be  it  remembered  that  this  deformity  begins  at  about 
the  age  of  the  eruption  of  the  first  permanent  molars, 
and  that  it  is  always  associated  at  this  age  with  enlarged 
tonsils,  and  the  habit  of  protruding  the  mandible  prob- 
ably in  some  way  affi)rds  some  relief  in  breathing,  which 
habit,  it  seems  reasonable  to  the  writer  to  believe,  is  a 
potent  factor  in  the  locking  of  the  first  permanent  molars, 
as  they  erupt,  into  mal-occlusion  (mesial  occlusion).  And 
when  once  the  mesio-buccal  cusp  of  the  upper  first  molar 
begins  to  engage  the  distal  incline  of  the  disto-buccal 
cusp  of  the  lower  first  molar,  the  result  mechanically  is  to  force  the 
mandible  forward  on  each  closure  of  the  jaws.  This  in  time  forces 
the   deciduous   teeth  into    mal-occlusion,   as   well    as    each    succeeding 


E.H.  A. 


.S4() 


onruoDoMiA. 


permanent  tooth  as  it  erupts,  thereby  enlisting  the  other  inelined  planes 
to  act  out  of  harmony  with  natnre's  intended  plan,  and  to  assist  in 
aecelerating  the  forward  movement  of  the  mandihie.  Not  oidv  tliis,  hut 
the  hour  is  thus  stimulated  to  develop  ahnormaily,  whieh  is  prcjbablv 
furthered  to  no  small  extent  by  the  added  stimulus  of  the  muscles  in 
tlu'ir  abnormal  relations  with  it. 

l'l(,.  so.'). 


So,  after  inharmony  is  once  established  and  the  lower  first  molars 
locked  in  mesial  occlusion,  the  progress  must  be  and  is  rapid,  only  a  few 
years  being  necessary  to  develop  by  far  the  worst  type  of  deformity 
the  orthodontist  is  called  upon  to  treat ;  and  when  the  case  has  pro- 
gressed until  the  age  of  perhaps  sixteen,  or  after  the  jaws  have  become 

Fig.  80G. 


developed  in  accordance  with  the  malpositions  of  the  teeth,  all  excepting 
the  third  molars  having  erupted  by  this  time,  the  case  has  passed  beyond 
the  boundaries  of  simple  mal-occlusion  and  into  that  realm  of  marked 
complications,  namely,  bone  deformities,  with  little  possibility,  with  our 
present  knowledge  of  the  subject,  of  our  affording  much  relief. 


TREATMENT. 


841 


It  is  the  writer's  firm  belief  that  if  these  oases  could  receive  prompt 
attention  at  the  important  period  of  the  eruption  of  the  first  molars,  the 


Fig.  807. 


throats  properly  treated,  and  the  first  molars  mechanically  assisted  into 
normal  occlusion,  and  there  compelled  to  remain  by  delicate  yet  efficient 


Fig.  808. 


retention  for  a  few  months,  these  unsightly  deformities  would  rarely, 
if  ever,  develop. 


842 


ORTHODONTIA. 


There  may  be,  aiul  (l()iil)tless  are,  other  factors  that  enter  into  the 
production  of  these  as  yet  but  imperfectly  understood  deformities ;  but 
we  are  convinced  that  they  are  of  minor  importance  to  those  we  have 
mentioned. 

The  time-honored  shifting  of  these  conditions  on  to   heredity  and 

Fk;.  sou. 


suj)p()sed    degenerate    tendencies    no    h)nger   satisfies    or    carries    much 
weight. 

Figs.  805  and  80G  show  the  mal-occlusion  in  the  case  of  a  ehikl  six 
years  of  age,  who  was,  and  liad  been  for  some  time,  a  sufferer  from  greatly 
enlarged  tonsils.     It  will  be  seen  that  the  first  molars  are  erupting,  and 

Fui.  810. 


that  the  lowers,  in  taking  their  positions,  will  .■^oon  become  locked  in 
mesial  occlusion.  This  is  a  fair  example  of  the  beginning  of  all  these 
cases. 

It  will  be  seen  that  the  deciduous  teeth  are  rapidly  becoming  har- 
moniz.ed  to  the  abnormal   occlusion,  the  lower  incisors  now  closing  iu 


TREATMENT. 


843 


front  of  the  upper  incisors.  Thus  the  tendency  is  clearly  indicated  and 
its  effects  shown  on  the  facial  lines  (Figs.  807  and  808),  and  this  con- 
dition has  developed  rapidly,  the  contour  of  the  baby  face  being  thus 
changed  in  but  a  few  weeks. 

The  treatment  was  simple  and  easy.     Small  D  bands  were  placed 

Fig.  811. 


upon  all  four  deciduous  second  molars  and  the  plain  expansion  arches 
were  adjusted,  as  per  combination  shown  in  Fig.  688,  and  the  force 
exerted  by  means  of  the  delicate  rubber  ligatures  made  to  engage  the 
sheath-hooks  on  the  lower  arch,  which  were  placed  well   forward,  or 


Fig.  812. 


opposite  the  lateral  incisors,  and  the  other  ends  stretched  over  the  distal 
ends  of  the  sheaths  of  the  upper  anchor-bands,  the  result  being  that  in 
a  very  short  time  the  teeth  were  shifted  into  normal  relations. 

The  case  was  retained  by  means  of  two  delicate  spurs  soldered  to  the 


844 


ORTHODOSTTA. 


lingual  surfaw  of  «lclic':itc  l):iii(ls  mi  the  upper  (Icciduoiis  central  inci- 
sors, these  spurs  cxtendinii;  tlow  iiward  and  somewhat  forward  in  front  of 
the  lower  ceutrals,  thus  c()Uii)rlling  the  iionnal  closure  of  the  numdihle, 
and  Figs.  80i>  and  SIO  show  the  occlusion  at  this  stage,  the  lower  decid- 
uous laterals  nieautinie  having  been  lost.     The  pronounced  change  in 

Fi.;.  Sl.S. 


the  facial  lines  as  the  result  of  this  modified  occlusion  is  shown  in  Fig. 
811. 

The  eruption  and  locking  of  the  first  permanent  molars  was  now  com- 
plete, and  the  deciduous  upper  incisors,  which  with  their  retaining  bands 


Fig.  814. 


EH  A 


and  spurs,  were  lost  through  the  natural  absorption  of  their  roots  a  few 
weeks  later,  and,  although  a  year  has  since  elapsed,  the  molars  still 
occlude  in  normal  relations,  and  the  development  of  the  face,  jaws,  and 
teeth  continues  to  progress  normally  and  in  a  most  gratifying  manner. 


TEE  A  TMENT. 


845 


Fig.  812  shows  the  mal-occlusion  in  another  case  of  a  patient  some- 
what older,  in  which  the  natural  progress  of  the  deformity  is  clearly 
shown.  The  patient  is  thirteen  years  old,  and,  following  the  abnormal 
locking  of  the  first  permanent  molars,  all  of  the  teeth  anterior  thereto 
have,  as  they  erupted,  been  forced  to  take  positions  of  mal-occlu- 
sion. 

The  result  in  the  inharmony  of  facial  lines  is  shown  in  Fig.  623. 

The  treatment  clearly  indicated  was  to  establish  harmony  in  the  sizes 
of  the  arches  and  normal  relations  of  the  inclined  planes,  if  possible. 
Without  the  Baker  anchorage  this  would  have  been  impossible,  but  with 
it  the  desired  changes  were  effected,  and  that,  too,  quite  speedily. 

Fig.  815. 


The  same  combination  of  appliances  as  that  described  for  the  last 
case  was  also  used  in  this.  The  force  necessary  to  shift  mesially  the 
upper  teeth  was  reciprocated  to  move  distally  all  of  the  lower  teeth.  It 
is  quite  probable  that  the  mandible  was  also  moved  distally  somewhat. 
In  fact,  this  is  shown  in  the  facial  lines  after  treatment  (Fig.  624),  but 
the  principal  change  was  in  the  positions  of  the  crowns  of  the  teeth 
after  three  weeks'  treatment,  shown  in  Fig.  813. 

No  effort  was  made  to  establish  better  relations  between  the  pre- 
molars, knowing  full  well  that  as  these  teeth  continued  their  eruption 


S4<) 


ORTHODOSTIA. 


tlu'v  would  he  torccd  more  and  niori'  into  tlicir  iKtnnal  ivlatioiis  tlinuigh 
the  infliKMice  of  their  inclined  occlusal  planes. 

The  retention  was  etreeted  In'  means  of  the  device  shown  in  Fig. 
789,  and  already  described,  in  connection  with  molar  retention,  in  the 
first  division  of  Class  II.,  the  difference  being  that  the  spur  was  made 
to  close  behind  the  metal  plane  in  this  case,  instead  of  in  front  of  it,  as 
in  Class  II.  cases,  thns  reversing  its  action. 

Any  purely  orthodontic  treatment  in. such  j)roiionnce<l  cases  as  that 
shown  in  Fig.  814  (facial  lines  in  Fig.  815)  is  a  waste  of  time  both  of 
patient  and  operator.  The  only  possible  relief  would  be  by  perl'orming 
the  writer's  operation  known  as  "double-resection  of  the  jaw,'"  but  as 
that  comes  under  the  realm  of  surgery,  its  consideration  does  not  prop- 
erly belong  here. 

Via.  -SI 6. 


Even  in  sucli  cases  as  that  shown  in  Fig.  81(j,  where  the  mal-oeclu- 
sion  has  never  ])assed  beyond  siin])le  mesial  occlusion,  yet  at  this  age  of 
the  patient  (twenty -five  years)  the  jaws  and  muscles  have  become  fixed 
in  their  abnormal  development,  and  the  result,  after  many  months  of 
l)atient,  persistent  treatment,  will  usually  be  found  to  be  most  discour- 
aging and  unsatisfactory.     They  are  good  cases  to  avoid. 

AVe  have  elsewhere  given  our  views  relative  to  the  use  of  the  chin 
retractor  and  occijntal  anchorage  in  connection  with  the  treatment  of 
these  cases,  and  how  they  have  practically  become  superseded  by  the 
Baker  anchorage.  The  writer  no  longer  finds  value  in  their  use,  although 
there  is  the  barest  possibility  that  they  may  still  in  some  instances  have 
use  as  an  auxiliary  to  the  Baker  anchorage. 


'  For  the  consideration  of  this  operation  we  would  refer  to  the  writer's  Md-ocelmion 
of  the  Teeth  and  Fracture,<i  of  the  MaxillcF,  sixth  edition. 


TREATMENT.  847 


Class  III. — Subdivision. 


As  cases  belonging  to  the  subdivision  of  Class  III.  are  in  unilateral 
mesial  occlusion,  the  treatment  clearly  indicated,  especially  in  young 
patients,  is  after  the  same  plan  we  have  already  described  for  the  full 
division,  exerting  force,  however,  only  on  the  side  that  is  in  mesial 
occlusion. 

The  writer  has  aimed  to  point  out  a  simple  yet  efficient,  as  well  as 
logical,  way  not  only  of  diagnosing  mal-occlusion,  but  also  its  treat- 
ment, from  the  simplest  to  the  most  complex  cases — and  all  from  the 
basis  of  normal  occlusion,  the  demands  of  which  necessitate  the  full 
complement  of  teeth,  therefore  no  mention  has  been  made  of  a  neces- 
sity for  the  voluntary  sacrifice  of  teeth. 

Doubtless  extraction  may  sometimes  be  necessary,  but  being  a  prac- 
tice that  is  illogical,  unnatural,  and  necessary  only  in  such  rare  instances, 
it  is  impossible  to  lay  down  any  rules  for  the  intelligent  guidance  of  the 
operator  as  to  when  extraction  should  be  resorted  to.  His  judgment 
must  determine  this  point. 

The  writer  can  conceive  of  but  three  conditions  under  which  extrac- 
tion might  be  permissible  : 

First,  in  the  case  of  the  arrest  in  the  development  of  the  alveolar 
process  in  patients  of  advanced  years,  or  at  a  period  when  nature  would 
not  be  stimulated  to  complete  the  development  of  the  alveolar  process 
and  intermaxillary  bones  even  though  the  teeth  were  placed  in  correct 
relations,  as  we  have  already  pointed  out  that  she  does  do  most  gener- 
ously in  young  patients. 

At  just  what  period  the  growth  of  the  intermaxillary  bones  and  their 
alveolar  process  ceases,  or  nearly  ceases,  to  develop  is  as  yet  not  known. 
It  is  probable,  generally  speaking,  that  this  period  practically  ends  not 
long  after  the  complete  eruption  and  development  of  the  canine  teeth. 
But  we  repeat  that,  even  at  this  age,  only  in  extreme  cases  will  it  be 
found  that  the  lack  of  development  is  so  great  as  to  make  extraction 
advisable  in  order  to  keep  the  teeth  in  the  line  of  occlusion  without  the 
aid  of  permanent  mechanical  retention. 

Second,  extraction  of  a  tooth  in  one  dental  arch  might  be  permissible 
to  compensate  for  the  loss  of  teeth  in  the  opposite  arch,  yet,  while  such 
procedure  may  in  some  instances  be  permissible,  we  do  not  believe  the 
plan  will  ever  be  a  favorite  method  with  the  best  practitioners  of  ortho- 
dontia, as  it  creates  one  deformity  because  another  exists,  and  because 
the  facial  lines  are  impaired  instead  of  improved  in  consequence. 

As  a  rule,  it  cannot  be  argued  that  this  is  an  easier  and  quicker 
method  of  establishing  comparative  harmony,  for  we  believe  that  correc- 
tion according  to  the  demands  of  normal  occlusion  is  easier :  that  is,  to 


848  ORTHODONTIA. 

regiiiii  space  and  suhstituto  the  missing  tooth  or  toeth  artificially.  Tli«* 
advantage  to  the  facial  lines  and  to  the  voice  of  the  latter  plan  has  else- 
where been  fnlly  discussed. 

Lastly,  though  it  is  hardly  necessary  to  nuntion  it,  for  the  removal 
of  supernnmerary  teeth.    • 

Finally,  orthodontia  shonld  be  taught  and  j)nictised  as  a  distinct 
specialty,  for  there  is  no  specialty  in  medicine  with  more  clearly  defined 
boundary  lines,  and  only  after  much  .study  and  practice  will  even  those 
with  aptitude  and  liking  for  the  branch  ever  be  competent  to  successfully 
practise  it.  To  those  is  offered  a  rich  field,  but  to  the  mere  smatterer 
orthodontia  will  never  bring  anything  but  discouragement  and  failure. 


CHAPTER    XXV. 

THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

By  Calvin  S.  Case,  D.  D.  S.,  M.  D. 


I.  Influence  of  the  Teeth  on  the  Physiognomy. 

In  the  developmental  processes  of  animal  life  the  teeth  have  proba- 
bly been  more  influential  than  any  of  the  other  organs  in  shaping  the 
bones  of  the  head — especially  in  determining  the  physical  characteristics 
of  the  physiognomy.  The  physical  shape  and  structure  of  the  jaws 
conclusively  show  the  influence  that  the  teeth  have  exerted  in  different 
species  in  response  to  Nature's  law  to  propagate  that  ^vhich  would  })est 
subserve  them  in  the  performance  of  their  functions.  The  importance 
of  the  teeth,  therefore,  and  their  inherent  demand  upon  surrounding 
anatomical  structures  for  proper  means  of  development,  sustenance,  and 
use,  is  evidence  that  they  exert,  during  development,  a  more  or  less  im- 
mediate influence  in  determining  the  size  and  shape  of  the  maxillary 
bones,  and  thus  indirectly  are  extensively  influential  in  characterizing 
the  individual  shape  of  the  human  face. 

Often  the  position  of  the  anterior  teeth  and  alveolar  process  is  such 
as  to  impress  upon  the  contiguous  features,  even  in  repose,  certain  con- 
ditions which  vary  from  a  slight  imperfection  in  esthetic  contour  to  a 
most  distressing  facial  deformity.  Nor  are  these  dento-facial  imperfec- 
tions always  wholly  due  to  a  malposition  of  the  teeth,  so  much  as  to  a 
lack  of  normal  symmetry  in  the  size  or  shape  of  the  maxillary  bones 
upon  which  so  large  an  area  of  the  face  is  dependent  for  its  contour. 
These  conditions  may  have  arisen  from  the  direct  inheritance  of  a 
parental  deformity,  or  from  the  inharmonious  union  of  unaltered  types, 
as  the  teeth  of  one  parent  and  the  jaws  of  another.  It  is  equally  true 
that  the  union  of  harmonious  types  often  results  in  symmetrical  condi- 
tions which  neither  parent  possesses. 

Among  local  causes,  or  those  which  operate  after  birth  in  the  pro- 
duction of  facial  imperfections,  may  be  mentioned  habits,  impaired 
dentition,  delayed  and  injudicious  extraction  of  the  deciduous  teeth  or 
first  permanent  molars,  and  mal-occlusion. 

The  influence  of  the  teeth  during  the  time  of  their  eruption  (produ- 

54  849 


850       THE  DEVKLOPMEyT  OF  ESTHETIC  FACIAL   CONTOURS. 

cing  on  tho  oiii"  hand  i\\v  excessive  pressnre  of"  large  teeth  and  concomi- 
tant alveolar  development,  and  on  the  other  a  lack  of  pressure  from  an 
irregnlarity  or  injndicions  extraction)  in  etVecting  a  change  in  the  in- 
herent shape  or  size  of  the  maxillary  bones  beyond  that  which  the 
alveolar  process  is  forced  to  assume  to  accommodate  them,  has  been  a 
(piestion  of  considerable  controversy.  It  is  reasonable  to  assiune,  how- 
ever, that  natural  inHuences  exerting  a  slight  force  u])on  the  immature 
maxillary  or  other  bones,  during  early  stages  of  their  growth,  would 


KiG.  SI 7. 


Fio.  SIS. 


Fig.  81 '.I. 


have  somewhat  the  same  effect  that  is  known  to  be  possible  later  by 
artificial  force. 

The  following  case  will  serve  to  illustrate  this  principle  : 
Patient  aged  thirteen  years.     When  presented  the  upper  incisors 

were  fully  the  width  of  a  tooth  posterior 
to  a  normal  j)()sition,  and  so  badly  in- 
locked,  in  occlusion,  that  the  crowns  were 
nearly  hidden  behind  the  lower.  (See 
Fig.  817.)  With  the  exception  of  the 
II j)per  canines,  which  were  forced  slightly 
(Uit  of  alignment,  all  the  other  teeth  in 
l)oth  jaws  were  in  proper  position  and 
occlusion.  (See  Fig.  818.)  The  posterior 
position  of  the  inlocked  incisors  was  not 
due,  in  the  slightest  degree,  to  a  lingual 
inclination  of  their  crowns,  but  the  re- 
trusion  extended  to  the  roots  as  well 
and  seemed  to  involve  the  intermaxil- 
lary process,  producing  a  decided  depression  of  the  overlying  features. 
(See  Fig.  819.; 

The  probable  history  of  the  cause  of  this  condition  is  as  follows : 
The  lower  incisors  erupted  much  earlier  than  the  upper,  and  there  being 


INFLUENCE  OF  THE  TEETH  ON  THE  PHYSIOGNOMY.        851 

a  short-bite  occlusion,  as  soon  as  the  upper  incisors  began  to  erupt  they 
became  inlocked  with  the  lower  incisors.  At  this  time  the  roots  and 
surrounding  processes  were  in  an  immature  condition.  As  the  crowns 
continued  to  erupt  they  slid  down  the  posterior  faces  of  the  lower  in- 
cisors, where  they  were  retained  during  the  continued  development  of 
the  roots  in  the  opposite  direction,  the  force  being  sufficient  to  prevent 
the  natural  growth  and  development  of  the  entire  intermaxillary  process, 
which  normally  would  have  carried  them  bodily  forward  to  an  harmo- 

FiG.  820. 


(Before.)  (After.) 

nious  position.  As  the  otner  teeth  came  into  place  the  lateral  portions 
of  the  jaw  were  allowed  to  normally  develop  in  harmony  with  the  natural 
growth  of  the  other  parts.  Thus  the  canines  and  bicuspids  were  found 
in  their  proper  relative  positions  as  regards  the  lower. 

Fig.  821.  Fig.  822. 


Force  was  applied  with  the  contouring  apparatus  described  in  section 
VI.  of  this  chapter.  In  less  than  six  months  the  incisors  were  carried 
bodily  forward  i-ii  an  upright  position,  together  with  the  entire  surround- 
ing alveolar  ridge  and  intermaxillary  process  (see  Figs.  820  and  821), 


852       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 


Fig.  823. 


witli  a  perfect  correction  of  a  very  unlia|)})v  facial  deforniity.  (See 
Fig.  822.)  Fig.  823  is  from  a  photograph  taken  three  years  after  the 
completion  of  the  operation. 

In  dental  orthopedia  we  possess  the  great  advantage  over  general 

orthopedia  of  applying  force  directly 
to  the  bone  itself,  through  the  medium 
of  the  teeth,  without  the  intervention 
of  the  soft  and  sensitive  tissues. 

The  teeth  imbedded  in  the  alveolar 
process,  that  in  turn  is  firmly  united  to 
the  true  bone,  may  be  considered,  when 
in  the  grasp  of  a  regulating  machine, 
as  an  integral  part  of  it,  firmly  and  di- 
rectly attached  to  that  part  of  the  bone 
we  desire  to  move,  and  capable  of 
exerting  the  quality  and  direction  of 
force  the  machine  gives  to  them. 
This  force  being  applied  unitedly  to  a  number  of  teeth  standing  side 
by  side,  the  surrounding  and  contiguous  bone — which  is  largely  a  can- 
cellated structure — is  carried  bodily  in  the  direction  of  the  force  ;  not 
by  the  fracture  of  its  substance  or  to  any  great  extent  by  a  metamor- 
phosis of  tissue,  but  by  the  bending,  condensation  and  elongation  of  its 
cellular  structure  ;  the  whole  adapting  itself  to  a  new  form,  in  which 
position  the  immediate  interstitial  tension  of  its  j)articles  is  soon  relieved 
and  brought  to  equilibrium  by  Nature  —though  it  may  require  to  be 
held  in  that  position  for  many  months  before  there  is  an  entire  relief 
from  the  inherent  tendency  to  return  to  the  primary  position. 

In  contemplating  the  treatment  of  a  dental  irregularity  a  careful 
study  of  the  physiognomy  in  different  attitudes  of  expression  should  be 
made,  with  the  view  of  determining  the  relative  position  of  teeth  and 
facial  contours.  The  value  of  a  careful  preliminary  facial  examination 
and  comparison  cannot  be  overestimated,  for  it  is  often  the  only  guide 
to  correct  treatment. 

For  instance,  since  it  has  become  possible  to  expand  or  retract  the 
anterior  portion  of  the  upper  apical  zone  with  the  surrounding  bone  in 
which  the  moving  roots  are  imbedded,  we  are  no  longer  confined  to  the 
possibility,  and  frequent  questionable  propriety,  of  permanently  moving 
the  lower  jaw  forward  or  backward  to  correct  a  facial  deformity  which 
pertains  exclusively  to  the  upper  maxillae  and  middle  features  of  the 
face. 


PRINCIPLES   OF  FACIAL   ORTHOPEBIA. 


853 


n.  Principles  of  Facial  Orthopedia. 

The  portion  of  the  human  face  that  it  is  possible  to  change  with  a 
dental  regulating  apparatus  may  be  said  to  lie  between  two  diverging 
lines  which  arise  at  a  point  below  the  ridge  of  the  nose  and  curve  down- 
ward to  inclose  the  alse  and  depressions  on  either  side ;  thence  laterally 
to  encircle  a  portion  of  the  cheek,  and  downward  to  inclose  the  entire 
chin.     (See  Fig.  824.) 

Within  this  ovoidal  area  the  slightest  change  of  muscular  movement 
expressive  of  the  emotions  Mill  produce  an  apparently  marked  effect 
upon  the  entire  physiognomy.  The  same  is  true  of  any  physical  imper- 
fection of  contour,  particularly  around  the  mouth.  It  is  here  that  an 
inherited  or  acquired  lack  of  symmetry  in  the  size,  shape,  or  position  of 
the  teeth  and  jaws  produces  those  marked  changes  of  facial  contour  which 
characterize  the  several  classes  of  dento-facial  deformities.  This  area 
may  be  termed  the  "  changeable  area  "  in  contradistinction  to  the  more 
stable  features,  or  "  unchangeable  area." 

For  convenience  of  ready  reference,  the  features  in  that  portion  of 
the  changeable  area  which  are  bounded  laterally  by  the  naso-labial  lines 
may  be  divided  into  four  segments  as  follows  : 

Segment  1. — The  end  of  the  nose  and  the  upper  portion  of  the  upper 
lip,  including  the  naso-labial  depressions. 


Fig.  824. 


Unchangeable  area  ^ 


Changeable  area  • 


Segment  2. — The  lower  portion  of  the  upper  lip. 
Segment  3. — The  lower  lip. 
Segment  If. — The  chin. 


H54       TIIF.    DEVELoi'MESr  OF  ESTHETIC  FACIAL   CONTOURS. 

In  the  proliminaiv  examination  oi"  the  physiognuniy  from  a  purely 
esthetic  standpoint  with  a  view  of  correcting  a  ilento-facial  deformity 
or  imperfection  by  applying  force  to  the  teeth,  there  are  certain  promi- 
nent features  to  be  especially  observed  and  their  relative  position  care- 
fully noted.  These  may  be  divided  into  two  class(\s  :  first,  those  which 
lie  in  the  unchangeable  area,  as  the  forehead,  bridge  of  the  nose,  and 
malar  prominences;  second,  those  in  the  changeable  area. 

The  four  segments  in  the  latter  class  shown  in  b'ig.  824  are  change- 
able in  their  relations  to  each  other,  and  also  in  their  individual  relation 
to  features  in  the  unchangeable  area.  For  instance,  it  is  possible  to  pro- 
trude or  retrude  the  upper  portion  of  the  upper  lip  with  the  depressions 
on  each  side  of  the  nose,  the  nasal  septum,  and  the  end  of  the  nose, 
without  changing  the  lower  portion  of  the  upper  lip  in  its  relation  to 
other  parts.  (See  Fig.  833.)  The  same  is  true  of  the  other  segments 
— in  fact,  a  retrusion  of  the  second  segment  and  a  protrusion  of 
the  first  may  be  accomplished  at  the  same  time.  (S(c  Figs.  831 
and  832.) 

If  the  lower  jaw  be  mechanically  ])r()trnde(l  or  retruded  bodily,  the 
lower  lip  will  of  necessity  be  carried  forward  or  backward  with  the 
chin,  unless  a  special  operation  is  performed  on  the  lower  teeth  to  pre- 
vent it  from  changing  its  relations  to  the  upper  lij). 

Those  portions  of  the  changeable  area  which  lie  over  the  bicus- 
pids and  first  molars — shown  in  Fig.  824 — and  separated  from  the  lips 
by  the  naso-labial  lines,  may  be  considered  as  separate  segments,  as  the 
causes  which  influence  a  change  in  the  contour  of  the  cheeks  differ  so 
decidedly  from  those  which  change  the  more  anterior  areas.  The  lateral 
expansion  or  contraction  of  the  dental  arches  will  often  change  the  con- 
tour of  the  cheeks  with  no  effect  upon  the  labial  area,  if  the  anterior 
teeth  remain  unchanged  in  position.  Again,  a  decided  retrusion  of  the 
anterior  teeth  and  process  with  no  lateral  expansion  of  the  arch  will 
invariably  result  in  giving  to  the  cheeks  a  fuller  contour,  by  relieving 
the  tension  of  muscular  tissues.  The  .same  result  will  often  be  obtained 
in  closing  the  characteristic  op?n  bite  of  a  niouth-breather  by  grinding 
the  posterior  teeth,  and    also  by  retracting  a   |)rognathous  lower  jaw. 

In  a  study  of  profiles  we  frequently  observe  a  lack  (»f  perfect  har- 
mony in  the  position  of  the  chin.  The  lower  jaw  is  apparently 
protruded,  or  retruded,  so  as  to  mar  the  esthetic  perfection  of  the 
physiognomy,  and  yet  were  these  same  faces  examined  l)y  a  trained 
observer  he  would  find  in  a  large  proportion  the  lower  jaw  in  ])erfect 
harmony  with  the  unchangeable  area,  and  that  the  appearance  of  its 
malposition  was  an  effect  due  wholly  to  a  protrusion  or  retrusion  of  the 
upper  jaw  and  teeth.  In  other  words,  it  is  a  common  error  to  imagine 
the  chin  imperfectly  posed  because  it  is  not  in  harmonious  relations  to 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS.  855 

the  other  features  of  the  changeable  area,  instead  of  comparing  it, 
as  we  should  do,  to  the  more  stable  or  unchangeable  features  of  the 
physiognomy. 

In  examining  the  physiognomy  of  a  patient,  the  head  should  be  in 
an  upright  position,  on  a  line  with  that  of  the  observer,  and  the  face 
studied  from  different  angles  while  in  repose  and  in  action. 

While  looking  at  the  profile  in  repose  the  most  important  thing  to 
determine  is  the  relative  position  of  the  chin  with  the  forehead,  malar 
prominences,  and  bridge  of  the  nose.  If  its  position  is  harmonious 
with  the  unchangeable  area  and  the  lower  lip  is  well  posed,  it  indicates 
that  the  operation  of  facial  contouring  should  be  performed — if  any- 
where— upon  the  upper  jaw  and  teeth.  For  if  the  first  and  second  seg- 
ments are  abnormally  protruded  it  will  cause  a  chin  to  appear  retruded 
that  is  perfectly  harmonious  in  its  relations  to  the  principal  features  of  the 
face.  (See  Fig.  825.)  Again,  a  retruded  or  contruded  upper  arch  with 
a  depression  of  those  features  which  are  supported  by  the  upper  maxillae 
will  cause  a  perfectly  posed  lower  jaw  and  chin  to  appear  protruded  or 
prognathous  ;  as  instanced  by  the  cases  illustrated  in  sections  I.  and  IV. 
in  which  the  facial  effect,  before  treatment,  was  that  of  protruded  lower 
jaw,  but  which  were  perfectly  corrected  by  an  anterior  movement  of 
the  upper  incisors  and  intermaxillary  processes. 

m.  Upper  Dental  and  Maxillary  Protrusions. 

Figs.  847  and  848  will  serve  to  illustrate  the  class  of  facial  de- 
formities known  as  abnormal  upper  protrusions,  and  the  advantage  of 
retruding  the  upper  anterior  teeth  and  surrounding  process. 

Fig.  825. 


In  Fig.  825  wide  interdental  spaces  between  the  upper  teeth  per- 
mitted the  reduction  without  extracting.  In  Fig.  826  the  upper  first 
bicuspids  were  extracted. 


850       THE  DF.VELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

If  the  openitioii  of  "jumping  tlu'  bite"  wore  performed  in  these 
cases,  there  wouhl  no  doubt  be  an  improvement  of  the  original  appear- 
ance of  tlie  j^hvsiognomv,  by  tlie  bringing  of  the  chin  and  lower  lip 
into  more  perfect  harmony  with  the  upper;  but  this  would  not  be  cor- 
rect treatment,  because,  as   will   be  observed,  the  chin    is   in    not   far 

Fio.  S2(). 


from  ])erfect  position  when  comjiarcd   with  other  features  of  the  un- 
changeable area. 

The   principles   involved   in   the  correction   of   this  class  of  facial 
deformities  niav  be  diagranimatically  illustrated  as  follows  : 

Fi...  -:J7.  Fi'..  >^-'^. 


Fig.  827  is  a  profile  view  of  a  typical  case  of  abnormally  protruded 
upjK'r  jaw.      It  will  be  observcil  that  the  chin  appears  retracted. 

FiiT.  828   shows   the   improved   effect  that    would   be   })roduced   by 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS. 


857 


"jumping  the  bite"  in  bringing  segments  3  and  4  into  more  perfect 
harmony  with  segments  1  and  2 ;  yet  not  to  be  compared  with  that  per- 
fection of  symmetrical  contour  shown  by  Fig.  829,  where  the  chin  and 
lower  lip  are  permitted  to  remain  in  their  original  harmonious  position 
while  the  end  of  the  nose  and  upper  lip  are  retruded  into  harmony  with 
the  whole. 

The  three  faces  have  been  made  exactly  alike  with  the  exception — 
as  shown  by  the  cross  lines — of  certain  mechanical  movements  of  the 
profile  outlines  in  the  changeable  area.  In  Fig.  828  the  outlines  of 
segments  3  and  4  are  forced  farther  forward,  and  in  Fig.  829  segments 


Fig.  830. 


1  and  2  are  carried  back  as  they  would  be  by  a  retruding  apparatus 
attached  to  the  teeth. 

In  comparing  Figs.  827  and  829  the  difference  in  esthetic  effect  is 
quite  striking,  and  it  is  one  also  which  would  seem  to  be  hardly  possible 
with  so  little  change  in  the  outlines  of  a  comparatively  small  area.  By 
cutting  a  piece  of  black  paper  to  the  exact  outlines  of  Fig.  829  and 
placing  it  upon  Fig.  827  the  real  and  only  difference  in  the  two  figures 
can  be  plainly  seen — as  in  Fig.  830. 

When  such  a  change  is  produced  in  the  features  of  a  human  face  the 
difference  is  greatly  enhanced  because  of  the  harmonious  perfection  of 
other  contours  not  shown  by  the  figures. 

It  is  a  noteworthy  fact  that  a  very  little  change  in  the  peripheral 
shape  or  position  of  certain  bones  of  the  face  on  which  the  features  are 
dependent  for  their  character  and  form— a  change  so  trifling  that  it  could 


858       THE  DEVKI.OPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

hardly  be  measured — resnltiii<:;  in  a  slight  filling  out  or  depression  of 
certain  contours,  will  often  beautify  to  a  remarkable  degree  the  ap- 
pearance of  a  face  that  would  otherwise  be  quite  plain  and  unattractive. 

This  is  true  of  all  the  more  common  cases  of  upper  protrusion  and 
retrusion  which  show  an  abnormal  prominence  or  depression  along  tlie 
upper  as  well  as  the  lower  j)ortion  of  tlie  upper  lip,  and  especially  of 
those  which  seem  to  involve  the  entire  intermaxillary  j)rocess,  influ- 
encing the  anteroposterior  position  of  the  wings  and  end  of  the  nose. 

In  cases  of  protrusion,  by  applying  a  retracting  force  especially 
dir<!cted  to  the  roots  and  crowns  of  the  anterior  teeth,  the  surrounding 
alveolar  process  and  anterior  portion  of  the  maxillae  will  be  forced 
back,  allowing  the  upper  lip  to  fall  into  a  more  graceful  and  easy  pose, 
leaving  the  nostrils  less  broad  and  open,  the  upward  curve  of  the  nose 
straightened,  and  its  pug-like  ap})oarance  removed. 

When  an  upper  protrusion  is  due  alone  to  a  labial  inclination  of 
large  crowded  teeth,  with  no  marked  protrusion  over  the  apical  zone,  or 
in  segment  1,  the  extraction  of  the  first  or  second  bicuspids  is  indicated, 
and  the  application  of  force  to  the  crowns  at  such  points  and  in  such 
direction  as  will  best  overcome  the  malj)()sition. 

Many  instances  have  arisen,  in  the  i)ractice  of  dentists  who  were 
opposed  to  the  extraction  of  teeth,  where  the  above  condition  has 
actually  been  produced  in  the  operation  of  crowding  irregular  teeth  into 
alignment  that  were  too  large  for  an  already  perfectly  harmonious 
maxillary  arch.     (See  Figs.   853  to  856    inclusive,  in  section  V.) 

There  are  innumerable  instances  where  a  labial  inclination  of  both 
the  upper  and  lower  anterior  teeth  produces  a  pronounced  protrusion  of 
the  lips  Avith  a  very  unpleasant  expression  in  their  management,  espe- 
cially if  in  occlusion  the  lower  anterior  teeth  are  even  with,  or  in  front 
of,  the  uppers.  The  fact  that  the  most  natural  occluding  position  of 
the  lower  front  teeth  is  somewhat  j)osterior  to  the  upper  teeth  permits 
the  graceful  curve  of  th(>  lower  lip  which  is  so  necessary  to  the  esthetic 
perfection  of  the  chin. 

In  order  to  correct  a  pronounced  facial  deformity  of  this  character 
})roduced  by  large  teeth  crowded  into  arches  that  are  too  small  for  them, 
but  (►therwisc  harmonious  in  size,  it  will  often  be  necessary  to  extract  a 
bicuspid  from  each  side  from  both  the  upper  and  lower  jaws.  Some- 
times the  extraction  from  the  lower  of  a  central  incisor  will  be  suf- 
ficient. 

Instances  frequently  arise  where  the  position  and  labial  inclination 
of  the  upper  anterior  teeth  produce  a  relative  protrusion  of  the  incisal 
zone  and  a  contrusion  of  the  a))ical,  with  a  protrusion  of  the  lower 
portion  of  the  upper  lip  and  a  slight  depression  of  the  upper  portion, 
deepening  the  naso-labial  depressions.     If  the  depression  of  segment  1 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS.  859 

be  not  too  pronounced,  it  may  be  restored  by  a  slight  forward  movement 
of  the  anterior  apical  zone,  accomplished  in  the  retrusion  of  the  incisal 
zone — by  force  applied  at  the  incisal  ends  of  the  teeth  alone,  with  the 
view  of  producing,  as  far  as  possible,  a  fulcrum  force  at  the  lingual 
margins  of  the  alveoli. 

If  the    malformation   is   produced    by  an    inharmonious   union   of 

Fig.  831. 


maxillse  and  teeth,  as  in  the  former  case,  the  extraction  of  an  upper 
bicuspid  from  each  side  will  be  indicated.  Figs.  831  and  832  were  made 
from  the  models  of  a  case  of  this  character,  before  and  after  treatment. 
The  upper  first  bicuspids  had  been  extracted  some  time  before  the 
patient  presented  for  treatment. 

In   contradistinction  to   this  class   of  deformities,  there   is  another 

Fig.  8.32. 


quite  as  common — though  not  so  frequently  recognized  as  an  abnor- 
mality— in  which  all  the  conditions  are  reversed,  in  that  the  teeth  have 
a  lingual  inclination  with  protrusion  of  the  apical  zone  and  maxillse. 

The  teeth  of  these  cases  are  commonly  regular  in  alignment,  and 
owing  to  their  lingual  inclination  the  occlusal  zone  may  be  in  proper 
relative  position.     (See  Fig.  833.) 


860     Till-:  j>/:\j:ij)1'm/:.\t  of  esthetic  facial  contours. 

The  facial  iiMju'i'lcctidii  Avliidi  consists  principally  in  a  prominence 
or  bulging  along  the  higher  portions  of"  the  upper  lip  and  in  the  region 
of  the  nasal  ahe  is  often  (piitc  pronounced.  When  this  is  caused  partly 
by  the  canine  roots  the  ditlicultics  are  much  increased  in  the  case  of 
patients  older  than  thirteen.  The  fact  that  the  roots  of  the  canines  are 
surrounded  by  the  most  dense  portion  (tf  the  alveolar  ]irocess,  and  their 
movement  bodily  in  a  posterior  direction  requiring  the  resorption  of  a 
large  portion  of  bone,  makes  this  operation  one  of  the  most  difficult  in 
dental  orthopedia. 

Fig.  833   is  from  the  models  of  a  })atient  over  tventv  vears  of  age, 

Fk;.  «;^r:. 


and  will  serve  to  illustrate  a  case  before  and  after  treatment  of  abnormal 
protrusion  of  the  roots  of  the  upper  anterior  teeth,  alveolar  process  and 
maxillte — the  axis  of  the  incisors  being  inclined  lingually. 

It  will  be  observed  that  the  canines  have  been  moved  bodily  in  a 
posterior  direction  notwithstanding  the  advanced  age  of  the  patient. 

If  regulating  appliances  are  properly  constructed  that  will  permit 
the  production  of  an  independent  static  fulcrum  at  the  occlusal  ends  of 
the  teeth,  so  that  the  entire  power  of  the  machine  may  be  directed  and 
maintained  upon  the  roots  (see  Figs.  874  and  875,  in  section  VI.)  per- 
fect contrusion  of  the  prominence  will  slowly  but  surely  result. 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS.  861 

If  the  teeth  are  crowded,  overlapping,  or  turned  on  their  axes,  a 
correction  of  alignment  may  require  the  extraction  of  a  bicuspid  on 
each  side  in  order  to  regulate  them  without  an  abnormal  protrusion  of 
their  crowns.  This  is  especially  indicated  when  much  retrusion  of  the 
canine  roots  is  desired. 

IV.  Upper  Dental  and  Maxillary  Retrusions. 

Facial  imperfections  which  are  due  to  insufficient  fulness  of  contour 
in  the  central  features  of  the  physiognomy  are  quite  common,  and  vary 
in  degree  from  conditions  that  are  hardly  noticeable  to  those  which  may 
well  be  classed  among  the  most  unhappy  of  facial  deformities. 

There  are  two  distinct  classes  of  this  type  of  facial  irregularity — 
one  being  due  to  a  lack  of  development  of  the  intermaxillary  portion 
of  an  otherwise  harmonious  upper  jaw ;  the  other  to  the  fact  that  the 
entire  upper  jaw  itself  is  too  small  and  too  posteriorly  placed,  in  its 
relations  to  other  parts. 

The  teeth  and  alveolar  process  of  the  retracted  parts  are  prevented 
from  assuming  harmonious  relations,  and  consequently  the  overlying 
features  are  more  or  less  depressed  in  proportion  to  the  contruded  or 
retruded  frame  upon  which  they  depend  for  their  contour. 

The  primary  cause  of  these  conditions  may  be  often  very  obscure 
and  admit  of  nothing  more  tangible  than  conjecture,  and,  not  unlike 
many  of  the  causes  of  irregular  teeth,  be  really  immaterial  to  the  Avork 
of  correction. 

It  may  have  been  caused  by  the  exertion  of  local  physical  forces 
during  the  early  years  of  immaturity  (as,  for  instance,  the  mal-eruptiou 
and  occlusion  of  the  teeth) ;  or  a  local  disturbance  and  interruption  of 
nutrition  from  prenatal  or  postnatal  causes  ;  and  lastly,  but  by  no  means 
rarely,  by  inherent  physical  tendency. 

Retruded  Upper  Incisors  and  Intermaxillary  Process. — In  the  more 
pronounced  deformities  of  this  class  the  physiognomy  will  often  appear 
flattened,  with  prominent  cheek  bones  and  protruding  chin  and  lower 
lip ;  the  upper  incisors  occlude  evenly  with  or  posterior  to  the  lower 
incisors,  and  at  times  are  extensively  inlocked  in  this  position,  as 
instanced  by  the  case  fully  described  and  illustrated  in  Section  I. 

The  upper  incisors,  which  alone  have  their  origin  in  the  intermax- 
illary process,  are  in  their  entirety  posterior  to  a  normal  relative  posi- 
tion. The  labial  inclination  of  the  crowns,  together  with  the  deepened 
incisive  fossae,  will  show  at  once  the  contruded  position  of  the  roots  and 
their  maxillary  surroundings. 

The  upper  lip  resting  upon  the  retruded  teeth  and  the  overlying 
process  is  'proportionately  depressed.  Nor  does  the  facial  defect  end 
here.     The  entire  lower  ])ortion  of  the  nose,  supported  as  it  is  by  the 


H&2      THE  DEVKLOPMESr  OF  ESTHETIC  FACIAL   CONTOURS. 


Fig.  HM. 


nasal  cartilages  which  spriiii,^  tVoin  the  anterior  nasal  spine  and  lateral 
borders  of  the  nasal  oriticc,  is  often  decidedly  affected  in  shape  by  the 
retracting  inflncncc  of  its  snpports. 

When  there  is  a  decided  rctrusion  of  the  entire  upper  lip  and  lower 
p(»rtion  of  the  nose,  with  alse  resting  in  deep  depressions  caused  by  the 

unusual  prominence  of  the  naso-lahial 
folds,  the  ett'ect  is  that  of  an  abnormal 
|)rotrusion  of  surrounding  parts,  pro- 
ducing at  times  a  startling  expression 
of  matiUMty  tiiat  is  only  common  to 
persons  of  advanced  age.  This  oxi)res- 
sion  can  be  seen  in  Fig.  834,  which  is 
that  of  a  girl  only  twelve  years  of  age, 
and  Avill  serve  as  a  type  of  cases  com- 
monly met  with  in  practice. 

Uctrndcd  (iH(l  (\))ifradr(l  I)nd<il  aiul 
Ma.vUlnrtj  Arch.  —  In  this  class  of 
deformities  the  ])hysi()gni»niv.  in  the 
more  pronounced  cases,  has  much  the  same  characteristics  as  those 
described  above,  but  presenting  a  more  general  retraction  of  the  cen- 
tral features,  with  less  pronounced  naso-labial  folds.  Tlie  nose  is 
often  thin  and  the  nostrils  pinched  ;  and  tln>ugh  the  end  of  the  nose 
may  be  depressed,  the  distance  from  the  tip  to  the  more  depressed  lip 
is  often  lengthened.     If  the    patient  is  a  "mouth-breather"  with  the 


Fui.  s;j. 


Via.  s:',(;. 


typical  "open  bite,"  the  deformity  and  the  dithculties  attending  its 
reduction  will  be  greatly  increased. 

Fig.  835  is  from  a  profile  model  of  a  face  of  this  class.  Fig.  836 
is  from  the  same  model  photographed  at  a  slightly  different  angle  to 
show  the  angularity  of  the  features.  • 

Fig.  837  is  a  view  of  the  teeth  in  natural  occlusion.    The  first  lower 


UPPER  DENTAL   AND  MAXILLARY  RETRUSIONS.  863 

bicuspids  have  been  removed  preliminary  to  retruding  the  anterior  teeth 
to  reduce  the  abnormal  protrusion  of  the 

lower  lip  and    esthetically  deepen   the  ^^^'  ^'^'^' 

curve  between  the  border  of  the  lip 
and  the  chin.  The  figure  has  the  ap- 
pearance of  a  perfect  occlusion  of  all 
the  molars,  whereas,  on  account  of  the 
very  great  narrowness  of  the  upper  jaw, 
the  buccal  cusps  of  the  second  molars 
only,  occluded  with  the  lingual  cusps 
of  the  lowers. 

Fig.  838  shows  palatal  views  of  tlie 
upper  arch  before  and  after  treatment. 

Fig.  839  is  a  view  of  teeth  in  natural 
occlusion  after  treatment.  The  entire  upper  dental  arch,  especially  at 
the  apical  zone,  was  considerably  enlarged.  The  "  open  bite  "  was  par- 
tially closed  by  grinding  the  molars  and  partly  by  extruding  the  teeth 
anterior  to  the  molars  with  small  rubber  bands  extending  from  the 
upper  to  the  lower  teeth.  Fig.  840  is  from  a  model  of  the  face  after 
treatment. 

As  mentioned  in  section  II.,  a  depression  of  the  central  features 
such  as  described  is  often  mistaken  for  a  prognathous  jaw,  and  treated 
accordingly. 

Fici.  838. 


A  slight  retraction  of  the  lower  jaw  will  in  nearly  every  case  of  this 
character  produce  an  improvement  in  the  facial  aspect,  because  the  chin 
and  lower  lip  are  brought  into  more  perfect  harmony  with  the  depressed 
central  features.  Such  a  change,  however,  when  it  is  not  demanded, 
can  never  cause  the  beautifying  eifect  produced  by  forcing  the  depressed 
facial  features— in  segments  1  and  2 — forward,  thus  bringing  into  per- 
fect harmony  the  entire  physiognomy. 

This  can  be  verified  with  any  profile  view  of  a  typical  case — as  Fig. 


HH4     THE  i>Kvi:ij>r}fi:x'r  of  kstiiktic  facial  contours. 

841.  Fijj:.  842  i.s  the  satno  face,  oxci^pt  that  the  chin  and  lower  lij)  have 
heen  rotnuled,  producing:  a  certain  improvement,  hnt  not  to  be  coni- 
]iared  with  Fig.  84-'?,  where  the  cliin  and  lower  lip  retain  the  .sunt- 
relative  })osition  to  the  unchangeable  area  as  in  Fig.  841,  while  segments 

Fi.;.  s:<.u.  Fi...  S40. 


1  and  2  have  been  carried  forward,  with  a  result  which  proves  (not 
alone  in  theory,  but  in  practice)  this  to  be  the  only  true  course  to  bring 
about  an  harmonious  and  esthetic  adjustment  of  all  the  features  of  the 

Flu.  S41.  Fi(..  S4-J. 


physiognomy.      Fig.  844   shows  the   actual   difference,  which   may  be 
verified  upon  trial,  between  Figs.  841  and  843. 

Fig.  84o  will  serve  to  illustrate  the  common  result  in  practical  oper- 
ations of  this  character. 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS.  865 

The  contouring  apparatus  (Fig.  873)  that  is  used  to  accomplish  tliese 
Fig.  843.  Fig.  844. 


results  is  fully  described  in  section  VI.  of  this  chapter.     With  it  the 

Fig.  845. 


apical  zone  of  the  anterior  teeth  may  be  enlarged  and  advanced  to  any 


55 


866       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

desired  degri'i*  ;    while  the  niovcinciit  and  inclination  of"  the  crowns  are 
under  the  perfect  control  of  the  opcrat<»r. 

In  this  operation  it  will  he  found  in  a  majority  of  cases,  and  espe- 
eially  with  those  which  arc  hegun  as  early  as  thirteen  or  fourteen  years 
of  age,  that  the  entire  intermaxillary  portion  of  the  upper  jaw  may  he 
carried  hodily  forward  with  the  roots  of  the  ineisors. 

The  depressed  features  of  the  physiognomy — in  segments  1  and  2 
— that  are  dependent  for  their  contour  upon  that  portion  of  the  max- 
illje  are  thus  hrought  into  jx-rfect  harmony  with  other  features  of  the 
face. 

It  is  not  here  implied  that  there  are  not  many  cases  of  real  prog- 
nathous jaw  where  its  retraction,  if  jxtssihle,  would  produce  a  most 
desirable  result  ;  nor  that  such  an  operation  is  impossible  if  recognized 
and  treated  sufficiently  early  with  properly  adjusted  api)aratus  per- 
sistentlv  worn.  The  body  of  the  lower  jaw  can  certainly  be  forced  back 
to  a  more  posterior  position  in  its  relations  to  the  upper,  partly  by  bend- 
ing the  rami  and  necks  of  the  condyles,  and  partly  by  absorption  of  the 
posterior  wall  of  the  glenoid  fossje. 

The  many  failures  that  have  attended  these  operations  have  been 
largely  due  to  the  advanced  age  of  the  patients  and  much  to  the  fact 
that  the  apparatus  is  dependent  upon  tlie  will  or  caprice  of  the  patient 
for  its  persistent  application. 

On  account  of  the  early  maturity  and  ossification  of  the  lower 
maxilla,  these  operations  should  be  undertaken  as  early  as  from  five  to 
ten  years  of  age. 

The  caps  fitted  to  the  head  and  chin  should  be  made  to  exert  a  imi- 
form  pressure  over  the  surfaces  upon  which  they  rest,  admit  of  free 
ventilation,  and  the  whole  apparatus  when  in  place  should  have  no 
j)ro)eeting  parts  which  will  interfere  with  the  comfort  of  the  patient  at 
night. 

Fine  wire  gauze  answers  admirably  for  the  body  of  caps.  It  can  be 
cut  and  readily  shaped  to  any  contour.  First  cut  a  narrow  pattern  of 
thick  pa])er  to  accurately  fit  the  zone  indicated  by  the  desired  border  of 
the  skull-cap.  Duplicate  this  in  thin  tin  ;  solder  the  free  ends  together 
and  fit  to  the  head  to  see  that  it  takes  the  proper  position  and  desired 
flare.  Cut  the  j)ieccs  of  gauze  a  little  in  excess  of  the  required  size 
and  force  it  into  the  rim,  where  it  should  be  tacked  at  one  point  only, 
with  soft  solder.  The  adjustment  is  finally  perfected  by  again  fitting  it 
to  the  head  and  a  line  drawn  along  the  borders  where  it  is  to  be  com- 
pletely soldered.  In  constructing  the  chinpiece,  first  make  a  frame  of 
German-silver  wire,  which  is  then  soldered  to  gauze  as  shown  in  Fig. 
846 — the  whole  to  be  shaped  to  produce  an  eycn  pressure  upon  the 
chin. 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH 


867 


Fig.  846. 


The  projecting  ends  of  the  wire  are  bent  so  as  to  lie  close  to  the  face, 
and  with  sufficient  extension  to  prevent 
the  rubber  bands  pressing  into  the 
cheeks.  The  ends  are  doubled  toward 
each  other  at  the  proper  angle  to  re- 
ceive the  bands. 

Small  wire  triangles  serve  to  attach 
the  rubber  bands  to  the  skull-cap,  bv 
means  of  flat  buttons  sewed  to  the 
gauze.  Finally,  cover  the  rim  of  the 
cap  with  padded  silk  ribbon  and  line 
the  chinpiece  with  some  loosely  woven 
material,  binding  the  edges  with  silk. 

The  skull-cap  is  admirably  adapted 
also  for  applying  a  retruding  force  to  the  upper  anterior  teeth,  by 
means  of  a  bar  which  engages  with  an  encircling  wire  attached  to 
molar  anchorages. 


V.  The  Relations  of  the  Physiognomy  to  the  Saving  and 
Extraction  of  Teeth. 

In  its  widest  scope  this  subject  includes  the  propriety  of  saving,  and 
on  the  other  hand,  the  propriety  of  extracting  certain  teeth  of  the 
deciduous  as  well  as  the  permanent  dental  arches  which  in  any  way 
influence  the  prevention,  the  production,  or  the  correction  of  dento-facial 


F[G.  847. 


Fig.  848. 


irregularities.  Two  phases  of  this  subject  will  be  here  presented.  The 
first  will  be  in  regard  to  the  saving  or  the  extraction  of  the  upper  bicus- 
pids for  patients  older  than  fourteen,  to  correct  a  dental  irregularity ; 
the  second  will  deal  with  the  early  extraction  of  the  bicuspids  to  pre- 
vent an  abnormal  upjier  protrusion. 

In  the  common  form  of  dental  irregularity  shown  by  Fig.  847,  espe- 
cially if  only  the  model  of  the  upper  jaw  were  the  subject  of  study,  it 


HUH       THE' DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

would  in  all  j)r()l)al)ility  he  docidcd  to  extract  the  first  bicuspids  as  the 
best  course  to  jiursue  as  a  Hrst  step  toward  securing  a  perfect  alignment 
of  the  dental  areh  ;  and  the  proceeding  would  probably  be  correct  as  far 
as  the  upper  teeth  alone  were  concerned.  And  again,  if  both  upper  and 
lower  models  were  studied  in  occlusion  and  the  irregularity  of  the  lower 
arch  was — as  is  usually  the  case — in  correspondence  with  that  of  the 
upper,  as  shown  in  Fig.  848,  the  extraction  of  the  lower  first  bicuspids 
would  doubtless,  and  correctly,  be  decided  upon.  This  plan  of  correc- 
tion might  even  be  decided  upon  after  a  superficial  study  of  the  face  of 
the  patient,  which  we  may  supj)osc  to  be  similar  to  that  shown  in  Fig. 
849.     Certainly  the  extraction  of  the  lower  first  bicuspids,  which  have 

Fig.  8o0. 


Fig.  849. 

I 

^^^F          --cZ^itfl^^^^^l 

^^r           j^^^^*^^^^^^ 

^^H^^H 

r                          ^^H^ 

P/^^ 

■    ^^ 

^^^Hj 

1 

ij 

just  begun  to  erupt,  and  the  retraction  of  the  anterior  teeth  would 
reduce  the  apparent  protrusion  of  the  lower  lip  and  bring  it  into  more 
perfect  harmony  with  the  depressed  upjier  lip. 

Yet  when  this  face  is  carefully  studied  from  the  higher  standpoint 
of  esthetic  development  it  becomes  evident  that  the  chin  and  lower  lip 
are  not  protruded,  in  their  relations  to  the  nudar  prominences,  the  bridge 
of  the  nose,  and  the  forehead,  but  that  the  central  features  of  the  physi- 
ognomv  are  depressed  even  to  a  decided  retraction  of  the  lower  portion 
of  the  nose ;  and  that  which  is  really  demanded  in  this  case  is  the  ad- 
vancement or  forward  movement  of  the  entire  intermaxillary  portion  of 
the  jaw  and  incisor  teeth  ;  and  further,  every  tooth  in  that  dental  arch 
is  necessary  for  the  idtimate  retention  of  the  several  parts  in  their 
corrected  position. 

In  the  correction  of  malformations  which  demand  the  protrusion  of 
the  incisors  bodily  with  the  roots  and  intermaxillary  process,  the  posi- 
tion of  the  canines,  as  in  this  case,  will  frequently  prevent  the  proper 
attachment  and  application  of  apparatus  for  producing  the  desired 
effect ;  so  that  it  often  becomes  necessary  to  first  enlarge  the  dental  arch 
and  force  the  crowns  into  partial  alignment  by  ordinary  means,  pre- 


PHYSIOGNOMY  AND   THE  SAVTNO   OF  TEETH. 


bG9 


paratory  to  placing  the  incisors  in  the  grasp  of  contouring  forces.  Fig. 
850  shows  the  position  of  the  teeth  in  this  case  in  the  intermediate 
stage,  the  anterior  teeth  crowded  into  imperfect  alignment,  and  with 
no  special  facial  improvement.  (It  may  be  added  that  at  this  stage 
in  the  operation,  cases  of  this  kind  have  been  considered  finished, 
until  it  was  found  possible  to  enlarge  the  apical  arch.) 


Fig.  851. 


Fig.  852. 


Fig.  851  shows  correctly  the  final  result,  which  was  accomplished 
with  the  contouring  apparatus  described  in  section  VI.  It  will  be 
seen  that  the  incisors  are  in  an  upright  position  and  there  is  now 
ample  room  for  all  the  teeth,  while  the  remarkable  improvement  to  the 
physiognomy  is  poorly  shown  by  the  face  model  Fig.  852. 

Another  case,  that  of  the  upper  arch.  Fig.  853,  if  examined  alone 

Fig.  853. 


and  compared  with  the  upper  of  the  former  case,  or  Fig.  847,  will  be 
found  very  similar.  The  same  crowded  condition  of  the  teeth,  the  same 
lack  of  sufficient  room  for  the  proper  eruption  of  the  canines  ;  and  yet 
this  is  from  the  model  of  a  case  that  absolutely  demanded  the  extraction 
of  the  bicuspids.  At  fourteen  years  of  age  the  irregularity  presented 
the  appearance  shown  in  the  illustration  Fig.  854,  showing  the  models 


STO        '/'///•;   DKVELOPMF.ST  OF  F.STHETIC  FACIAL    COSTOURS. 

of  llir  cnsc  ill  ucclii.-iuii.  The  |);»ti<'nl  was  placed  in  charge  of  a  dentist 
wlio  attein|)led  the  cnn(>cti(»n  of  the  irref^nlarity  without  removal  of  the 
lii-t  hiciispids  :   Fig.  855  shows  the  result  two  years  afterward. 

It  will  be  seen  that  the  incisors  were  forced  forward  to  a  decided 
lai)ial  inclination,  for  the  purpose  of  crowding  the  canines  into  align- 
niciit  ;  and  all  the  anterior  teeth  are  turned  on  their  axes  so  as  to 
occupy  the  least  possible  space.  Fig,  856  is  from  th<'  model  of  the  face 
of  the  patient  at  that  time. 

That  a  mistake  was  made  in  the  ])laii  of  treatment  pursued  is  evi- 
denced by  the  following  considerations  :  First, Tlie  protriision  of  the 
crowns  of  the  upper  anterior  teeth  pr<»dnces  an  unhappy  expression 
of  the  mouth  that  is  equivalent  to  a  deformity,  and  one  thatrcould  not 
be  remedied  in  this  jiarticular  until  certain  members  of  the  dental  arch 
were  removed.  Second,  if  it  were  a  case  in  which  the  maxillary  arch 
was  too  small,  with  a  depressibn  of  the  overlying  features  of  the  face, 

J"i<i.  s.v,.  !  Fig.  .s.")(;. 


the  decided  labial  inclination  of  the  teeth  could  be  overcome  by  an 
enlargement  of  the  apical  zone,  w^hich  would  have  permitted  a  slight 
retrusion  of  the  occlusal  zone  with  a  partial,  if  not  complete,  regulation 
of  the  dental  and  facial  deformity.  But  this  Avas  not  the  condition, 
and  therefore  could  not  be  considered.  The  third  and  most  effective 
argument  is  one  which  should  never  be  overlooked  in  all  cases  where 
the  crowns  flare  outw'ard.  The  conical  shape  of  the  teeth  permits  them 
to  stand  in  perfect  alignment  though  with  a  decided  labial  inclination, 
but  in  this  position  the  interproximal  spaces  so  necessary  to  the  ])reser- 
vation  of  the  teeth  are  so  completely  closed  as  to  cut  off  the  union  of 
interproximal  gum  tissue,  which  must  ultimately  residt  in  the  resorp- 
tion of  the  gum  and  alveolar  process  and  all  the  dire  consequences  that 
follow. 

Had  the  first  bicuspids  been  extracted,  many  difficulties  in  the  regu- 
lation  of  the   teeth   w'ould   have   been   removed  ;  and   what   is   of   far 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH. 


871 


greater  importance,  there  would  have  been  a  satisfactory  result  in  the 
dental  arch  and  physiognomy.  Or  even  further,  had  the  upper  first 
bicuspids  been  extracted  as  soon  as  they  erupted,  together  with  the 
deciduous  canines,  as  will  be  outlined  in  the  second  phase  of  the  subject, 
the  case  would  have  required  little  or  no  other  treatment. 

Fig,  857  shows  the  present  position  of  teeth  after  regulation,  by  re- 
truding  the  anterior  teeth  to  fill  spaces  caused  by  the  extraction  of  the 
bicuspids.     Fig.  858  is  from  a  model  of  the  face  after  treatment.     It 


Fig.  857 


Fig.  858. 


Fig.  859. 


will  be  seen  that  the  interproximal  spaces  between  the  teeth  are  restored, 
while  the  retrusion  of  the  anterior  teeth  allows  the  lips  to  fall  gracefully 
into  proper  position.  The  improvement  in  the  facial  aspect  of  this  and 
all  other  cases  cannot  be  fully  shown 
by  a  plaster  model  of  the  face.  Fig. 
859  was  made  from  a  photograph  of 
this  patient,  taken  a  few  months  after 
the  completion  of  treatment. 

There  are  many  instances  where  the 
early  extraction  of  the  bicuspids,  as  soon 
as  they  can  be  reached  with  the  forceps, 
is  demanded. 

For  example,  adult  faces  with  ab- 
normal protruding  upper  jaws  and 
teeth,  and  with  a  bulged  appearance 
about  the  lower  portion  of  the  nose 
should  have  been  thus  treated.  The  teeth  are  commonly  large,  prom- 
inent, and  crowded,  though  not  always  labially  inclined. 

The   ordinary  upper    protrusions  which  come  under  this  head  are 
so  common  they  will  require  no  further  explanation  or  illustration. 

Upper  protrusions  where  the  teeth  are  not  labially  inclined  are  not 
quite  so  common. 


872       '/'///•;   DEVELOPMENT  OE  ESTHETIC  FACIAL   COSTOVliS. 

Tlu'  alveolar  arcli  is  noci'ssarily  |)r()niinont,  though  the  (lefbrniity  in 
the  main,  as  in  the  nutrc  coninion  forms  of  protrusion,  is  due  to  the 
hirge  si/e  ut"  the  upper  maxilla  proper,  tar  out  of  proportion  to  the 
more  delicately  chiseled  features  which  it  supports  and  forces  into  unsyni- 
metrical  contours.  The  depressions  in  which  the  wings  of  the  nose  rest 
are  more  or  less  obliterated,  as  would  be  occasioned  by  the  sting  of  a 
bee  or  an  alveolar  abscess.  The  nostrils  are  broad  and  open,  and  the 
end  of  the  nose  forced  forward  and  upward  (retrousse)  by  the  protrusion 
of  the  spinous  process  and  cartilaginous  septum.  The  upper  lip  being 
stretched  over  its  inharmonious  frame  is  shortened  so  as  to  cover  the 
teeth  with  difficulty,  and  in  action  readily  rises  to  an  unpleasant  ex- 
posure of  the  teeth  and  gums. 

This  is  an  extreme,  though  not  uncommon,  condition.  Every  stage 
from  this  to  perfect  harmony  characterizes  the  innumerable  varieties  of 
a  certain  type  of  physiognomy. 

Fig.  HOO  is  from  the  face  model  of  a  young  man,  eighteen  years  of 
age,  and  may  be  taken  as  a  type  of  this  character  of  facial  deformity. 

Fi(j.  m\. 


Fig  861  shows  the  teeth  in  occlusion.  The  canines  and  canine  emi- 
nences are  very  jn'ominent,  and  extend  high  up  under  the  wings  of  the 
nose. 

Had  this  case  received  the  early  treatnu'ut  here  advocated,  the 
deformity  would  have  been  prevented  and  the  almost  insurmountable 
difficulties  attending  its  reduction  during  nearly  three  years  of  constant 
treatment  altogether  avoided. 

Any  one  who  has  never  attempted  to  move  the  roots  of  the  canines 
in  a  posterior  direction  for  patients  older  than  sixteen  cannot  begin  to 
aj)preciate  tlie  difficulties  of  such  an  operation. 

And  wliile  the  result  is  quite  satisfactory  under  the  circumstances, 
as  will  be  !^een  by  Figs.    862  and  863,   the  physiognomy  is  not  nearly 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH. 


873 


so  perfect  esthetically  as  it  would  have  been  had  the  case  received  proper 
early  treatment. 

The  important  consideration  from  a  surgical  and  artistic  standpoint 
in  nearly  all  cases  of  abnormal  upper  protrusion  is  :  Has  not  Nature 
been  forced  to  produce  these  conditions,  wholly  or  in  part,  to  accommo^ 
date  teeth  that  were  too  large  for  the  natural  or  inherent  frame  and 
overlying  features  ?  And  could  we  have  helped  Nature  in  the  early 
years  of  development,  by  making  it  unnecessary  for  her  to  produce  this 
excessive  growth  of  bone  for  the  development  and  sustenance  of  all 
these  large  teeth  ? 

The  same  is  true  where  the  protrusion  seems  to  have  been  caused 
by  the  inheritance  of  an  inharmoniously  large  jaw  crowded  full  of 
teeth. 

We  certainly  cannot  reduce  the  size  of  the  teeth,  but  we  can  reduce 
their  number,  and  in  so  doing  reduce  the  size  of  the  destined  maxillary 


Fig.  862. 


Fig.  S63. 


and  dental  arch.  But  we  must  make  no  mistake.  The  danger  of  ad- 
vocating such  ji  principle  to  those  who  have  given  this  branch  of  den- 
tistry little  thought  is  that  teeth  will  be  extracted  to  accommodate  an 
overcrowded  condition  in  the  arch,  with  little  or  no  thought  of  the 
physiognomy,  when  a  careful  and  properly  pursued  study  of  the  features 
and  their  comparison  with  the  parental  types  will  show  that  in  reality 
the  dental  and  maxillary  arch  should  be  enlarged,  and  every  tooth  re- 
main to  induce  its  natural  growth  and  development.  If  this  has  not 
been  attained  by  natural  processes,  every  tooth  should  certainly  remain 
to  hold  the  artificially  developed  arch  in  place. 

How  are  we  to  study  the  undeveloped  face  of  a  child,  every  linea- 
ment of  which  is  passing  through  rapid  changes  of  growth,  with  a  view 
of  determining  whether  or  not  the  dental  arch  and  jaws  will  be  too 
prominent,  or  that  other  features  will  not  enlarge  to  a  harmonizing 
proportion  ? 


S74       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   ro.WTOURS. 

A  most  wundcrt'iil  provision  of  Naturt'  in  dentition  canscs  tiie  full- 
sized  crowns  oi'  teeth  to  erupt,  as  regards  time,  somewhat  in  proportion 
to  the  natural  growth  and  enlargement  of  the  jaws.  And  even  when 
they  do  not  erupt  earlier  than  is  normal,  or  when  their  natural  eruption 
is  not  interfered  with  by  the  premature  extraction  of  the  deciduous 
teeth,  they  are  usually  obliged  to  take  an  irregular  position  or  attitude 
at  first,  and  await  the  growth  of  the  jaw  which  permits  them  to  become 
regular. 

It  is  perhaps  a  safe  general  rule  to  never  extract  a  permanent  tooth 
for  the  purpose  alone  of  correcting  a  dental  irregularity,  unless  the  jaw 
has  ceased  growing  ;  and  never  then  unless  it  is  shown  by  a  careful  study 
of  the  position  of  the  teeth — their  relation  and  occlusion — that  the  den- 
tal arch  should  not  be  expanded  ;  or  by  a  study  of  the  j^hysiognomy, 
that  the  alveolo-dental  arch  should  not  be  enlarged. 

In  a  study  of  the  relations  of  the  teeth,  the  jaws,  and  the  physiog- 
nomy of  a  child  with  the  view  of  determining  the  advisability  of  extrac- 
tion to  correct  or  ])revent  the  ultimate  production  of  a  facial  deformity 
or  marked  imperfection  of  the  features,  it  may  become  necessary  to 
study  the  ]>hysiognomies  of  both  ])arents  and  ]K)ssibly  other  members 
of  the  family,  to  correctly  determine  the  influence  of  inheritance. 

In  this  comparison  of  temperament,  physical  frame,  features,  and 
teeth,  it  may  require  no  more  than  a  glance  to  furnish  all  the  data  that 
will  be  of  practical  use. 

Usually  but  one  parent  accompanies  the  little  patient,  and  a  study 
of  that  one  physiognomy  may  be  a  sufficient  guide ;  if  not,  other  mem- 
bers of  the  family  should  be  seen. 

If  there  be  a  marked  difference  in  the  parents  it  may  not  be  difficult 
to  determine  from  which  the  child  has  inherited  the  teeth,  by  the 
j)eculiar  shape  and  size  of  the  incisors  alone.  But  in  regard  to  the 
maxillie  in  an  undeveloped  condition  there  w^ill  be  more  difficulty, 
though  it  is  w'cll  to  remember  that  the  deciduous  teeth  are  rarely  irregu- 
lar or  disproportionate  in  size  to  the  frame  and  facial  features.  If,  there- 
fore, there  be  a  more  than  natural  difference  in  the  size  of  the  permanent 
and  deciduous  teeth  it  will  indicate  union  of  inharmonious  types. 

In  this  connection  it  must  not  be  forgotten  that  the  crowns  of  the  per- 
manent incisors  are  almost  invariably  far  too  large  for  their  undevel- 
oped surroundings.  The  apparently  disproportionate  size  of  the  cen- 
tral incisors  to  that  of  the  jaw  is  a  subject  of  frequent  and  anxious 
parental  comment.  If  the  occlusion  of  the  incisor  teeth  be  far  from  a 
normal  type  in  their  anterior  relations,  and  the  same  condition  exists 
with  either  parent,  it  is  an  indication  of  what  the  child  will  become  if 
unaided  by  dental  skill,  especially  if  a  similarity  be  noted  in  other 
particulars. 


PHYSIOGNOMY  AND   THE  SAVING   OF  TEETH.  875 

With  differences  in  temperament,  compare  general  shape  and  size  of 
the  eyes,  brows,  ears,  and  teeth. 

Other  features  are  so  subject  to  change  in  the  processes  of  natural 
growth  and  development  that  they  cannot  be  relied  upon  to  furnish 
legitimate  data.  For  instance,  the  nose  may  change  in  a  few  years 
of  late  youthful  development  from  one  originally  small  and  short — 
and  over  the  nasal  bones  decidedly  depressed — to  a  form  different  in 
every  particular. 

When  neither  parent  presents  the  same  unsymmetrical  relations  that 
promise  to  prevail  in  the  child,  the  cause  may  be  a  union  of  the  large 
teeth  of  one  parent  with  the  small  jaws  of  the  other. 

When  the  teeth  of  the  parents  are  decidedly  dissimilar  in  size,  it 
may  be  possible,  as  before  stated,  to  determine  with  certainty  from 
which  parent  the  teeth  of  the  child  are  inherited,  and  when  the  teeth 
and  jaws  of  the  other  parent  are  small  and  other  features  are  similar 
to  those  of  the  child,  it  indicates  a  union  of  undiluted  types. 

All  these  things  are  of  the  utmost  importance  in  determining  the 
impropriety  of  extracting  certain  teeth  to  reduce  an  apparent  abnormal 
protrusion,  which  may  in  time  become  symmetrical  in  its  relation  by 
the  natural  growth  of  the  jaws  and  other  features  ;  and  also  the  equally 
culpable  error  of  saving  teeth,  or  the  failure  to  extract  teeth,  whose 
very  presence  in  the  arch  obliges  Nature  to  reproduce  a  parental 
deformity,  or  produce  an  acquired  deformity,  by  an  effort  to  sustain  the 
large  teeth  of  one  parent  in  conjunction  with  the  small  jaws  of  the 
other. 

For  a  child  with  an  abnormal  upper  protrusion  similar  to  Figs.  864 
and  865,  with  teeth  prominent  and  crowded  in  an  arch  which  does  not 

Fig.  864.  Fig.  865. 


admit-of  correcting  by  a  lateral  expansion,  extract  the  first  bicuspids  as 
early  as  possible,  even  before  their  eruption  is  completed,  together  with 
the  deciduous  canines — unless  it  be  one  of  those  very  rare  instances 
where  the  first  permanent  molars  cannot  be  saved. 


.s7(i     TiiK  i>i:vi:i.(>rMi:sT  of  estiiettc  facial  contours. 

The  sanu'  is  true  of  the  lower,  ulicii  there  is  reason  to  believe 
there  will  l)e  a  (lis|)roj)ortioiiate  over-develojunent  of  the  lower  dental 
a  roll. 

In  the  t)nlinary  course  of  eruption  tiie  dovolopmcMit  and  eruption  of 
the  permanent  canines  are  doubtless  more  influential  than  those  of  other 
teeth  in  emphasizint!;  an  anterior  j)rotrusion  of  the  eeutral  features  of 
the  ])hysiogn()my. 

In  tiio  eourse  of  their  eruj)ti()n  they  are  oblifjed  to  crowd  into  align- 
ment   aloui:'   the    mesial   surfaces  of  the    roots   and    crowns   of  the  first 


Fig.  80(5. 


Fi(i.  sc:. 


Fig.  8()S. 


bicuspids — which  at  this  time  represent  the  immovable  bases  of  the 
arch — with  the  result  that  the  incisive  and  intermaxillary  portion  of 
the  arch  is  forced  forward  to  a  more  pronounced  position.  This  move- 
ment lias  been  shown  to  be  not  im])ossible  or  difficult  of  attainment  by 
artificial  force,  even  much  later  in  life. 

With  the  first  bicuspids  and  deciduous  canines  removed  sufficiently 
early  there  are  numberless  instances  when  the  arch,  anterior  to  the 

second  bicuspids,  would  be  diminished  the 
Avidth  of  a  bicuspid,  without  resort  to  arti- 
ficial  means. 

By  the  exertion  of  a  slight  traction  force 
from  an  occipital  base  of  anchorage  the 
sockets  of  the  temporary  canines  will  be 
closed  by  the  permanent  laterals,  and  the 
])ermauent  canines  in  the  course  of  their 
eruption  will  be  deflected  into  tlie  alveoli 
of  the  extracted  bicuspids. 

Figs.  866  and  (S67  represent  one  case  out 
of  many  under  treatment  by  this  method, 
though  not  all  by  the  occipital   method. 
Fig.  868  shows  the  position  of  the  teeth  after  about  two  months 


THE  CONTOURING  APPARATUtS.  877 

of  traction  force  from  molar  anchorages ;  the  protrusion  not  being  so 
pronounced  as  to  demand  the  use  of  the  skull-cap. 

It  will  be  seen  by  the  canine  eminences — though  far  better  shown 
upon  the  model  itself — that  the  position  of  the  canine  crowns  is  imme- 
diately over  the  former  alveoli  of  the  first  bicuspids.  As  they  continue 
to  grow  downward  in  this  somewhat  open  channel,  their  roots,  which 
are  not  at  present  developed,  will  grow  upward,  the  teeth  in  their  en- 
tirety finally  taking  a  position  and  inclination  similar  to  that  of  the 
bicuspids  which  they  replace,  and  considerably  posterior  to  that  which 
they  were  otherwise  destined  to  occupy. 

The  patient,  nine  years  of  age,  had  the  teeth,  eyes,  ears,  and  general 
temperament  of  the  father,  whose  upper  arch  was  abnormally  protruded 
in  a  similar  manner,  which  was  the  nmon  d'Hre  for  dental  aid. 

Had  the  father's  teeth  been  in  proper  relative  and  symmetrical 
position,  and  similaV  to  the  son's  in  other  particulars  which  could  be 
legitimately  used  as  data,  it  would  have  been  an  argument  in  favor 
of  non-extraction  with  the  expectation  of  other  treatment  later ;  but 
it  should  not  have  been  passed  upon  without  seeing  the  mother.  Had 
the  mother's  teeth  been  found  small  and  the  general  physical  features 
cast  in  a  more  delicate  mould  than  her  husband's,  investigations  along 
other  lines  would  have  been  required  with  the  view  of  determining 
if  the  child  had  not  the  large  teeth  of  the  father  and  small  jaws  of  the 
mother ;  in  which  case  extraction  would  also  have  been  indicated. 

VI.  The  Contouring  Apparatus. 

The  limited  area  upon  which  force  can  be  applied  to  a  tooth,  com- 
pared with  that  portion  covered  by  the  gum  and  imbedded  in  a  bony 
socket,  has  made  it  next  to  impossible,  with  all  ordinary  methods,  to 
move  the  apex  of  the  root  in  the  direction  of  the  applied  force  ;  nor 
could  this  ever  be  accomplished  with  force  exerted  in  the  usual  way  at 
one  point  upon  the  crown,  however  near  the  margin  of  the  gum  it  may 
be  applied,  for  the  opposing  margin  of  the  alveolar  socket  must  receive 
the  greater  portion  of  this  direct  force,  and  in  proportion  to  its  resist- 
ance it  will  become  a  fulcrum  exerting  a  tendency  to  move  the  apex  of 
the  root  in  the  opposite  direction. 

But  if  in  the  construction  of  the  apparatus  a  static  fulcrum  is  created 
independent  of  the  alveolar  process  at  a  point  near  the  occluding  portion 
of  the  crown,  while  the  power  is  applied  at  a  point  as  far  upon  the  root 
as  the  mechanical  and  other  opportunities  of  the  case  will  permit,  the 
apparatus  becomes  a  lever  of  the  third  kind,  the  power  being  directed 
to  a  movement  of  the  entire  root  in  the  direction  of  the  applied  force. 

This  proposition  is  made  plain  by  reference  to  diagrams.  In  Fig. 
869  let  A  be  a  point  upon  a  central  incisor  at  which  force  is  applied  in 


87<S        THE   DKVELOPMKST  OF  ESTHETIC  FACIAL   COyTOURS. 


the  direction  indicated  bv  the  arrow,  tlun  will  tlic  opposing  wall,  h,  of 
the  alveolar  socket  near  its  margin  receive  nearly  all  of"  the  direct  force ; 
and  in  proportion  to  its  resistance  will  tlif^-e  l)c  a  tendency  to  move  the 
root  in  the  opposite  direction.  This  will  also  hold  good  even  if  the 
force  be  applied  at  A,  Fig.  870,  or  as  far  upon  the  root  as  may  be  per- 
■niitted  bv  attaching  a  rigid  ni>right  bar,  c,  to  the  anterior  surface  of  the 


Vui  suit. 


Fig.  870. 


crown  ;  the  only  difference  being  that  the  direct  force  is  distributed 
over  a  greater  area.  But  if,  as  in  Fig.  871,  to  the  lower  end  of  (  a 
traction  wire  or  bar,  f,  is  attached  and  if  the  mechanical  principles  of 
the  machine  be  further  enforced  by  uniting  its  posterior  attachment  to 
the  anchorage  of  the  power  bar,  P,  the  anchorage  force  will  be  materially 
neutralize<l  and  an  independent  static  fulcrum  at  D  created.  The  appa- 
ratus now  will  distribute  its  force  over  the  entire  root,  and  give  com- 
plete direction  and   control   of   whatever   power  is  put  into   it.     The 


Fi«.  871. 


entire  tooth  may  bo  carried  forward  bodily  or  either  end  may  be  made 
to  move  the  more  rapidly.  The  force  thus  dire(;ted  to  the  ends  of  the 
roots  will  have  an  increased  tendency  to  move  the  more  or  less  yielding 
bone  in  which  they  are  imbedded. 

For  practical  illustrations  of  what  has  been  accomplished  by  an 
apparatus  of  this  kind  see  cases  described  in  sections  I.,  IV.,  and  V.  of 
this  chapter. 

Tlio  contouring  apparatus  is  made  entirely  of  German  silver,  with 
the  exception  of  the  nuts,  which  are  of  nickel.  German  silver  is  pre- 
ferred, not  because  it  is  cheaper  than  gold  and  platinum,  but  because  it 


THE  CONTOURING  APPARATUS.  879 

possesses  certain  qualities  which  render  it  adapted  for  the  purpose  to 
which  it  is  applied. 

In  making  the  banding  material  for  this  apparatus,  thoroughly  an- 
neal a  piece  of  wire  No.  13  and  pass  it  through  the  rollers — with  an 
occasional  re-annealing — until  it  is  reduced  in  thickness  to  Nos.  35  and 
38  (or  0.004  and  0.0056  of  an  inch).^  This  will  give  bands  about  \  and 
Y^  of  an  inch  wide.  Use  the  thinner  material  for  the  anterior  teeth 
and  the  thicker  for  the  anchorage  appliance.  Before  using,  it  should  be 
wound  into  rolls  and  brought  to  an  even  red  heat,  held  there  for  ten 
minutes,  then  allowed  to  cool  slowly.  This  will  ensure  perfect  softness 
and  adaptability. 

In  taking  the  measurements  for  the  bands,  cut  from  the  material 
the  proper  length,  and,  holding  the  ends  of  the  loop  between  thumb  and 
finger,  pass  it  over  the  tooth  to  be  fitted.  When  in  place  bend  the  ends 
sharply  at  right  angles  and  finally,  grasping  the  two  ends  in  the  pliers, 
draw  the  band  firmly  around  the  tooth.  The  bands  for  the  anterior 
teeth  should  extend  at  this  time  sufficiently  beneath  the  approximal  bor- 
ders of  the  gum  to  assure  complete  extension  to  the  labio-  and  linguo- 
gingival  borders.  The  approximal  extension  should  be  cut  down  to  the 
gingival  border  of  the  enamel  in  the  final  finishing  of  the  apparatus. 

After  the  bands  are  soldered  carefully,  fit  and  burnish  them  to  the 
teeth.  In  order  to  obtain  perfect  adaptation  it  often  becomes  necessary 
to  contour  them  slightly  with  the  proper  pliers.  The  joint  which  pro- 
jects on  the  anterior  surface  of  the  bands  for  the  anterior  teeth  should 
be  placed  at  one  side  of  the  middle  to  allow  the  upright  bar  c.  Fig.  871, 
to  rest  exactly  along  the  median  line. 

When  the  teeth  are  so  crowded  together  that  the  banding  material 
cannot  be  passed  freely  between  them  they  should  first  be  separated 
with  waxed  tape.  It  is  to  be  preferred  to  rubber  because  sufficient 
space  is  obtained  in  twenty-four  hours  with  little  or  no  discomfort  to 
the  patient  beyond  the  general  soreness  of  the  teeth,  which  must  always 
follow  the  preliminary  steps  of  a  regulating  operation.  These  tapes 
are  allowed  to  remain  between  the  teeth — renewing  them  each  day — till 
the  final  attachment  of  the  apparatus. 

The  first  appliance  to  be  described  is  that  designed  for  moving  the 
roots  of  the  upper  incisors  forward. 

Before  it  is  possible  to  apply  the  contouring  force  it  is  frequently 
necessary  to  first  move  the  crowns  of  very  irregular  teeth  into  align- 
ment somewhat — and  even  to  rotate  them — so  as  to  bring  them  into  a 
position  to  be  properly  grasped  by  the  power  bar  of  the  apparatus. 
(See  Fig.  850,  with  description.) 

1  In  this  description  it  will  be  understood  that  German  silver  is  the  metal  indicated 
and  Brown  &  Sharp' s  gauge  that  by  which  thicknesses  are  measured. 


880       THE  DKVKLnPMEST   OF  ESTHETIC  FACIAL    coSTOl'RS. 

When  the  bands  have  been  Htted  as  described  above,  tliey  should  be 
placed  upon  the  four  ineisors  and  a  phister  impression  taken  of  the 
labial  surfaces  of  the  bands,  teeth,  and  adjoininj;  gum.  For  a  tray  to 
<rarry  the  plaster  to  place  use  a  thin  piece  of  lead  cut  the  proper 
size. 

After  the  impression  is  removed,  carefully  remove  the  bands  and 
place  them  in  their  respective  positions  on  the  impression;  the  joint»s 
of  the  bands  will  serve  to  guide  them  to  place.  This  when  tilled  with 
Teague's  or  other  investing  material  will  give  a  model  with  the  bands 
in  position,   to  which  may  be   fitted  and  soldered   the  upright  bars. 

The  upright  bars  are  made  of  Xo.  l.'>  wire,  bent  and  filed  to  fit  the  an- 
terior face  of  the  band  and  tooth  along  the  median  line  of  its  axis,  and  also 
the  gum  to  about  i  of  an  inch  above  its  margin.  In  soldering  them  to 
the  bands,  completely  fill  the  V-shaped  spaces  on  either  side  the  upright 
bars,  to  give  sufficient  rigidity  and  finish  to  the  appliance.  After  they 
have  been  soldered  and  removed  from  the  model  they  are  further  finished 
by  filing  the  bars  flat  on  the  sides  which  lie  next  to  the  gum,  tapering 
them  to  one-half  their  diameters  at  the  upper  ends.  It  is  against  this 
surface  that  the  power  bar,  r,  is  to  rest,  as  shown  in  Fig.  871.  The 
upright  bar  may  also  be  flattened  somewhat  over  the  face  of  the  tooth, 
but  not  at  the  point  where  it  leaves  the  band  for  the  gum,  as  full 
strength  and  rigidity  are  required  here.  (In  Fig.  871  the  engraver  has 
made  the  upright  bar  a])pear  far  too  light  at  this  point — marked  c — for 
practical  use  in  sustaining  the  great  force  of  the  power  bar  at  b.) 

The  bars  having  been  cut  off  even  with  the  occluding  ends  of  the 
teeth,  and  properly  rounded  and  polished,  the  small  transverse  grooves, 
22  gauge,  which  is  much  smaller  than  shown  in  Fig.  871.  Instead  of 
filing  a  groove  in  the  upright  to  engage  with  the  fulcrum  bow,  I  now 
cut  it  off  and  solder  to  its  occlusal  end  a  thin  open  tube  attachment, 
which  seats  the  wire  more  firmly  close  to  the  face  of  the  tooth,  and  at  a 
])()int  somewhat  above  its  incisal  edge. 

In  constructing  the  anchorage  j)ortion  of  the  apparatus  to  be  attached 
to  the  posterior  teeth  too  much  care  cannot  be  observed  in  order  that 
the  several  parts  perform  the  work  assigned  to  them  and  the  greater 
portion  of  force  be  neutralized  at  points  of  anchorage. 

When  the  second  molars  have  fully  erupted,  band  the  first  and 
second  molars — otherwise  the  second  bicuspids  and  first  molars — and 
sometimes  all  three  teeth.  Where  it  becomes  advisable  to  apply  this 
particular  form  of  force  before  the  eruption  of  the  second  bicuspids, 
the  second  deciduous  and  first  permanent  molars  will  answer  for  the 
purpose. 

The  banding  material  sh(tuld  be  as  wide  as  the  tooth  will  permit. 


THE  CONTOURING  APPARATUS.  881 

and  in  thickness  No.  35  (or  .0055  of  an  inch).  When  the  bands 
have  been  made  as  described  and  perfectly  fitted,  place  them  in 
the  positions  they  are  to  occupy  and  take  a  plaster  impression — 
one  side  at  a  time — allowing  the  plaster  to  barely  cover  the  bands, 
but  sufficiently  extensive  to  show  on  the  model  the  bicuspids  and 
canines,  for  reasons  that  will  become  obvious. 

After  removal,  replace  the  bands  accurately  in  their  positions  in  the 
impression,  and  fill  as  before  with  Teague's  or  any  good  investing 
material. 

This  material  will  give  a  model  that  will  hold  the  bands  in  exact 
relative  position  while  they  are  being  soldered,  and  one  also  that  is  suf- 
ficiently extensive  to  enable  the  placing  and  soldering  of  the  tubes  in 
proper  position  and  direction — a  thing  of  the  utmost  importance. 

In  selecting  the  tubes  the  smaller  should  loosely  fit  the  threaded  end 
of  No.  22  wire,  which  is  the  size  to  use  for  the  fulcrum  bow,  F.  The 
size  of  the  larger  tube  should  be  governed  by  the  size  of  the  power  bow — 
i.  e.,  when  the  jaw  is  large  with  fully  developed  teeth,  or  when  the  dis- 
tance is  considerable  from  anchorage  appliances  to  the  upright  bars  on 
the  anterior  teeth,  the  size  of  the  power  bow,  p,  should  be  No.  13.  It 
should  rarely  be  smaller  than  No.  15,  though  when  the  operation  is 
attempted  for  very  young  children  No.  16  will  answer  the  purpose. 
But  the  ordinary  German-silver  wire  of  the  shops  of  these  sizes  will 
not  do.  It  must  be  specially  prepared  in  order  to  withstand,  without 
bending,  the  great  force  exerted  upon  a  bent  bow.  All  wire  for  power 
bows  should  be  drawn,  without  annealing,  from  No.  8,  and  be  nearly 
as  rigid  as  tempered  steel.  In  the  selection  of  tubes  the  larger  should 
loosely  fit  the  threaded  end  of  the  power  bow,  and  be  |^  to  |  of  an  inch 
long. 

An  important  feature  is  the  position  of  the  power  bow  tubes.     They 

should  be    so   placed    and    soldered   to  the  ^ 

111  1  I.  Fici-  872. 

anchorage  bands  that  the  power  bow — when 

placed  in  the  tubes — will  extend  from  it  in  a 

straight  line  to  the  canines,  where  it  bends 

over  to  engage  with  the  upright  bars,  C.    (See 

Fig.  871 .)     If  this  precaution  be  not  taken, 

but  instead  the  power  tubes  are  soldered  in 

the  ordinary  way,  in  contact  with  the  buccal 

surfaces    of  the   bands,  the   power  bow,  in 

most  instances,  will  require  to  commence  its 

encircling  bend  immediately  upon  emerging 

from  the  tubes,  with  a  decided  weakening  of 

its  rigidity  and  possible  failure. 

In  order  to  obtain  the  proper  position  it  will  often  be  advisable  to 

56 


882       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

rest  the  posteriDr  end  of  the  larger  tube  upon  that  of  the  smaller,  as 
shown  in  Figs.  872  and  873,  All  projecting  portions  that  are  liable  to 
irritate  the  mouth  should  be  rounded  and  polished. 

In  soldering  tubes  to  place  use  a  sligiitly  lower  grade  of  silver  solder 
than  that  used  to  join  the  bands.  Use  sufticient  to  thoroughly  unite  all 
the  joints,  and  fill  all  V-shaped  spaces,  being  careful  to  turn  the  joints 
of  the  tubes  toward  the  bands  that  they  may  be  closed.  Thoroughly 
unite  the  approximal  surfaces  of  tlu'  bands  and  reinforce  the  lingual  V 
with  an  extra  piece.     (See  Fig.  872.) 

In  finishing  the  apparatus  the  soldered  parts  should  be  boiletl  in  a  solu- 
tion of  sulphuric  acid  to  remove  the  borax  and  oxids.  After  being  neu- 
tralized and  brushed  they  are  ready  for  the  trial  fitting  to  the  mouth. 

In  this  operation  the  bands  should  be  perfectly  fitted  to  the  position 


Protriisii>n  apparatus. 

tliey  are  to  occupy — the  upright  bars  readjusted,  if  necessary,  and  nil 
surplus  material  cut  away — sharp  and  rough  surfaces  smoothed  and 
polished,  and  the  gingival  and  occluding  edges  of  the  bands  carefully 
burnished  to  the  teeth. 

In  constructing  the  power  bow  the  anchorage  attachments  should  be 
placed  upon  a  plaster  model  of  the  teeth,  in  order  to  accurately  deter- 
mine its  length  and  the  lengths  of  its  threaded  ends,  then  properly 
shaped  to  the  gum  over  which  it  is  to  rest.  The  rigidity  of  a  No.  13 
power  bow  nmkes  it  necessary  that  it  be  absolutely  accurate  in  shape. 
When  finally  adjusted  its  arch  should  perfectly  conform  to  the  gum 
tissue  over  which  it  passes,  while  its  threaded  ends  should  lie  in  their 
respective  anchorage  tubes  without  exerting  the  slightest  tension  in  any 


THE  CONTOURING  APPARATUS.  883 

direction,  otherwise  the  anchorages  will  be  carried  in  the  direction  of  its 
force  to  restore  equilibrium.  The  final  shaping  of  the  power  bow  should 
therefore  always  be  done  at  the  chair  in  the  preliminary  assembling  of 
the  apparatus. 

One  end  of  the  bow  should  be  placed  in  its  anchorage  tube  with  the 
other  end  exactly  parallel  with  the  other  anchorage  tube.  This  is  to  be 
repeated  with  the  opposite  ends,  before  placing  them  both  in  position. 
In  front  the  bow  should  rest  about  ^  of  an  inch  above  the  gingival  borders 
of  the  centrals.  When  in  position,  prevented  by  the  nuts  from  more 
than  lightly  resting  against  the  gums,  no  expanding  or  contracting  force 
should  be  exerted  upon  its  anchorages. 

The  bending  of  this  large  and  rigid  wire  to  the  angles  necessary  can- 
not be  easily  accomplished  without  the  pair  of  pliers  especially  con- 
structed for  the  purpose. 

With  the  anchorages  and  power  bow  temporarily  in  position,  the 
incisor  bands  should  now  be  placed  with  their  upright  bars  resting 
upon  the  bow,  by  which  their  lengths — which  should  not  be  above 
the  bow — may  be  determined  and  their  exact  positions  marked  upon 
the  bow. 

When  the  bow  is  removed  these  places  should  be  grooved  with  a 
square-edge  file  to  about  ^  the  diameter  of  the  bow,  so  that  the  incisor 
bars  when  finally  in  place  will  drop  into  these  grooves. 

This  method  has  a  great  advantage  over  the  former  one  of  flattening 
the  power  bow.  It  holds  the  uprights  firmly  in  its  grasp  with  no  possi- 
bility of  slipping  along  its  surface,  and  it  presents  a  more  even  surface 
to  the  lip. 

When  the  apparatus  is  finished  and  heavily  gold-plated  it  is  ready 
for  the  final  temporary  assembling,  which  should  always  be  done  with 
this  apparatus  before  the  final  cementing  in  position.  The  teeth  are 
brushed  with  pumice  stone,  a  napkin  placed  in  the  mouth,  and  the  teeth 
and  surrounding  gum  dried  with  spunk,  which  is  also  to  be  packed 
around  the  teeth,  where  it  is  held  firmly  in  position  while  the  cement 
is  being  prepared  and  placed  in  the  bands  by  an  assistant.  All  material 
used  in  polishing  is  to  be  removed  from  the  inner  surface  of  the  bands, 
and  the  surfaces  scraped  or  scratched  with  a  sharp  excavator. 

The  cement  should  be  mixed  thoroughly,  but  rapidly,  to  the  con- 
sistence of  thick  cream,  and  scraped  from  the  spatula  along  the  upper 
and  inner  edges  of  the  bands. 

When  each  part  of  the  appliance  is  ready,  it  is  forced  quickly  and 
firmly  to  its  position  ;  its  final  adjustment  being  perfected  by  the  use 
of  the  mallet  on  a  wood  plugger  resting  upon  the  soldered  parts. 

One  of  the  anchorages  is  first  placed,  and  when  the  cement  is  thor- 
oughly hard  the  power  bow  is  adjusted  in  its  tube  and  in  position,  and 


884       THE  DF.VKlJnWKyT  OF  FSTIIETKJ  FACIAL   CONTOFRS. 

then  the  otluT  imchorai^o  is  jjlufcd  l)v  jKissing  it  ba(;k  so  that  its  power 
tube  will  slide  over  the  extended  end  of  the  bow  and  forward  to  position. 

On  aeeount  of  the  intense  riji^idity  of  the  power  bar  it  is  important 
that  when  it  is  in  place  on  the  teeth  the  threaded  ends  slutuld  lie  within 
their  respective  anchorage  tubes  without  exertinir  the  slightest  force  in 
any  direction  until  it  is  applied,  as  inten<h'd,by  the  power  of  the  screws  ; 
therefore  great  care  should  be  observed  in  giving  to  it  the  j)ro|)er  shape, 
by  bending  as  accurately  as  possible  upon  the  plaster  model,  and  after- 
ward by  a  trial  fitting  in  the  mouth  before  cementing  the  anchorage 
bands. 

With  the  anchorage  attachments  and  power  bar  in  position  the  bands 
are  to  be  cemented  to  the  anterior  teeth.  As  each  band  is  carried  to  its 
place,  it  should  be  seen  that  the  flattened  surface  of  the  upright  bar  is 
pressed  down  firmly  into  its  groove  on  the  bar,  so  that  an  even  force 
will  be  given  to  each  of  the  teeth  when  power  is  applied — it  being  pre- 
supposed that  in  the  trial  fitting  of  the  parts  the  power  bar  was  shaped 
so  as  to  engage  perfectly  with  the  upright  bars — the  free  ends  of  the 
latter  extending  slightly  above  it. 

The  fulcrum  bow,  No.  22,  is  adjusted  in  the  same  mann(>r  as  any 
alignment  bow.  Close  the  incisor  open  tube  attachments  and  burnish 
all  rough  and  projecting  edges. 

Fu..  874. 


The  sjime  kind  of  apparatus  may  be  employed  upon  the  lower  in- 
cisors with  perfect  success,  though  there  will  not  be  the  same  tendency 
to  carry  the  entire  alveolar  ridge  for^vard  with  the  roots  as  on  the 
upper,  the  change  being  largely  by  a  metamorphosis  of  alveolar  tissue. 

An  apparatus  for  retruding  the  roots  of  the  antorior  teeth  is  con- 
structed in  a  very  similar  manner.  The  direction  of  the  two  forces 
being  reversed,  it  becomes  necessary,  however,  to  make  certain  import- 
ant variations.  The  power  bar  (p.  Fig.  896)  now  exerting  a  traction 
force,  No.  16  will  be  found  sufficiently  large  for  all  pur])oses.  It  is 
not  flattened,  but  rests  in  grooves  cut  in  the  anterior  surfaces  of  the 
upright  bars,  B.     The  power-bar  tubes  should  be  soldered  closely  to  the 


THE  CONTOURING  APPARATUS.  885 

anchorage  bands  so  that  the  nuts  which  now  work  at  the  posterior  ends 
of  the  bar  will  not  irritate  the  mucous  membrane  of  the  cheek.  The 
fulcrum  bar,  f,  exerting  in  this  apparatus  a  jack-screw  force,  should  be 
No.  16.  It  is  flattened  along  its  middle  portion  to  engage  with  the 
occluding  ends  of  the  upright  bars  at  D,  provision  being  made  for  the 
purpose  in  the  construction. 

The  power  of  the  two  forces  being  so  great  upon  the  upright  bars, 
with  a  tendency  to  lift  the  occluding  ends  from  their  attachments,  and 
thus  allow  the  free  ends  to  press  into  the  gum,  it  is  important  with  this 
apparatus  that  the  occluding  end  attachments  be  reinforced  by  soldering 

Fig.  875. 


to  the  bands  an  extra  piece  of  banding  material  that  shall  extend  from 
the  labial  face  over  the  occluding  end  of  the  tooth  to  the  lingual  portion 
(shown  in  Fig.  875). 

After  the  joint  of  the  band  has  been  soldered,  the  reinforcing  piece, 
of  sufficient  length  for  the  purpose,  should  first  be  soldered  to  the  labial 
face  alongside  of  the  joint ;  then  the  band  is  perfectly  fitted  to  the 
natural  tooth — the  extra  piece  being  bent  over  and  burnished  to  its 
position  on  the  labial  surface,  and  the  position  of  its  end  distinctly 
marked  upon  the  band,  to  serve  as  a  guide  to  soldering. 

When  the  hoods  are  completed  in  this  way  and  finally  all  placed  on 
the  tooth  and  perfectly  fitted,  an  impression  should  be  taken  for  fitting 
and  soldering  the  upright  bars  as  described  for  the  protrusion  apparatus. 


INDEX. 


ABSCESS,  acute  alveolar,  clinical  history 
of,  473 
discharging    through   gum   margin, 

483 
treatment,  477 
alveolar,  in  cachectic  individuals,  treat- 
ment of,  491 
at  the  bifurcation  of   roots  of    molar, 

487 
diagnosis  and  prognosis,  475 
with  fistula,  treatment  of,  478,  480 
primary  seat  of,  469 
aspiration  of  its  contents,  484 
blind,  469 

caused  by  erupting  third  molar,  488 
chronic  alveolar,  clinical  history  of,  474 
treatment  of,  483 

by   extraction   and    implantation, 
487 
with  fistulous  opening,  485 
upon  lower  molar  the  cause  of  oedema  of 
the  glottis,  477 
teeth,  exit  of  pus  through  under  jaw 
or  chin,  471 
teeth  with  living  pulp,  482 
temporary  teeth,  490 
symptoms  of,  490 
treatment  of,  490 
Accidents  during  extraction,  604 
Acid,  carbolic,  in  the  treatment  of  caries, 
169 
metaphosphoric,  320 
orthophosphoric,  320 
Aconite  and  chloroform,  399 
Actinomyces  in  root-canal,  121 
Acute   apical  abscess  discharging  through 

gum  margin,  483 
Administration  of  nitrous  oxid,  623 
Adrenalin  chlorid  in  the  extirpation  of  the 

pulp,  405 
Ainsworth  punch,  201 
Air,  warmed,  in  the  treatment  of   caries, 

187 
Allis'  ether  inhaler,  173 
Alloy  of  tin  and  cadmium,  of   silver  and 

copper,  289 
Alveolar  abscess,  acute,  discharging  through 
gum  margin,  483 
treatment  of,  477 
at  the  bifurcation  of  roots  of  molar,  487 
in  cachectic  individuals,  treatment  of, 

491 
chronic,  with  fistulous  opening,  485 
treatment  of,  483 


Alveolar  abscess,  complications  of,  488 
in  deciduous  teeth,  treatment  of,  674 
with  fistula,  treatment  of,  478,  480 
periostitis,  a  symptom  of  syphilis,  462 
process,  absorption  of,  512 

changes  in,  by  tooth  movement,  712 
description  of,  565 
resorption  of,  566 
Alveoli   of    permanent    teeth,    lower   jaw, 
567 
upper  jaw,  566 
Amalgams,  212 
binary,  296 

for  cavities  in  deciduous  teeth,  670 
classification  of,  296 
color  of,  294 

contraction  and  expansion  of,  291 
copper,  296 

discoloration  of,  258,  295 
edge  strength,  213,  294 
etymology  of  the  word,  290 
filling  up  the  cervical  portion  of  approx- 
imal  cavities,  329 
finishing  of,  309 
flow  of,  292 

trimming  the  margins  of,  308 
formulae  of,  214 
freshly  and  old  cut,  292 
and  gold  in  combination,  338 
good,  for  distinguishing  features  of,  213 
mixing  of,  301 

the  nature  of,  from  a  chemical  standpoint, 
290 
and  properties  of,  290 
packing  of,  303 
physical  properties  of,  291 
ternary,  296 

thermal  conductivity  of,  296 
a  tooth  saver,  355 
use  of,  299 
washing  of,  298 

and  zinc  phosphate,  combination  of,  217 
Ames'  copper  cement,  666 
Anatomy,  macroscopic,  of  teeth,  17 

topographical,  of  pulp  chambei-s,  431 
Anchorage,  details  of,  749 
intermaxillary,  752 
occipital,  751 
principle  of,  748 
reciprocal,  751 
simple,  750 
stationary,  750 
Anesthesia,  complete,  symptoms  of,  625 
signs  of,  612 

887 


888 


INDEX. 


Anehtbetics,  administration  of,  to  patients 
sntlering  from  cardiac  diseases,  tJlU 
general,    examination    of    patient    Ijefore 
administration  of,  01(1 
extractions  nnder,  60!i 
local,  in  tooth  extraction,  t)31 
Angle's  regulating  appliance,  729 

trays,  721 
Annealing  gold,  284 
tray,  electric,  285 
Antimony  chlorid  in  the  treatment  of  ex- 
posed cement  iim,  172 
Antisepsis  in  dentistry,  117 
Antise|)tics,  list  of  most  reliable,  126 

property  of  brass,  oOl 
Antrum,  artificial   opening  into,  to  remove 
pyogenic  collection,  490 
empyema,  symptoms  of,  4Si) 
how   to  abort  certain  cases  of  empyema, 
489 
Apical  region,   how    to  secure  an  entrance 

to,  462 
Appliances  for  the  administration  of  nitrous 

ox  id,  613 
Approximal    cavities   in   deciduous   teeth, 
treatment  of,  665 
spaces,  on  the  preservation  of,  521 
Arch,  upper,  widening  of,  787 
Arches,  expansion,  adjustment  of,  757 
Aristol,  419 
Ai'senical  application,  injudicious,  the  cause 

of  pericemental  irritation,  465 
Areenous    acid    for   the   devitalization   of 

pulps,  408 
Ash  electric  oven,  380 
Asphyxia  as  caused  by  nitrous  oxid,  623 
Astringent  mouth-wash,  502 

preparation,  501 
Atheromatous     changes     in    pericemental 

bloodvessels,  510 
Autoinfection  from  mouth  ]>arasites,  121 
Automatic  pluggei-s,  description  of,  239 

BAKER  anchorage,  730 
combinations  for,  762 
Baking  inlays,  367 
Rinds,  plain,  adjustment  of,  757 
for  regidating  ])urposes,  744 
"  Balsanx)  del  deserto,"  423 
Barton's  head  bandage,  607 
Bicuspids,  buccal  cavities  in,  187 

cases  in   which  their  early  extraction  is 

indicated,  871 
cavities  on  mesial  and  distal  surfaces  of, 

192 
disto-occlusal  cavities  in,  197 
filling  with  gold  of  cavities  upon  the  buc- 
cal surfaces  of,  243 

lingual  surfaces  of,  244 
of  compound  cavities  in,  249 
of  simple  approximal  cavities  in,  247 
lower,  34 

extraction  of,  597 
fii-st,  description  of,  34 
pulp  chambers  and  canals  of,  435 
second,  description  of,  36 
mesio-disto-occlusal  cavities  in,  155,  198 


Hicuspids,  ocduso-lingual  cavities  in,  198 
simple  cavities  in  the  exposed  surfaces  of, 
184 
filling  of,  with  gold,  242 
upper,  32 

extraction  of,  593 
first,  description  of,  32 

pulp  chamber  and  canal  of,  432 
function  of,  32 
second,  description  of,  34 

pulp  chamber  and  canal  of,  433 
Bing's  pluggers  for  non-cohesive  gold,  237 
Black's  1,  2,  3  mixture,  464 
Bleacheil  organic  debris  in  dentinal  tubuli, 
to  prevent  subsecjuent  alteration  of, 
536,  637 
Bleaching  action  of  hydrogen  dioxid,  538 
agents  of  the  oxidizing  type,  528 

reducing  tyi)e,  528 
with  chlorin,  Truman's  method,  534 
with    hydrogen    dioxid,    description    of, 
method,  539 
Harlan's  method,  539 
of  manganese  stains  in  teeth,  547 
of  mercurial  stains  in  teeth,  547 
methods  for  special  stains,  546 
preparation  of  tooth  for,  531 
the  result  of  alteration  in  the  color  mole- 
cule, 530 
of  silver  stains  in  teeth,  547 
with  sulfurous  acid,  542 
teeth    in    which    it    is   not    advisable   to 
attempt,  531 
Blind  abscess,  469 

description  of,  483 
Blood,  presence  of  urates  in,  508 
Blood-letting  in  pericementitis,  461 
Brass,  antiseptic  i)roperty  of,  501 
Breathing    during    the   administration   of 

nitrous  oxid,  624 
Broaches  for  canal  treatment,  438 
Brophy's  hand  matrices,  277 

furnace,  377 
Bunodont,  complex-crown  tooth,  37 
Burs,  dentate  fissure,  437 


CACHECTIC   conditions,  a    strong    pre- 
disposition    to     microbic    invasion, 
468 
Calcareous  deposits,  manner  of  detaching, 

501 
Calcic  inflammation,  496 
Campho-phenique  in  root  canal  treatment, 

481 
Canada  balsam,  327 
Canal  cleansing,  441 

filling  in  cases  of  bleaching,  533 

method  of  entrance  to,  443 

tortuous,  how  to  fill  with  gutta-percha, 

453 
treatment  of,  445 
instnmients  for,  437 
Canines,  cavities  upon   the  incisal  edge  of, 
189 
labial  surfaces  of,  188 
lingual  surfaces  of,  189 


INDEX. 


889 


Canines,  compound  cavities  in,  193 
deciduous,  description  of,  49 
filling  with  gold  of  cavities  upon  the  labial 
surfaces  of,  244 
compound  cavities  in,  247 
simple  approximal  cavities  in,  246 
impacted,  584 
lower,  30 

moving  the  roots  of,  872 
retracted,  retention  of,  779 
simple  approximal  cavities  in,  190 
upper,  description  of,  28 
extraction  of,  593 
pulp  chamber  and  canal  of,  432 
Carbolic  acid  in  combination   with  tannic 
acid,  169 
in  treatment  of  caries,  169 
Caries,  absence  of,  in  teeth    affected    with 
constitutional  pyorrhea,  504 
carbolic  acid  in  the  treatment  of,  169 
instruments  for  the  removal  of,  389 
the  result  of  septic  apical  pericementitis, 

476 
silver  nitrate  in  the  treatment  of,  172 
vulnerable  points  for  the  recurrence  of, 

258 
warm  air  in  the  treatment  of,  167 
zinc  chlorid  in  the  treatment  of,  169 
Carious  cavities,  chemical  treatment  of,  167 
Cataphoresis,  155,  406 
its  application  to  the  bleaching  of  teeth, 

543 
cathode  for,  166 
technique  of  administration,  163 
Cataphoric  bleaching  of  teeth,  543 
Cathode  for  cataphoresis,  166 
Causes  of  den  to-alveolar  abscess,  467 

tooth  discoloration,  523 
Caustic  pyrozone,  538 

Cavities  approaching  the  pulp,  precautions 
when  filling  with  amalgam,  307 
approximal  in  anterior  teeth,  filling  of, 
with  cohefeive  and  non-cohesive  gold, 
284 
in  deciduous  teeth,  treatment  of,  665 
buccal,  in  bicuspids,  187 
capped  pulp,  filling  of,  397 
classification  of,  184 
compound,  in  canines,  193 
in  incisors,  193 

filling  of  with  cement-amalgam  combi- 
nation, 332 
upon  bicuspids  and  molai-s,  filling  of, 
with  gold,  249 
incisore  and  canines,  filling  of,  with 
gold,  247  _ 
in  deciduous  incisors,  treatment  of,  669 
teeth,  filling  of,  with  amalgam,  669 
with  cement,  668 
disto-occlusal,  in  bicuspids,  197,  198 

in  molars,  197,  198 
extending  beneath  the  gum,  filling  of,  with 

amalgam,  307 
filling  of,  with  combinations  of  several 
filling  materials,  329 
metallic  foils,  227 
lining,  218 


Cavities,  lining,  with  zinc  cement,  355 
on  mesial  and  distal  surfaces  of  bicuspids, 
192 
molars,  192 
mesio-occlusal  in  bicuspids,  195 

molars,  195 
method  of  opening,  388 
occlusal,  184 

in  deciduous  teeth,  treatment  of,  663 
occluso-buccal,  in  lower  molars,  197 
-lingual,  in  bicuspids,  198 
in  molars,  198 
partial  filling  of,  with  soft  gold,  348 
preliminary  preparation  of,  149 
preparation  of,  175 

in  buccal  surface  of  upper  molar,  74 
inlays,  360 

major  class  for  matrix  work,  266 
shaping,  180 

simple  approximal,  in  bicuspids  and  mo- 
lars, filling  of,  with  gold,  247 
canines,  190 
incisors,  190 
and  canines,  filling  of,  with  gold,  246 
exposed  surfaces  of  bicuspids  and  nio- 
lars,  filling  of,  with  gold,  242 
molars  and  bicuspids,  184 
filling  of,  with  cement-amalgam   com- 
bination, 330 
in  temporary  teeth,  filling  of,  with  tin- 
gold,  351 
treatment  of,  enamel  margins,  183 
upon   buccal   surfaces   of  bicuspids   and 
molai-s,  filling  of,  with  gold,  243 
incisal  edge  of  incisors,  189 
labial  surfaces  of  canines,  188 
incisors,  188 

and  canines,  filling  with  gold,  244 
lingual  surfaces  of  bicuspids  and  mo- 
lai"s,  filling  of,  with  gold,  244 
canines,  189 
walls,  fracture   of,  during  filling   opera- 
tion,  258 
which  the  employment  of  the  matrix  is 
indicated,  264 
Cellular  necrosis,  467 
Cellulitis,  477 

treatment  of,  with   lead-water  and  laud- 
anum, 482 
Cement  and  alloy  in  combination,  351 
amalgam  and  gold  in  combination,  342 
effect  of  atmospheric  conditions  upon,  322 
fillings,  finishing  of,  324 

polishing  strips  for  the  finishing  of,  324 
and  gold  combination,  337 
method  of  filling  cavities  with,  324 
mineral,  215 
Cementoblasts,  103 
Cementum,  92 

continuous  formation  of,  93 

exposed  by  caries,  antimony  chlorid  in 

the  treatment  of,  172 
function  of,  56,  92 
histological  description  of,  92 
hypertrophy  of,  95 
Cervical  margins,  exposure  of,  148 
Chappell  plugger  points,  242 


890 


INDEX. 


Chart  reconl,  13^ 
Cliin  retractor,  737 
Cliisi'ls,  enamel,  437 
Clilorin,  affinity  for  hydrogen,  529 
for  bleaeliing,  o28 

Truman's  method,  534 
how  it  acts  as  a  bleacher,  529 
liberation  from  calcium  hypochlorite,  535 
methods,  537 
properties  of,  529 
Chlorinated  lime,  535 

application  of,  for  bleaching,  535 
Chloro-percha  for  tilling  root  canals,  423 

in  root  canal  therapeutics,  453 
Clamps,  204 

bands,  adjustment  of,  754 
the  Woodward,  245 
Coagulation  necrosis,  510 
Cobalt,  j)owdered,  as  a  devitalizer,  410 
Cocain  administration  by  Schleich's  method, 
1)33 
compounds  resulting  from  the  boiling  of, 

632 
dangers  accompanying  the  injection  of, 

636 
dose  of,  internally  and  hypoderniically, 

632 
injections,  technique  of,  635 
physiological  antidote  of,  632 
in  pulp  extirpation,  405 
respiratory  and  cardiac  paralysis  follow- 
ing the  administration  of,  632 
solution  for  hypodermic  injection,  633 
Cocoa  butter  to  prevent  adhesion  of  cement 

to  instruments,  344 
Cohesive  gold  foil,  231 

objections  to  the  use  of,  in  connec- 
tion with  the  matrix,  263 
and    non-cohesive   gold    in    combination, 
details  concerning  the  insertion  of, 
272 
Cold,  the  anesthesia  producing  power  of,  631 
Combination  fillings,  329 
Complications  of  alveolar  abscess,  488 
Conclusions   on   the   cause,  pathology,  and 
treatment  of  pyorrhea  alveolaris  of 
gouty  origin,  520 
Constitutional  origin  of  pyorrhea  alveolaris, 
503 
treatment  of  pyorrhea  alveolaris  of  gouty 
origin,  516 
Construction  of  regulating  ajipliances,  726 
Contour,  treatment  of  fillings  with  respect 

to,  221 
Contouring  apparatus,  877 
Copper  amalgam,  296 

Kirk's  method  of  preparing,  296 
manipulation  of,  307 
and  nickel  stains  in  teeth,  546 
oiyphosphate,  269 
Cotton  for  filling  root  canals,  450 
Counter-irritation  of  the  gum,  399 
Cocain  preparations,  631 
Crenshaw  matrices,  281 
Crowns,  artificial,  on  natural  roots  for  plan- 
tation operations,  649 
Cryer's  spiral  osteotome,  602 


Crystal  gold,  233 

mat  gold,  234 
Cushing's  scalers,  500 
Cuspid,  upper.     {See  Canine.) 

D -BANDS,  731 
Dangers  accompanving  the  plantation 
of  teeth,  648  " 
of  cocain  administration,  636 
Decay,  removal  of,  178 
Deciduous  teeth,  abscess  upon,  490 
absorj)tion  of  the  roots  of,  108 
duration  of,  ()59 
extraction  of,  591 

indications  for  the  extraction  of,  549 
management  of,  657 
Dental  arch,  18 

mesio-distal  relations  of,   in    cases  of 

Class  L,  785 
rounded,  19 
square,  19 
V-,  19 
square,  18 
tissues,  56 
Dentate  fissure  burs,  437 
Dentin,  chemical  analysis  of,  81 
disinfection  of,  319 
histological  description  of,  80 
hypersensitive,  general  anesthesia  in  the 
treatment  of,  172 
treatment  of,  149 

by  electrical  osmosis,  154 
percentage  of  inorganic  salts  in,  81 
precautions  to  prevent  discoloration  of, 
in  connection  with  pulp  devitaliza- 
tion, 409 
secondary,  87,  401 

sensitive,  effect  of  zinc  oxychlorid  upon, 
355 
silver  nitrate  in  the  treatment  of,  172 
Dentinal  fibrillae,  87 
tubules,  81 

direction  of,  82 
tubuli,  sterilization  of,  448 
Dentition,  pathological,manifestationsof,657 
Dento-alveolar  abscess,  466 

causes  of,  467 
Deposits  upon  teeth,  removal  of,  500 
Development  of  esthetic  facial  contour,  849 
Devitalization  of  the  pulp,  407 

deciduous  teeth,  672 
Devitalizing  fiber,  672 
Diamond  points  and  disks,  360 
Diet  in  pyorrhea  alveolaris  of  gouty  origin, 

518 
Difficulties  in  the  extraction  of  lower  third 

molars,  600 
Dioxid  bleaching  methods,  538 
Diplococcus  pneumoniae   in   dento-alveolar 
abscess,  467 
pulp  infection,  417 
Discoloration  of  amalgam,  258 

process,  i-ationale  of,  524 
Discolored  teeth  and  their  treatment,  523 
Disk  mandrel,  257 

Donaldson's  pulp  canal  cleansers,  439 
Downie  furnace,  377 


INDEX. 


891 


EBSTEIN   on    the    deposition   of   uratic 
salts,  509 
Electric  current,  conditions  influencing  the 
tolerance  of  teeth  to,  165 
mallet,  description  of,  239 
oven,  Ash's,  380 
warm-air  syringe,  168 
Electrical  osmosis  in  the  treatment  of  hyper- 
sensitive dentin,  154 
Elevators,  562 

manner  of  manipulating,  586 
Empyema  of  the  antrum  difficult  to  abort, 
489 
symptoms  of,  489 
Enamel,  chemical  composition  of,  58 
chisels,  437 
derivation  of,  56 
description  of,  56 
function  of,  56 

interprismatic  or  cementing  substance,  59 
margins,  finishing  of,  183 
rods,  59 

description  of,  60 
sections,  action  of  acids  upon,  58 
striation,  62 

structural  elements  of,  59 
walls,     histological      requirements      for 
strength  in,  69 
treatment  of,  in  the  preparation  of  cav- 
ities, 181 
Engine  mallet,  description  of,  240 
Eroded  areas,  treatment  of,  260 
Esthetic  facial  contour,  development  of,  849 
Ether,  administration  of,  611 

advantages  of,  for  extracting,  611 
anesthesia,  first  stage  of,  in  the  treatment 

of  hypersensitive  dentin,  172 
inhaler  for,  173 
Ethereal  varnishes  to  protect  the  pulp,  323 
Ethyl  and  methyl  chlorid,  631 
Etiology  of  mal-occlusion,  707 
Eucain,  636 

Examination  of  patient  before  administra- 
tion of  general  anesthetic,  610 
Excavator's,  178 
Excementosis,  95 
Expansion  arch  E,  730 
Experiments  with  gutta-percha  as  a  filling 

material,  317 
Exposure  of  the  pulp,  387 
Extension  for  prevention,   where    contra- 
indicated,  270 
Extracting  instruments,  552 

with  patient  in  bed,  585 
Extraction  accidents,  604 
of  crowded  teeth,  606 
of  deciduous  teeth,  indications  for,  549 
of  impacted  lower  third  molars,  601 
infection  following,  123 
injudicious,  the  cause  of  facial  deform- 
ities, 699 
lancing,  to  facilitate,  588 
lower  anterior  teeth,  596 
bicuspids,  597 
first  molar,  598 

and  second  molars,  594 
second  molar,  599 


Extraction,  lower  teeth,  forceps  for,  562 

third  molar,  599 
pointers  on,  625 
of  teeth,  549 

under  nitrous  acid,  621 
treatment  after,  604 
under  general  anesthetics,  609 

local  anesthetics,  631 
of  upper  bicuspids,  593 

canines,  593 

central  incisor,  592 

latei"al  incisor,  592 

third  molar,  595 

FACE,  changeable  area  of,  853 
portion  of,  affected  by  dental  regulat- 
ing appliance,  853 
unchangeable  area  of,  853 
Facial  art,  694 

deformity,  due  to  lingual  inclination  of 

front  teeth,  859 
orthopedia,  principles  of,  853 
Faught's  gutta-percha  packing  instrument, 

313 
Fennentation,  457 
Fibrillse,  dentinal,  87 
Fibroblasts,  102 

Files  for  trimming  approximal  fillings,  255 
Fillings  admitting  of  repair,  257 

burs  and  points  used  in  the  finishing  of, 

253 
finishing  of,  253 

of  gutta-percha  by  W.  Storer  How's  im- 
proved method,  314 
made  in  connection  with  matrices,  finish- 
ing of,  275 
material  for  deciduous  teeth,  663 

factors  to  consider  in  the  selection  of, 

227 
plastic,  history  of,  289 

properties,    uses   and  manipulation, 
289 
qualities  it  should  possess,  227 
for  root  canals,  421 
selection  of,  209 

table   showing   the   characteristics  of, 
354 
the  opei-ation  of,  with  metallic  foil,  227 
repairing  of,  257 
root  canals,  449 

temporary,  of  gutta-percha,  311 
in  the  treatment  of  hypei-sensitive  den- 
tine, 173 
treatment  of,  with  respect  to  contour,  221 
Finishing  fillings,  253 
Flagg's  gutta-percha  heater,  313 
Fletchers  carbolized  resin,  668 
Foil  crimpers,  350 

Forceps,  antiseptic,  for  lower  molar,  553 
for  extraction,  626 

description  of,  552 
manner  of  handling,  588 
Forces  governing  mal-occlusion,  684 

normal  occlusion,  681 
Formaldehyd,  high  antiseptic  value  of,  479 
investigations   on   the  germicidal  power 
of,  126 


892 


INDEX. 


Formaldehyd  lamps,  1*28 
Formalin,  418,  44S 

storilizatiDii  of  canals  with,  484 

in  till-  treatment  of  root  canals,  481 
Forms,  normal,  of  teeth,  582 
Fracture  of  cavity  walls  durinj^  filling,  258 

of  incisal  edge  of  anterior  tooth,  259 

of  tuberosity   of    maxilla  during   extrac- 
tion, GOG 
Furnace,  Ash's  electric,  380 

Hrojjhy,  .'577 

l)owiiie,  .■>77 

for  fusing  porcelain,  377 

gasoline,  377 

llanuuond,  379 

Jenkins,  377 

Turner,  377 

GASOLINE  furnaces,  377 
(iatcs-dlidden  pulj)  canal  drills,  439 
Glass  fillings,  359 

mixing  tablet,  323 
Gold,  cohesive,  advantages  of,  353 
and  non-cohesive,  347 
objections  to  the  use  of,  in  connection 
with  the  matrix,  2G3 
combination  of  cohesive  with    non-cohe- 
sive, ill  matrix  work,  details  concern- 
ing the  insertion  of,  272 
various  kinds  for  tilling  purposes,  345 
crvstal,  233 
mat,  234 

for  the  repairing  of  defective  gold  fill- 
ings, 257 
fillings,  finishing  of,  with  heavy  foils,  348 

material,  210,  227 
foil,  cohesive,  231 

proportion  of,  for  introduction  in  the 
cavity,  232 
non-coiiesive,  device  to  prepare   it   in 

rolls,  230 
to  remove  excess  of  mercury,  308 
forms  of,  for  filling  purposes,  228 
how  to  fill  root  canals  with,  453 
inlays,  356,  378 

Alexander's  method,  380 
introduction  of,  and  manner  of  adapting 

it  to  the  cavity,  235 
matrix,  method  of  obtaining,  374 
non-cohesive,  228 

advantages  and  disadvantages  of,  355 
foundation  of,  for  matrix  work,  274 
the  material  |)ar  excellence  for  filling 

in  connection  with  the  matrix,  2G4 
method  of  filling  cavities  with,  23G 
preparation   of,    in   foims   suitable  for 

introduction  in  cavities,  229 
(soft)  manipulation  of,  348 
and  platinum  for  filling  purposes,  234 
preparation  of,  for  matrix  work,  272 
principles  involved  in  the  condensing  of, 

236 
as  a  root-canal  filling  material,  421 
soft,  347 

stains  in  teeth,  546 
Steurer's  plastic,337 
and  tin  in  combination,  349 


Gold,  trinuner's,  255 

White's  crystal  mat,  337 
(iout,  articular,  509 

nervous,  509 

tegumentary,  509 

visceral,  509 
Gouty  diathesis,  meaning  of,  508 

predisposing  cause  of,  pyorrhea    alve- 
olaris,  505 

origin  of  abscesses  upon  teeth  with  living 
pulps,  482 

pericemeiuitis,  503,  512 
Guildford's  hanil  matrices,  278 
(iums,  healthy,  powerful  resistance  of,  117 

incision  in,  for  implantation,  652 

lanced,  (558 

-lancing  indications  for,  658 
objections  to,  657 

scissors,  563 

tumefied,  treatment  of,  502 
(iutta-j)ercha  and  amalg-am  in  combination, 
345 

and  cement  in  combination,  343 

classes  of,  310 

contraction  of,  in  cooling,  311 

experiments    to    determine    whether    it 
makes  moisture-tight  fillings,  317 

fillings,  changes  observed  in,  311 
finishing  of,  318 
material,  355 
root  canals,  449 

gold  combination,  345 

heater,  Flagg's,  313 

high  heat,  310 

history  of,  310 

how  to  fill  root  canals  with,  452» 

indications  for  its  employment,  311 

instruments,  313 

low  heat,  310 

mani[>ulation  of,  313 

medium  heat,  310 

origin  of,  309 

physical  properties  of,  311 

a  preserver  of  tooth-substance,  312 

softening  of,  313 

HABITS,  pernicious,  cause  of  mal-occlu- 
sion,  710  , 

Hammond  furnace,  379 
Hands,  preparation  of,  previous  to  opera- 
tions, 130 
Haplodont,  the  simple-crowned  tooth,  137 
Head,  anterior  transverse  section  of,  570 
bandages,  607 

posterior  view  of,  vertical  transvei"se  sec- 
tion, 571 
Headgear,  736 
Heater  for  gutta-percha,  315 
Hematogenic  calcic  pericementitis,  497, 506 
Hemoglobin  derivatives,  525 
Hemorrhage  after  extraction,  treatment  of, 
606 
systemic  treatment  of,  608 
therapeutic  treatment  of,  607 
Herbst  matrix,  301 

pliers,  300 
Hewett's  matrix,  279 


INDEX. 


893 


Hiatus  semilunaris,  574 
Histology,  dental,  with  reference  to  opera- 
tive dentistry,  54 
Hodson's  matrix,  280 
How's  improved  gutta-percha  fillings,  314 
Hydrogen,  affinity  of  chlorin  for,  529 
dioxid,  420 

action  of  aluminum  chlorid  upon,  539 
for  bleaching,  538 
Hydronaphtol  mouth-wash,  502 
Hygienic  treatment  of  pyorrhea  alveolaris 

of  gouty  origin,  517 
Hypersensitive  dentin,  first  stage  of  ether 
anesthesia  in  treatment  of,  172 
temporary  fillings  in  the  treatment  of, 

173 
treatment  of,  149 

IMMEDIATE  root  filling,  451 
1  Impacted  canines,  584 

loH^er  third  molars,  diagnosis  of,  600 
third  molars,  628 
Implantation,  639 
antiseptic  precautions  in,  124 
description  of  operation,  652 
Impression  taking,  722 

varnishing  of,  723 
Impurities  in  phosphoric  acid,  321 
Incisoi-s,  cavities  upon  the  incisal  edge  of, 
189 
labial  surfaces  of,  188 
central,  pulp  chamber  and  canal  of,  431 
compound  cavities  in,  193 
deciduous,  description  of,  48 

treatment  of  cavities  in,  669 
filling  of  cavities  upon  the  incisal   edge 
of,  246 
upon  the  labial  surfaces  of,  244 
upon  "the  lingual  surfaces  of,  245 
of  compound  cavities  in,  247 
of  simple  approximal  cavities  in,  246 
lateral,  pulp  chamber  and  canal  of,  432 
lower  central,  the  smallest  tooth  in  the 
arch,  27 
latei'al,  description  of,  28 
simple  approximal  cavities  in,  1 90 
the  third,  of  the  typal  mammal,  27 
upper  central,  description  of,  22 
extraction  of,  592 
andintermaxillaryprocessextended,861 
lateral,  description  of,  25 
on  the  eruption  of,  27 
extraction  of,  592 
suppressed  eruption  of,  27 
Infection,  external,  124 
through  extraction,  123 
from  mouth  to  mouth,  123 
from  rubber  dam,  118 
Inflammation  about  the  teeth,  severe  course 
of,    in    tuberculous    and    syphilitic 
patients,  468 
calcic,  496 
Inflammatory  action  the  cause  of  cellular 
necrosis  and  pus  formation,  467 
exudate,  peptonization  of,  483 
symptoms,  subsidence   of,  following   the 
exit  of  pus,  481 


Inhaler,  the  Thomas,  for  nitrous  oxid,  622 
Inlays,  advantages  of,  355 
color  variations  in,  370 
compared  with  other  fillings,  353 
definition  of,  353 
disadvantages  of,  353 
gold,  378 
hard-rubber,  382 
etching  of,  368 
insertion  of,  368 
porcelain,  357 

for  erosion  cavities,  260 
under  cutting  of,  368 
shading  of,  367 
Instruments  for  canal  ti'eatment,  437 
for  extracting,  552 
for  gutta-percha  work,  313 
used  in  extracting,  585 
Interglobular  spaces,  86 
Interproximal  space,  224 

polishing  of,  142 
lodin  in  pericementitis,  460 

in  the  treatment  of  septic  canals,  457 
Iodoform,  properties  of,  419 
Iron,  the  part  it  plays  in  the  discoloration 
of  teeth,  526 
stains  in  teeth,  546 
Irregularities  of  Class  I.,  treatment  of,  784 
11.,  Division  1,  818 

subdivision,  831 
treatment  of,  820 
Division  2,  833 

subdivision,  837 
III.,  subdivision,  847 
Irritation  following  the  removal  of  the  pulp, 
450 

JACK'S  matrices,  276 
Jack-screws,  735 
Jenkins  gas  furnace,  377 
Jumping  the  bite,  827,  856 

KAEBER  saw  frame,  309 
Kalium-natrium,  418,  539 
Kristaline,  327 

LABARRAQUE'S  solution,  418 
Lancets,  562 
Lancing  for  extraction,  588 
Lead  as  a  filling  material,  227 

-water  and  laudanum,  482 
Lee  matrix,  287 
Ligature  wire,  734 

adjustment  of,  757 
Line  of  occlusion,  686 
Lithium  bitartrate,  518 
Lodge's  matrix,  278 
Loop  matrices,  277 
Low's  formaldehyd  lamp,  128 
Lugol's  solution,  490 

Lymphatics,  involvement  of,  in  septic  peri- 
cemental inflammation,  468 
Lysol,  461 


M 


AGITOT  on  pyorrhea  alveolaris,  494 
Magnifying  lenses,  uses  of,  in  exam- 
ining teeth,  135 


894 


INDEX. 


Mal-occlusion  caused  bv  loss  of  permanent 
teeth,  70i» 
nas;il  obstnirtions,  711 
I>ernicious  habits,  710 
premature     loss    of    deciduous    teeth, 

707 
t;irdy  eruption  of  permanent  teeth,  709 
classilication  of,  Class  1.,  (585 

II.,  Division  2,  ()8G 
a  conunon  form  of,  684 
diagnosis  of,  087 
etiology  of,  707 
forces  governing,  684 
meaning  of,  677 
Mallet,  electric,  description  of,  239 

meciianical,  description  of,  240 
Mandrel  for  carrying  disks,  257 
Matrices,  Brophy  hand,  277 
Crenshaw's,  281 
devised  by  Dr.  Louis  Jack,  276 
linishing  of  fillings  inserted  by  the  aid 

of,  275 
forms  of,  for  molars  and  bicuspids,  276 
of.  the  loop  variety,  277 
the  making  of,  upon  models,  382 
for  molars  and  bicuspids  of  German  silver 

or  steel,  262 
for  use  in  connection  with  amalgam  work, 
300 
Matri.K  for  anterior  teeth,  282 

causes  of  failure  in  the  use  of,  263 
cavities  in  which   its  employment  is  indi- 
cated, 204 
continuous,  325 

gold,  instruments  for  the  making  of,  374 
method  of  obtaining,  373 
removal  of,  375 
Hewett's,  279 
Ilodson's,  280 
Lodge's,  279 
with  marginal  slits,  335 
for  molai-s,  2S1 
platinum,  362 

for  porcelain  inlays,  origin  of,  359 
qualities  it  should  possess,  261 
the  short-bar,  282 
the  true  purpose  of,  264 
u.se  of,  in  iilling  operations,  261 
work,  cjivity  preparation  for,  266 
pluggers  for,  271,  285 
preparation  of  gold  for,  272 
Ma.xilhe,  protrusion  of,  859 
Maxillary  arch,  retracted.  862 
retrusiim,  861 

sinus,  roots  forced  into,  during  extraction, 
605 
fragment  the  cause  of  abscess  in,  471 
projecting  into,  574 
of  upper  molar  protruding  into,  489 
Membrana  eboris,  87 
Meningitis  through  infected  teeth,  574 
Mercuric  chlftrid  effect  upon  albumin,  419 
Mercuiy,  action  of,  upon  metals,  291 

surplus,  removal  of,  304 
Metallic   .salts,    discoloration   of    teeth   bv, 

546 
Metaphosphoric  acid,  320 


Method  of  bleailiing  with  hvdrogcn  dioxid, 
539 
.sodium  dioxid,  5-50 
sepaniting  teeth,  145 
Micro-organisms  in  septic  imlps,  456 
Mwlels  for  orthodonlic  purposes,  720 

plane,  724 
Moisture,  methods  for  the  exclusion  of,  199 
Molai-s  and  bicuspids,  forms  of  matrices  for, 
276 
cavities  upon  the  lingual  surfaces  of,  187 

on  mesial  and  distal  surfaces  of,  192 
deciduous,  description  of,  49 
dist(K)cclu,sal  cavities  in,  197 
filling  with  gold  of  cavities  upon  the  buc- 
cal surfaces  of,  243 
compound  cavities  in,  249 
lingual  surfaces  of,  244 
simple  ajiproxiraal  cavities  in,  247 
the  fourth,  48 
lingual  tendency  of,  780 
lower,  42 
fii-st,  descrii)tion  of,  42 
extraction  of,  598 
pulp  cliambei's  and  canals  of,  435 
occluso-buccal  cavities  in,  197 
second,  desci-ijition  of,  44 
extraction  of,  599 
pulj)  chamber  and  canals  of,  436 
third,  47 

difficulties    encountered   in   the   ex- 
traction of,  600 
extraction  of,  599 
im])acted,  577 

diagnosis  of  the  position  of,  600 
indanunatory   phenomena   caused 
by,  603 
pulp  ciiamber  and  canals  of,  436 
matrix  for,  281 
mesio-disto-occlu.sal  cavities  in,  198 

-occlusal  cavities  in,  195 
occlu.so-lingual  cavities  in,  198 
restoration  with  amalgam  of  the  coronal 

distal  half  of,  308 
simple  cavities   on  the  exposed  surfaces 
of,  184 
filling  of,  with  gold,  242 
third,  abscess  caused  by  erupting,  488 

impacted,  628 
upper,  architecture  of,  38 
first,  description  of,  39 

pulp  chamber  and  canal  of,  433 
and  second,  extraction  of,  594 
formation  of,  38 
second,  description  of,  41 

pulp  chamber  and  canal  of,  433 
third,  46 

exti"action  of,  595 
pulp  chamber  and  canal  of,  434 
Morphin,  antidote  of  cocain,  632 
Mouth-opener,  mechanical,  564 

-pieces  for  the  administration  of  nitrous 

oxid,  614 
-props,  563 
-wash,  astringent,  502 
Mucous  membrane,  inflamed,  treatment  of, 
141 


INDEX. 


895 


Mummification  of  the  pulp,  424 
Mummifying  pastes,  426,  431 
Muscles  of  mastication,  how  aflected  by  im- 
pacted third  molar,  488 

NAPKINS,  use  of,  206 
Nasal  floor,  perforation  of,  by  abcesses 
upon  the  upper  teeth,  470 
obstruction,  the  cause  of  mal-occlusion,  71 1 
Nausea  due  to  the    introduction  into   the 
mouth   of    foreign  substances,  treat- 
ment of,  208 
Necrosis,  cellular,  467 
Nerves  of  the  pulp,  91 
New-departure  coi-ps,  290 
Nickel  stains  in  teeth,  546 
Nitrous  oxid,  613 

administration  of,  623 

according  to  Hewitt's  method,  616 
apparatus,  portable,  616 
appliances   for   an   administration    of, 

613 
extraction  of  teeth  under,  621 
inhaler,  622 
and  oxygen,  616 
safety  of,  621 
Nomenclature  of  orthodontia,  687 
Non-cohesive  gold,  228 
foundations,  274 

OBTUNDATION  by  cataphoresis,  406 
Obtundent  of  dentin,  320 
Occlusal  cavities,  184 

in  deciduous  teeth,  treatment  of,  663 
filling  with  cement,  324 
Occlusion,  the  first  molars  in  key  of,  679 
the  line  of,  686 

the  horizon  of,  19 
normal,  forces  governing,  681 

importance  of,  in  the  treatment  of  irreg- 
ularities, 677 
typical,  678 
molars,  681 
Odontalgia  in  children,  660 
Odontoblastic  cells,  87 

processes,  88 
CEdema  of  the   glottis   caused  by  abscess 

upon  lower  molar,  477 
Oil  of  cinnamon,  420 

tendency  to  discolor  the  dentin,  459 
essential,  in  canal  sterilization,  418,  420 
thyme,  420 
Oral  diseases,  transmission  of,  120 

fluids,  effects  of,  an  acid  condition  of,  151 
Orthodontia,  677 
definition  of,  677 
nomenclature  of,  687 
Orthopedia,  facial,  principles  of,  853 
Orthophosphoric  acid,  320 
Osteoblasts,  108 

peridental,  106 
Osteomyelitis  as  the  result  of  septic  peri- 
cementitis, 469 
Ottolengui's  reamers,  654 
Oxidizing  bleachers,  528 
Oxygen  and  nitrous  acid,  616 
Oxyphosphate  cement,  mixing  of,  322 


PALLADIUM  amalgam,  296 
Paraffin  for  filling  root  canals,  424,  454 
Pathology  of  constitutional  pyorrhea  alveo- 
laris,  507 
of  pyorrhea  alveolaris  of  gouty   origin, 

510 
of  septic  pericementitis,  468 
Patient,  position  of,  for  extraction,  584 
Perforated  roots,  491 
treatment  of,  492 
Pericemental  vessels,  atheromatous  changes 

in,  510 
Pericementitis,  acute,  non-purulent,  457 
blood-letting  in  the  treatment  of,  461 
cause  of,  459 

chronic,  without  apparent  pus  formation, 
457 
treatment  of,  463 
hematogenic  calcic,  506 
phagedenic,  482 
septic,  pathology  and  morbid  anatomy  of, 

468 
severe,  general  symptoms  of,  461 

treatment  of.  460 
symptoms  of,  459 
Pericementum.  (6'ee  Peridental  membrane.) 

a  point  of  minor  resistance,  510 
Peridental  membrane,  95 

bloodvessels  and  nerves  of,  115 
cellular  elements  of,  102 
changes  which  occur  with  age,  115 
disposition  of  its  Abel's,  99 
epithelial  structure  of,  109 
glands  of,  110 
punctures  of,  95 
structural  elements  of,  95 
osteoblasts,  106 
Phagedenic  pericementitis,  482,  496 
Phagocytosis,  468 
Pharyngeal  forceps,  564 
Phenol-sodique,  484 
Physical  examination  of  patient,  610 
Physiognomy,  examination  of,  855 
influence  of  the  teeth  on,  849 
relations  of,  to  the  saving  and  extraction 
of  teeth,  867 
Plantation  of  artificial  roots,  647 
of  teeth,  639 

description  of  operation,  650 
precautions   to  be  observed  in  connec- 
tion with,  648 
Planted  teeth,  mode  of  attachment,  647 

subsequent  care  of,  646 
Platinous  gold,  245 
Platinum  anode,  165 

matrix  for  porcelain  alloys,  362 
Pluggers,  automatic,  description  of,  239 
handles  adapted  for,  285 
for  matrix  work,  271,  285 
points,  selection  of,  241 
uses  of  the  sevei^al  varieties,  285 
Plugging  instruments,  236 
Polishing  cup  of  soft  rubber,  254 
Porcelain  cavity  stoppers,  358 
furnaces  for  the  fusing  of,  377 
high-fusing,  360 
inlays,  357 


896 


INDEX. 


I'urcelain  inlays  for  erosion  t-avities,  2()0 
tor  larj;*.'  cavities,  3tiS 
larj^i',  avoidance  of  excessive  contrac- 
tion, 'M\\) 
properties  of,  357 
low-fusing,  360,  372 
shrinkage  in  baking,  368 
tliat    can    be    melted    in    gold    matrices, 
372 
Ponltices,  a  pcrnicions  pnictice,  482 
Premolars,  lingnal  tendency  of,  780 
Preparation  of  cavities,  175 

of  cocain,  631 
Prescription  for  cocain  solution,  633 
Pressure  anesthesia,  405 
Proliles,  study  of,  854 
Properties  of  chlorin,  529 
Prophviactic  treatment  of  deciduous  teeth, 

"675 
Protrusion  apparatus,  882 

upper  dental  and  maxilhiry,  855 

due    to    labial  inclination    of   crowded 
front  teeth,  858 
Ptyalogenic  calcic  pericementitis,  498 
Pulp,  accidental  exposure  of,  393 
bloodvessels  of,  89 
calcific  changes  in,  401 
calcification  of,  402 
CJinal  cleansers,  Donaldson's,  439 
of  deciduous  teeth,  tilling  of,  673 
drills,  Gates-Cilidden,  439 
reaniei"s,  Walker's,  446 
capping,  395 

chambers  and  canals  of  lower   anterior 
teeth,  435 
bicuspids,  435 
first  molar,  435 
second  molar,  436 
third  molar,  436 
latenil  incisor,  432 
upper  central  incisor,  431 
first  bicuspid,  432 

molar,  433 
second  bicuspid,  433 

molar,  433 
third  molar,  434 
topogra])hi(al  anatomy  of,  431 
of  upper  canine,  432 
congestion,  catises  of,  523 

relief  of,  407 
conservative  treatment  of,  385 
death  of,  caused   by  tooth-movement,  716 
of  deciduous  teeth,  devitalization  of,  672    ; 
devitalization,  407  i 

diagnostic    value   of,  tiie    reaction  of,  to  \ 

thermal  tests,  390 
discoloration  of  teeth  following  the  death 

of,  527 
exposure,  387 

in  deciduous  teeth,  treatment  of,  661, 

671 
old,  treatment  of,  394 
recent,  treatment  of,  393 
stages  of,  392 

technical  treatment  of,  393 
extirpation  of,  405 
function  of,  58,  91 


I*ui|),  gangrenous,  micro-organisms  foimd  in 
cidturcs  from,  414 
histological  description  of,  87 
infected,  serial  decomposition  of,  416 
irritation  foHowing  the  removal  of,  450 
method  of  capping,  395 
minute  anatomical  elements  of,  385 
mununification,  424 
cause  of,  412 
techni(pie  of,  425 
mununified,  treatment  of  root  canals  con- 
taining, 455 
nerves  of  the,  91 
nodules,  diagnosis  of,  40)5 
normal    characteristics  and   pathological 

tendencies  of,  385 
protection     in     deciduous      teeth,     with 

Fletcher's    carbolized    resin,  668 
putrescent,  removal  of,  443 
recession  of,  in  teeth  afiected   with   con- 
stitutional pyorrhea,  504 
sensory  function  of,  91 
septic,  treatment  of  roots  with,  456 
sterilization  of,  393 
surgical  extirpation  of,  451 
tissue,    composition    of    its    proteid    ele- 
ments, 524 
vital  function  of,  91 
Punch,  Ainsworth's,  201 
Pus  formation,  long-continued,  about  roots, 
tendency  of,  483 
the  result  of  infianunatory  action,  467 
in  pericementitis,  surgical  removal  of,  462 
Putrefaction,  457 

Pyogenic  infection  of  hyoid  region  caused 
bv  septic  roots  of  lower  third  molar, 
489 
Pyorrhea  alveolaris  beginning  at  the  gum 
margin,  498 
causes  of,  498 
clinical  histoiy  of,  498 
diagnosis  of,  499 
pathology  and  morbid  anatomy 

of,  499 
treatment  of,  499 
of  constitutional  order,  503 
clinical  history  of,  503 
symptoms  of,  504 
origin  of,  497 
definition  of,  493 
diagnosis  of,  513 
Fauchard  on,  493 

of   gouty    origin,   conclusions    on    the 
cause.  ))athology,  and  treatment 
of,  520 
exciting  causes  of,  515 
predisposing  causes  of,  514 
treatment  of,  516 
history  of,  493 
literature  of,  493 
>ragitot  on,  494 
Riggs  on,  495 
terminology  of,  497 
treatment  of,  502 
complex  and  simplex,  520 
Pyrozone  solutions  in  the  treatment  of  root 
canals,  481 


INDEX. 


897 


Q 


UATEKNARY  amalgams,  298 


RADIOGRAPH  of  impacted  lower  third 
molars,  601 
Ray-fungus  in  root  canal,  121 
Reamers,  Ottolengui's,  654 

Younger,  655 
Reaming  of  root  canals,  441 
Recurrence  of  caries,  vulnerable  points  for, 

258 
Red  blood-corpuscle,  composition  of,  524 
Reducing  bleachers,  528 
Reflex  pain,  392 

in  the  ear,  399 
Regulating  appliances,  726 

Angle's,  adjustment  and  operation  of, 

753 
miscellaneous  combination,  765 
soft-soldering  of,  747 
soldering  of,  742 
tools  for  the  making  of,  739 
Repairing  of  fillings,  258 
Replantation,      conditions      following    the 
opei-ation,  640 
warranting  the  operation,  642 
technique  of,  487 

in   the    treatment  of    phagedenic     peri- 
cementitis, 643 
Resorption  of  alveolar  process,  566 
Retaining  devices,  temporary,  774 
Retention  devices,  permanent,  775 
principles  of,  773 
of  retracted  canines,  779 
of  teeth  after  regulating,  772 
time  required  for,  772 
Retrusions,    upper   dental    and    maxillary, 

861 
Retzius,  bands  of,  67 
Rhigolene,  631 

Riggs  on  pyorrhea  alveolaris,  495 
Robinson's  remedy,  169 
Root  amputation,  486 

of    anterior   teeth,  apparatus   for  retrud- 

ing,  884 
apparatus  to  change  the  position  of,  878 
artificial  plantation  of,  647 
canals,  cotton   as   a    filling  material  for, 
450 
filling  of,  449 

with  gutta-percha,  449 
immediate,  451 
materials  for,  449 
properties  it  should  possess,  421 
with  temporary  stopping,  326 
how  to  fill  with  gold,  453 
materials  tor  the  filling  of,  421 
reaming  of,  445 

salol  as  a  filling  material  for,  450 
septic  contents  of,  458 
with  septic  pulps,  456 
sterilization  of,  479 
sulfuric  acid  treatment  of,  442 
treatment  of,  after  intentional  removal 
of  pulp  en  masse,  415 
campho-phenique  in,  481 
and  filling,  412 

67 


Root  canals,  treatment  of,  with  mummified 
pulps,  455 
sulfuric  acid  in,  420,  447 
therapeutic  agents  used  in,  417 
when  shall  they  be  filled,  450 
of  deciduous  teeth,  absorption  of,  108 
demonstration  of,  in  chronic  abscess,  485 
extractors,  562 

forced    into    maxillary   sinus  during  ex- 
traction, 605 
forceps,  knuckle-joint,  554 
fracture  of,  during  extraction,  628 
perforated,  491 
cause  of,  491 
treatment  of,  492 
projecting  into  maxillary  sinus,  574 
temporary,  filling  of,  with  "balsamo  del 
deserto,"  491 
Royce  plugging  instruments,  346 
Rubber   dam,  application  of,  in  deciduous 
teeth,  667 
clamps,  204 
infection  from,  118 
placing  of,  202 

cavities  extending  under  gum   line, 
245 
use  of,  199 

SALIVA  ejector,  199 
exclusion  of,  without  the  rubber  dam, 
281 
Salivary  calculi,  removal  of,  142 
Salol,  disappearance   of,  from   root  canals,. 
455 
for  filling  root  canals,  424,  450,  454 
Sandarac  varnish,  327 
Sanguinary  calculus,  495 
Scaling  of  teeth,  500 
Schleich's  infiltration  anesthesia,  633 
Secretion,  altered,  from  labial  glands,  504 
Septic  destruction,  progress  of,  in  the  line 

of  least  resistance,  469 
Sheaths  of  Neumann,  81 
Silver  nitrate  in  the  treatment  of  deciduous 
teeth,  662 
of  sensitive  dentin  and  caries,  172 
-tin  alloys,  293 
Skiagraphs,  725 
Slip  matrices,  334 

Socket,  preparation  of,  for  plantation,  650 
Sodium  carbonate,  antiseptic  action  of,  420- 
dioxid,  antiseptic  action  of,  420 
for  bleaching,  538 

discolored  teeth,  459 
how  to  make  solutions  of,  458 
method  of  bleaching  with,  540 
properties  of,  540 
in  root-canal  treatment,  481 
solution,  how  to  make  it,  540 
sterilization  of  canals  with,  484 
in  the  treatment  of  septic  canals,  458 
Soft-soldering  of  regulating  appliances,  74T 
Soldering  pliers,  740 

regulating  appliances,  742 
Solila  gold,  337 
Spaces,  interglobular,  86 
Staphylococcus  pyogenes  albus,  512 


198 


IXDEX. 


Stapliyhx'occiis  pyogenes  aureus,  oTi 

eitreus,  512 
ISterili/^ition,  ajjents  usetl,  125 
of  dentinal  tuhuli,  448 
of  septic  canals,  47!* 
Stovaine,  the  anesthetic  propeities  of,  034 
Striatiuii  of  the  enamel,  02 
StnniHuis  I'oiHlilion,  4(kS 
Snlfi>nietlieni(>,i;l(>l)in,  /")2o 
Sulfurous  acid  for  bleaching,  542 
iSulphuric  aciil  in  root-canal  treatment,  420 

treatment  of"  root-canals,  442,  447 
Symptoms  of  complete  anesthesia,  025 
Syphilis,     tertiary,    alveolar    periostitis    a 

symptom  of,  402 
Syiinges  for  canal  treatment,  438 

warm-air,  lOS 
Systemic  disorders  originating    within  the 
mouth,  122 

TEETH,  abnormal,  583 
anterior,  tilling  of  approximal  cavities 
in,  with    cohesive  and  non-cohesive 
gold,  284 
matrix  for,  282 
ap])aratus  to  move  them  bixlily,  877 
appliances  used  in  examination  of,  134 
cleansing  of,  140 
crowded,  extraction  of,  606 
deciduous,  48 

(k'calcitication  of,  000 

erui)tion  of,  057 

filling  with  cement  of  cavities  in,  608 

material  suitable  for,  063 
premature   loss  of,   the    cause  of    mal- 

ot'clusion,  7u7 
prophylactic  treatment  of,  075 
treatment  of  alveolar  abscess  in,  674 
of  exposed  i)ulps  in,  671 
with  silver  nitrate,  662 
definition  of,  17 

discoloration  of,  following  death  of  pulp, 
527 
staining  of,  with  metallic  salts,  546 
discolored,    bleaching    of,    with    sodium 
dioxid,  459 
by  copper,  546 
by  gold,  546 
by  iron,  546 
by  nickel,  546 
their  treatment,  523 
eflect  of  uremia  on,  490 
evolution  of,  induceil  by  food-habit,  17 
examination  of,  133 
extraction  of,  549 
of  fishes,  17 

foims  and  position  of,  in  jaws,  572 
from    the     standpoint    of     comparative 

anatomy,  54 
fimction  of,  17 

with  living  i)ulp,  abscesses  upon,  482 
inmiediate  separation  of,  146 
influence  of,  on  the  physiognomy,  849 
loosened  by  jiyorrhea,  splints  for,  500 
lower  anterior,  extraction  of,  596 

pulp  chambers  and  canals  of,  435 
forceps  for  the  extraction  of,  562 


Teeth,  lower  occlusal  surfaces  of,  568 
macroscopic  anatomy  of,  17 
meclianii'al  ilesign  of,  17 
nietluMl  of  making  tap  openings  in,  444 
with  mummified  pulps,  diagnosis  of,  455 
normal  contact  of,  224 

forms  of,  582 
number  and  classes  of  22 
occlusion  of,  19 

parts  most  liable  to  carious  action,  137 
l)laiUation  of,  039 
planted,  mode  of  attachment  of,  047 

retention  of,  640 
of  poor    structure,  filling    material    >uit- 

able  for,  319 
preparation  of,  for  plantation  openitions, 

044 
purple    staining   of,    with    gold    chlorid, 

530 
relations  of,  in  normal  occlusions,  682 
of  the  physiognomy  to  the  saving  and 
extraction  {4,  867 
of  reptiles,  17 

restoration  of,  bv  cemented  inlavs,  353 
scaling  of,  500 

secondary  fiuutions  of,  in  man,  17 
se{)aration  of,  by  mechanical  means,  144 
bv  the   swelling  of   fibrous    materials, 
"146 
sound,  extraction  of,  piepanttory  to  the 

insi^rting  of  artificial  dentures,  551 
suitable  for  bleaching,  530 
supporting  tissues  of  the,  56 
teihni(]ue  of  examination  of,  137 
temperature  sense  of,  380 
tem|ioi-ary,  abr^cess  upon,  490 
tilling  ()f,  w  ith  tin-gold,  351 
ui»per,  occlusal  surface  of,  568 
Temperaments,    basal  and   binary  physical 

characteristics  of  the  teeth  of,  51 
Temperature  sense  of  the  teeth,  386 
Temporarv   roots,  filling  of,  with  "balsanio 
derdeserto,"  49l' 
sto|)ping,  32f) 

as  a  root  filling,  326 
teeth,  abscess  upon,  490 
Ternary  amalgams,  290 
Thermoscopic  heater  for  gutta-j^ercha,  315 
Thvniol,  420 

Tin  as  a  filling  material,  211,  227,  251,  355 
-gold,  349 

crim])ed,  350 
instruments  used  in  the  i)acking  of,  252 
shavings,  252 

shredded,  for  sealing  the  apices  of  canals, 
454 
Tissue  changes  incident  to  tooth-movement, 
712 
the  four  dental,  5(> 
resistance  of,  to  disease  causes,  468 
Tomes,  granidar  layer  fif,  85 
Tonic  preparations,  609 
Tooth-bleaching,  528 

discoloration,  cause  of,  523 
forms,  evolutions  of  from  the  simple  cone, 
17 


variations  of,  50 


INDEX. 


899 


Tooth-movement,  physiologic  changes  subse- 
quent to,  717 
tissue  changes  incident  to,  712 
natural  attachment  of,  640 
permanent,  indications  for  the  extraction 
of,  in  the   correction  of    mal-occlu- 
sion,  874 
Toothache  in  children,  treatment  of,  661 
Tophus  on  the  roots  of  teeth,  496 
Traction  screw,  767 
Ti-ansplantation,  639 

antiseptic  precautions  in,  124 
when  fii-st  noted,  639 
when  indicated,  644 
Treatment  of  abscess  upon  tempoiurv  teeth, 
490 
of  antral  empyema,  490 
of  chronic  alveolar  abscess,  483 
with  fistulous  opening,  485 
pericementitis,  463 
after  extraction,  604 

of  hypersensitive  dentin  with  chemicals, 
'    167 

with  general  anesthesia,  172 
with  temporary  filling,  173 
of  irregularities.  Class  I.,  784 

Class  II.,  Division  1,  818 
of  pyorrhea  alveolaris,  502 
of  gouty  origin,  516 
of  root  canals  with  formalin  solutions, 
481 
with  pyrozone  solutions,  481 
with  sodium  dioxid,  481 
of  roots  after  removal  of  deposits,  501 
Trephines,  Younger- Walker,  654 
Trichloracetic  acid  to  destroy  gum  tissue, 

488 
Trimmer,  approximal,  183 
Trinitrin,  properties  of,  632 
Tropacocain,  634 
Tuberculate  teeth,  37 
Tuberosity  of  maxilla,    fracture  of,  during 

extraction,  606 
Turner  furnace,  377 


u 


RATES  in  the  blood,  508 
presence   of,  in   deposits   upon   roots, 
512 
Uratic  salts,  Ebstein  on  the  deposition  of, 

509 
Uremia,  its  effect  on  the  teeth,  496 
Uric  acid  in  the  blood,  508 

diathesis  the  cause  of  pyorrhea,  497 


T/'ARNEY  plugger  points,  242 
V      Varnishes  for  lining  cavities,  327 
^  arnishing  impressions,  723 
Vulcanite  inhaler,  622 
inlays,  382 

WEBB  plugger  points,  242 
Wedging    a    cause     of     pus-exuding 
pockets,  511 
Weil,  the  layer  of,  88 
in  the  dentin,  88 
Weston  cavity  caps,  395 
Woodward  clamp,  245 
screw  matrices,  278 
Wright's  method  of  bleaching  teeth,  537 


X 


BANDS,  731 


yOUNGER  reamers,  655 

ZINC  cement  for  lining  cavities,  355 
chlorid,  action  of,  169 
conditions  which  render  its  use  inad- 
missible, 171 
effect  upon  albumin,  419 
method  of  using,  in  proximity  to  the 

pulp,  170 
as  an  obtunding  agent,  320 
root-canal  treatment,  448 
treatment  of  caries,  169 
composition  of,  318 
oxid,  320 

preparation  of,  320 
oxychlorid,  318 
cement,  215 

efiect   upon   sensitive  dentin   and   ex- 
posed gums,  355 
for  filling  root  canals,  422 
irritating  action  of,  422 

properties  of,  451 
properties  of,  318 
technique    of    filling  root  canals  with, 

451 
use  of,  319 
oxyphosphate,  advantages  and  disadvan- 
tages of,  355 
uses  of,  322  ^ 

oxvsulphate,  327 
phosphates,  227,  320 
cement,  216 
tooth-saving  qualities  of,  330 


' 

DATE  DUE 

Ullf   "ft  0 

ini     AMP 

o  A  7fU|4 

\\ju    y  / 

11 M     A'-.ib 

/O  9  ^U^IS 

'"^'l 

jMfe 

n  'J  7i]iD. 

tis 

If,  iL*  U'"^^  1 

l.t^»- 

Demco,  Inc.  38-293 

